Synthesis of a New Biocomposite for Fertiliser Coating: Assessment of Biodegradabilityand Thermal Stability

Synthesis of a New Biocomposite for Fertiliser Coating: Assessment of Biodegradabilityand Thermal Stability | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Synthesis of a New Biocomposite for Fertiliser Coating: Assessment of Biodegradability and Thermal Stability Mohammed Reza Ketabchi, Salman Masoudi Soltani, Andy Chan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2928168/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Jul, 2023 Read the published version in Environmental Science and Pollution Research → Version 1 posted 6 You are reading this latest preprint version Abstract The bio- and thermal degradation as well as the water absorption properties of a novel biocomposite comprising cellulose nanoparticles, natural rubber and polylactic acid have been investigated. The biodegradation process was studied through an assembled condition based on the soil collected from the central Malaysian palm oil forests located in the University of Nottingham Malaysia. The effects of the presence of the cellulose nanoparticles and natural rubber on the biodegradation of polylactic acid were investigated. The biodegradation process was studied via thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). It was understood that the reinforcement of polylactic acid with cellulose nanoparticles and natural rubber increases the thermal stability by ~20 °C. Limited amorphous regions on the surface of the cellulose nanoparticles accelerated the biodegradation and water absorption processes. Based on the obtained results, it is predicted that complete biodegradation of the synthesised biocomposites can take place in 3062 h, highlighting promising agricultural applications for this biocomposite. biocomposites biodegradation water absorption thermal stability kinetics Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1. Introduction Biodegradable materials are increasingly becoming popular - owing to their inherently safer disposal pathways. Many industries including packaging, biomedical, pharmaceutical, agricultural and horticultural, textile, household goods and automotive have been integrating the use of biodegradable materials into their end products [Nanda et al. 2021 , Imbachi-Hoyos et al. 2022 ]. According to the USA Biodegradable Products Institute (BPI) standards, biomaterials are classed as those which must disintegrate within 3-month (2160 h) of their production [Briassoulis et al. 2010 ]. Degradation involves fragmentation and changes in the molecular arrangements of materials. There are different types of degradation e.g. thermal degradation, thermos-oxidative degradation, direct and indirect photo-degradation, irradiation degradation, mechano-chemical degradation, chemical degradation and biodegradation [Teixeira et al. 2021 , Rohidi & Othman 2022 , Pires et al. 2022 ]. The degradation of biodegradable materials disposes various organic resources which could benefit the soil. During the natural degradation process (biodegradation), the process begins with photodegradation by UV light from the sun and the organic constituents are oxidised and converted to ecologically accepted molecules including minerals, water and carbon dioxide [Chellasamy et al. 2022 ]. According to the EN-13432 European standard, in the absence of oxygen, these biomaterials decompose into minerals, carbon dioxide and methane [Notaro et al. 2022]. These soil-friendly features have gained considerable attention among agricultural sectors. Biocomposites have both directly and indirectly (as a carrier) shown their applicability in the improvement of soil properties in several distinct ways [Akhir & Mustapha 2022 ]. Farmers have been using fertilisers for many decades to improve soil properties for enhanced cultivation. Fertilisers contain hydrophilic minerals and salts. Fast dissolution of these salts causes irrecoverable damages to both soil and plants’ nutrients’ uptake. To control the dissolution process, various methods have been investigated. One method is introduction of compounds with low water solubility and low volatility to slow down the dissolution process [Barra Caracciolo & Grenni 2022 ]. Through this method, the synthesised compounds release the nutrients over longer periods of time (slow release). This can be costly in practice, depending on the soil condition (temperature, oxygen level, pH) and plant’s needs [Malathi et al. 2021 ]. An alternative method to overcome this, is to encapsulate the actual fertiliser with organic compounds capable of progressively releasing the nutrients following its biodegradation in soil [Angelo et al. 2021 , Javazmi et al. 2021 ]. This results in gradual release of the nutrients synced with the continual biodegradation process. Depending on the target application, the biodegradation can be further tuned by adjusting the capsule thickness or employing more/less rigid compositions. This, in return, builds on more confidence in commercial viability of such biocomposites [Tripathi et al. 2021 ]. Biopolymers are extracted from natural resources such as corn, potato and sugarcane [Rego & Corrêa 2022 ]. They have become an alternative to petroleum-based plastics following their global availability and the facile cultivation of natural resources. Through different agricultural environments, plants are cultivated, harvested and then chemically and physically treated to extract their starch content. The isolated starch is then refined using special enzymes to produce a specific biopolymer [Lasprilla et al. 2012 , Apriyanto et al. 2022 ]. This product is fully biodegradable into mainly water and carbon dioxide. Biodegradable polymers are either plant- and bacterial-based or synthesised using a bio-based monomer. Polylactic acid (PLA) is a synthesised biopolymer comprising lactic acid monomers [Ahmad et al. 2022 ]. However, poor thermal and mechanical performance and also high production costs are the key drawbacks in large-scale applications of the PLA [Taib et al. 2022 ]. PLA has been reported to be well biodegradable; however, it suffers from low degradation rates when compared to other aliphatic biopolymers [Rosli et al. 2021 ]. In the early stages of PLA degradation, the PLA chains with high molecular weight (ester bonds) are hydrolysed to form lower molecular weight chains [Fukushima et al. 2012 ]. Amorphous regions provide higher hydrolysis rate compared to the crystalline counterparts [Sun et al 2013]. An increase in the biodegradation rate was observed following reinforcement of PLA with starch (an inherently amorphous material) which was ascribed to moisture absorption which benefits the hydrolysis process [Wu 2005 , Hernández-Carmona 2017]. On the other hand, an increase in the PLA crystallinity was reported to decrease its biodegradation rate [Urayama et al. 2002 , Shogren et al. 2003 ]. The introduction of a basic or an acidic solution to the soil, and an elevation in both the temperature and the humidity were found to facilitate these reactions [Avinc et al. 2010 ]. Degradation and mineralisation of the PLA has been stated to complete in 6480 h (9 months) and 84 h at 30°C and 70°C, respectively [Lunt 1998 ]. The biodegradation rate of the PLA plastic films in soil was reported at 28 mg in 24 h at 28°C with 27% conversation to CO 2 [Ho & Pometto 1999 ]. Higher degradation rates were observed at the sample core due to the high concentration of carboxylic acid groups which enhance the ester hydrolysis [Harmaen et al. 2015 ]. Meanwhile, bacterial and fungal microbes can act as a catalyser [Wilkes & Aristilde 2017 ]. Such microorganisms (polysaccharide utilisers) break ester bonds to an acid or an alcohol, which then form low-molecular-weight chains which in the end, convert into CO 2 , water and humus [Seshikala & Charya 2012 ]. Development of fungal mycelia on the PLA surface was reported after 8 weeks in soil [Shogren et al. 2003 ]. In this study, a new biocomposite was prepared as an encapsulating material for fertilisers. The biodegradation and water absorption behaviour of the synthesised biocomposite was determined (ASTM D256) and a polynomial model was developed. 2. Experimental procedures 2.1 Materials Polylactic acid (Ingeo biopolymer) (grade 2003 D, melt index: 6 g/10 min, density: 1.22 g/cm 3 ) was supplied by Nature Works LLC product, USA. The granules were dried at 60°C for 12 h prior to the compounding process. Synthetic liquid polyisoprene (LIR-30) (Molecular weight: 28000, Tg: -63°C by Kuraray Co. Ltd., Japan) was used as the natural rubber (NR). Cellulose nanoparticles (CNP) were extracted from kenaf fibre according to the optimised process obtained through our earlier study [Ketabchi et al. 2016 ]. The soil in this study was collected from the central Malaysian palm oil forests based in the University of Nottingham Malaysia. The soil had a pH of 6.5 (1:2 soil and water suspension) and did not contain any composting materials and showed no enzymatic activity. 2.2 Methods 2.2.1 Compounding process Nine different sets of compositions were prepared via melt compounding, followed by injection moulding (Table 1 ). All biocomposites were prepared using a Brabender PL2000-6 twin-screw compounder (180°C, 10 min and 100 rpm). All compounds were then moulded using a bench-top injection moulding machine (RR3400, RAY-RAN Injection Moulding Machine) at 180°C and 90°C for barrel and mould temperatures, respectively. Holding time was set at 8 seconds in accordance with the ASTM D256 method. Table 1 The compositions of the prepared samples Sample PLA content (wt. %) CNP content (wt. %) NR content (wt. %) PLA 100 - - PN1 99 1 - PN2 97 3 - PN3 95 5 - PR1 95 - 5 PR2 90 - 10 PR3 85 - 15 PR4 80 - 20 PNR 87 3 10 2.2.2 Biodegradation test The biodegradation process of the PLA-based biocomposites was carried out in a natural-soil environment, using accessible tools and materials [Harmaen et al. 2015 ]. The soil was free from any enzymatic activities and any compositing additive. Nine plastic containers (250 ml) were filled with identical amounts of soil samples (labelled according to Table 1 ). The biocomposite samples (~ 30 × 10× 3 mm) were then placed (buried) into each of the nine containers. The containers were next kept at room temperature (28°C) and with an ambient relative humidity of 80%. The experiment was continuously run for 2160 h. The biocomposites were subsequently weighed using a lab-scale balance. The change in the biocomposites’ masses was determined after 6, 12, 24, 48, 72, 96, 120, 1440, 1680, 1920, 2160 h after their initial burial in soil samples. Prior to any analysis, each biocomposite was first rinsed under tab water to wash out the soil residues and later dried at 80°C to fully remove the moisture until a constant dry weight was achieved. The initial ( i.e. before test) and the secondary ( i.e. after x hours) sample weights were recorded and labelled as S 0 and S 1 , respectively. The weight loss percentage was calculated using Eq. 1: Weight loss (%) = \(\frac{\text{S}0 - \text{S}1}{\text{S}0 }\text{*} 100\) Eq. (1) 2.2.3 Water absorption test The test was done according to the ASTM D 570 [Hosseinihashemi et al. 2016 ]. Plastic containers were used and filled with distilled water. The containers were kept at room condition (28°C, 80% humidity). The water level was maintained the same throughout the entire test run. The biocomposites were weighed initially and after 6, 12, 24, 48, 72, 96, 120, 1440, 1680, 1920, 2160 h of soaking in distilled water. Prior to each analysis, biocomposites were moderately dried using a towel to remove the excess water on the surface until a constant weight was obtained. The primary (before test) and secondary (after x hours) weights of the samples were recorded and labelled as W 0 and W 1 , respectively. The water absorption percentage was calculated using Eq. 2: Water absorption (%) = \(\frac{\text{W}0 - \text{W}1}{\text{W}0}\text{*}100\) Eq. (2) 2.2.4 Thermogravimetric analyses (TGA) Both of the non-biodegraded and biodegraded samples were used to determine the influence of biodegradation on the thermal stability of the biocomposites. Perkin Elmer simultaneous thermal analyser (STA 6000, USA) was used to run the themo-gravimetric analyses (nitrogen flow rate: 10 ml/min, temperature starting from 30°C to 500°C, a heating rate of 10°C/min. 2.2.5 Scanning electron microscopy (SEM) Biocomposites were recovered from soil after 2160 h of burial and their surface structure was analysed using a scanning electron microscope (FEI QUANTA 400F) at 20 kV. The surface morphologies were studied and compared with the un-buried biocomposite samples. 3. Results and discussion 3.1. Biodegradation in soil The results show that the biocomposites lose their weight by 0.61–3.70% (Fig. 1 ). Within the first 720 h of the burial in soil, the biocomposites were only slightly decomposed. Within the same test period, the weight of the PN2, PN3, PR1, PR4 and PNR increased by only 0.6%. This is associated with water uptake from the soil. A weight loss of just 0.61–2.08% was observed at the very early stage of the degradation process ( i.e. after 1440 h). The biodegradation process was more noticeable after 2160 h of burial where CNP/PLA biocomposites underwent a weight loss of ~ 3%. However, the NR/PLA biocomposites lost their weight by about 1.5%. Basically, a higher CNP and a lower NR content resulted in a faster biodegradation process. Consequently, the PN3 corresponded to the fastest observed biodegradation process. This is linked to the amorphous regions present in CNP which favourably affects the biocomposites’ resistance against degradation. CNP contains both crystalline and amorphous regions; however, a dominant crystalline region was detected as a result of the experimental conditions. Fair biodegradation of the biocomposites with CNP confirms the fact that amorphous structures are more easily attacked by hydrolytic enzymes which can result in much higher biodegradation rates [Liu et al. 2022 ]. This suggests the significant role of the amorphous regions in the biodegradation processes. Depending on the applications, further CNP treatment can be considered in order to tailor-make the degree of crystallinity. The decomposition of the PR4 was slower than that of any other studied biocomposites. This is associated with the hydrophobic nature of the NR which retains the PLA structure. Similar trend was also observed with the PNR which was linked not only to the nature of the NR but also to the enhanced interfacial adhesion between the PLA matrix and the CNP due to the addition of the NR. Therefore, the PNR composition exhibited a moderate degradation phase as compared to both the CNP/PLA and the NR/PLA biocomposites. The PNR showed a weight loss of 1.3% after 2160 h of the initial burial. 3.2. Water absorption Water absorption test was carried out in parallel with the soil burial test (Fig. 2 ). During the first 72 h of the test, most of the samples appeared to absorb only little amount of water. However, the PR4 and PNR samples began a considerable water absorption after 12 h. They both demonstrated the highest water uptake during the test: 3.14% for PR4 and 4.34% for PNR after 2160 h. The biocomposites with CNP had relatively lower water absorption rates as compared to the biocomposites with NR. This is linked to the strong crystalline structure of CNP and the preparation technique, minimising the hydrophilic nature of the fibre. Therefore, an increase in the CNP content shows a minor impact on the water absorption rate. On the other hand, an increase in the NR content, elevates water uptake. This is linked to the excess amount of NR in the PR4 which results in the formation of micro bubbles and voids in the sample. The performance of composite materials is highly dependent on the presence of pores as they influence the heat and mass transfer behaviour [Hosseinihashemi et al. 2016 ]. Most of the biocomposites showed a maximum water absorption of about 1% after 2160 h (expect for the PR4 and PNR). The PN2 and PR3 were associated with the lowest water absorption rates. This reveals that a combination of CNP (3 wt. %) and NR (15%) is the optimum amount of reinforcement in order to minimise the PLA’s water absorption. 3.3. Thermal degradation The thermal stability of the biocomposites was analysed via TGA analyses. Figure 3 illustrates the weight loss during the TGA test. All biocomposites began to degrade at about 320°C. At this temperature, the PN1 and PN2 both showed an 8% weight loss while the PN3 underwent a 5% weight loss. This trend became more noticeable at temperatures > 360°C. At this temperature, the PN1 showed a 70% weight loss compared to a 55% and a 48% weight loss for the PN2 and PN3, respectively. This reveals the effect of CNP on the thermal stability of the PLA at high temperatures. Meanwhile, the biocomposites with NR showed an opposite behaviour compared to the biocomposites with CNP. Higher concentrations of NR (> 10 wt. %) adversely impacts the thermal stability of the PLA. The excess NR was located between the PLA granules i.e. creating a gap between the granules, which in turn, affects the overall stability of the PR3 and PR4 at higher temperatures. Compared to NR, at such elevated temperatures, weight loss is mainly associated with the degradation of the cellulose fibres. Therefore, the PR2 shows the highest thermal stability among the biocomposites. The thermal studies together with the soil burial and water absorption tests successfully pinpointed the optimum PNR compositions ( i.e. 3 wt. % CNP and 10 wt. % NR). The reinforcement of PLA with both NR and CNP improved the thermal stability by almost 20°C. To further study the effect of biodegradation on the thermal stability of the biocomposites, three biodegraded samples were tested (tagged as PN’ (biodegraded PN), PR2’ (biodegraded PR2) and PNR’ (biodegraded PR2)). Figure 4 presents the thermal behaviour of the biodegraded samples for temperatures between 30°C and 450°C. The PN’ showed a higher thermal stability than the PN which is linked to the stability of cellulose. On the other hand, the PR showed a higher thermal stability than the PR’ which is associated with the biodegradation and the poor thermal stability of NR. At 360°C, the PN, PN’, PR2, and PR2’ lost about 40, 55, 28 and 40% of their total mass, respectively. The PNR and PNR’ demonstrated very similar thermal behaviour, indicating the thermal stability of the PNR despite the structural changes brought about by the biodegradation process. This is especially suitable in biodegradation applications deployed in tropical and/or hot countries e.g. Malaysia. 3.4. Morphological analyses The effect of biodegradation on the surface of the biocomposites after 2160 h of burial in soil was analysed using SEM micrographs (Fig. 4 ). Partial biodegradation of the PLA granules was observed which was due to microbial action rather than physical discharge [Shogren et al. 2003 ]. The presence of the cracks and holes confirmed the biodegradation process [Brzeska et al. 2022 ]. A greater number of cracks was observed on the biocomposites with higher rates of biodegradation ( i.e. PLA, PN3, and PR3). In addition to the cracks, the shrinkage of the biocomposites also facilitates the exposure of the CNP to moisture and its surrounding area [Harmaen et al. 2015 ]. Due to the reinforcement, compared to the PLA, fewer number of cracks were observed on the PNR surface resulting in a reduction in the biodegradation rate. The PNR is an appropriate fertiliser encapsulating material due to its suitable biodegradation process. Moderate biodegradation of the PNR can also stabilise and control the release of the fertiliser nutrients in soil. 3.5. Rate of biodegradation and water absorption As a fertiliser encapsulating material, it is critical to determine the time required for complete the biodegradation of the PNR and the corresponding water absorption rate. The soil burial and the water absorption test results were best fitted to a cubic polynomial model (Eq. 3), where Y is \(\frac{weight loss\%}{water absorption\%}\) ; X is the time factor; Y 0 , a, b and c are the four coefficients used in the cubic model. The applicability of the polynomial model was examined by assessing the regression coefficient (R 2 ). The results are presented in Table 2 . Y = Y 0 + aX + bX 2 + cX 3 Eq. (3) Table 2 Results of the cubic polynomial regression model for the soil burial test Test type Biocomposite Y 0 a b c R 2 Soil PNR 0.150 -0.0045 0.0000052 -0.0000000013 0.85 PLA -0.028 -0.0019 0.0000032 -0.00000000078 0.92 Water PNR 1.190 0.0096 -0.0000083 0.0000000021 0.81 PLA 0.089 0.00028 0.00000099 -0.00000000041 0.79 It is found that almost 3062 and 3863 h of soil burial is required for complete ( i.e. 100%) biodegradation of the PNR and PLA, respectively. The biodegradation process is considered fast as compared to similar studies reported in the literature [Jin et al. 2022 , 37, Sharma et al. 2021 ]. This was directly linked to the test conditions ( i.e. high humidity). The biodegradation rates of the PNR and PLA were measured to be about 0.15% and 0.03% per hour, respectively. In other words, the PNR, as a encapsulating material, can last for nearly 3072 h under tropical conditions, boasting a moderate biodegradation rate of about 0.15%/h. The water absorption rate was measured to be 1.2%/h and 0.08%/h for the PNR and PLA, respectively. Slightly higher biodegradation and water absorption rates are linked to the presence of the amorphous regions [Kovác & Tabi 2011, Dogu & Kaynak 2016 , Zamir et al. 2022 ]. It was understood that the CNP accelerates while the NR moderates the biodegradation of the PLA biocomposites. This is a further confirmation of the optimum composition used in the PNR biocomposites. 4. Conclusions In this study, indoor biodegradation, thermal degradation and water absorption processes for PNR biocomposites were investigated. The results were best described by a cubic polynomial model. The PNR biocomposites were observed to be biodegradable under natural conditions. Cracks and shrinkage in the biocomposites’ surfaces accelerated the exposure of the CNP to moisture and its environment. Amorphous regions in CNP were realised to play a key role in accelerating the PNR biodegradation. An increase in the biodegradation rate was also linked to the test conditions ( i.e. high humidity). The CNP accelerated while the NR moderated the biodegradation rate of the PNR biocomposites. The PNR demonstrated an acceptable water resistance when prepared with the optimum compositions. A composition comprising 3 wt. % CNP and 15 wt. % NR was observed to be the optimum amount of reinforcement in order to minimise the PLA’s water adsorption. An excess amount of NR in the PR4 biocomposites affected its morphology and led to a higher water absorption capacity. An improvement in the PLA thermal stability was achieved following the integration of both the CNP and NR. Labour and application costs may be reduced by using PNR as a fertiliser encapsulating material by eliminating the need for multiple fertilizer applications. Prolonged nutrient release may provide more uniform plant nutrition, better growth and improved plant performance. Master-batch preparation of the PNR/fertiliser is therefore, of great importance in future studies and investigations. The future studies include analysing the interaction between PNR/fertiliser master-batch and soil. Declarations Acknowledgment The authors would like to specially thank Dr Chantara Thevy Ratnam and Dr Mohammad Khalid for their assistance and input in this work. We would also like to acknowledge the University of Nottingham Malaysia for providing us with the research facilities to conduct this research. Ethical Approval Not applicable Consent to Participate Not applicable Consent to Publish All authors agree to publish their research data pertinent to the paper. Funding “The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.” Competing Interests “The authors have no relevant financial or non-financial interests to disclose.” Author Contributions “All authors contributed equally to the study conception and design. Material preparation, data collection and analysis were performed by Mohammad Mohammad Reza Ketabchi, Salman Masoudi Soltani and Andy Chan. The first draft of the manuscript was written by Reza Ketabchi and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.” Availability of Data and Materials “All data, raw and analysed, have been stored in the university repository and are available upon request. They are not made public due to contractual agreement. References A. Ahmad, F. Banat, H. Alsafar, S.W. Hasan, 2022, An overview of biodegradable poly (lactic acid) production from fermentative lactic acid for biomedical and bioplastic applications, Biomass Conversion and Biorefinery (in press). M.A.M. Akhir, M. Mustapha, 2022 Formulation of biodegradable plastic mulch film for agriculture crop protection: A review, Polymer Reviews (2022) 1-29. L.M. Angelo, D. França, R. Faez, 2021, Biodegradation and viability of chitosan-based microencapsulated fertilizers, Carbohydrate Polymers vol. 257, 117635. A. Apriyanto, J. Compart, J. Fettke, 2022, A review of starch, a unique biopolymer–structure, metabolism and in planta modifications, Plant Science vol. 318, 111223. O. Avinc, M. Wilding, D. Phillips, D. Farrington, 2010, Investigation of the influence of different commercial softeners on the stability of poly(lactic acid) fabrics during storage, Polymer Degradation and Stability vol. 95 no. 2, pp. 214-224. A. Barra Caracciolo, P. Grenni, 2022, Bioremediation of soil ecosystems from triazine herbicides, pesticides in soils: Occurrence, fate, control and remediation, The Handbook of Environmental Chemistry, pp. 353-377. J. Brzeska, G. Jasik, W. Sikorska, B. Mendrek, J. Karczewski, M. Kowalczuk, M. Rutkowska, 2022, Susceptibility to degradation in soil of branched polyesterurethane blends with polylactide and starch, Polymers vol. 14, 2086. D. Briassoulis, C. Dejean, P. Picuno, 2010, Critical review of norms and standards for biodegradable agricultural plastics Part II: Composting, Journal of Polymers and the Environment vol. 18, pp. 364-383. G. Chellasamy, R.M. Kiriyanthan, T. Maharajan, A. Radha, K. Yun, 2022, Remediation of microplastics using bionanomaterials: A review, Environmental Research vol. 208, 112724. B. Dogu, C. Kaynak, 2016, Behavior of polylactide/microcrystalline cellulose biocomposites: effects of filler content and interfacial compatibilization, Cellulose vol. 23, pp. 611-622. K. Fukushima, E. Giménez, L. Cabedo, J. Lagarón, J.L. Feijoo, 2012, Biotic degradation of poly (DL-lactide) based nanocomposites, Polymer degradation and stability vol. 97 no. 8, pp. 1278-1284. A.S. Harmaen, A. Khalina, I. Azowa, M.A. Hassan, A. Tarmian, M. Jawaid, 2015, Thermal and biodegradation properties of poly (lactic acid)/fertilizer/oil palm fibers blends biocomposites, Polymer Composites vol. 36 no. 3, pp. 576-583. F. Hernández-Carmona, Y. Morales-Matos, H. Lambis-Miranda, J. Pasqualino, 2017, Starch extraction potential from plantain peel wastes, Journal of Environmental Chemical Engineering vol. 5 no.5, pp. 4980-4985. K.L.G. Ho, A.L. Pometto III, Temperature Effects on Soil Mineralization of Polylactic Acid Plastic in Laboratory Respirometers, Journal of environmental polymer degradation 7 (1999) 101-108. S.K. Hosseinihashemi, F. Arwinfar, A. Najafi, G. Nemli, N. Ayrilmis, 2016, Long-term water absorption behavior of thermoplastic composites produced with thermally treated wood, Measurement vol. 86, pp. 202-208. R.C. Imbachi‐Hoyos, M.d.R. Salazar‐Sánchez, J.F. Solanilla‐Duque, 2022, Study of morphological, structural, and thermal changes of biodegradable material in simulated natural environmental conditions, Environmental Quality Management vol. 32 no. 1, pp. 365-378. L. Javazmi, A. Young, G.J. Ash, T. Low, Kinetics of slow release of nitrogen fertiliser from multi-layered nanofibrous structures, Scientific Reports 11 (2021) 1-8. Y. Jin, F. Cai, C. Song, G. Liu, C. Chen, 2022, Degradation of biodegradable plastics by anaerobic digestion: Morphological, micro-structural changes and microbial community dynamics, Science of The Total Environment vol. 834, 155167. M.R. Ketabchi, M. Khalid, C.T. Ratnam, S. Manickam, R. Walvekar, M.E. Hoque, 2016, Sonosynthesis of cellulose nanoparticles (CNP) from kenaf fiber: Effects of processing parameters, Fibers and Polymers vol. 17, pp. 1352-1358. J. Kovács, T. Tabi, 2011, Examination of starch preprocess drying and water absorption of injection‐molded starch‐filled poly (lactic acid) products, Polymer Engineering & Science vol. 51 no. 5, pp. 843-850. A.J. Lasprilla, G.A. Martinez, B.H. Lunelli, A.L. Jardini, R. Maciel Filho, 2012, Poly-lactic acid synthesis for application in biomedical devices — A review, Biotechnology Advances vol, 30, pp. 321-328. B. Liu, T. Guan, G. Wu, Y. Fu, Y. Weng, 2022, Biodegradation behavior of degradable mulch with poly (butylene adipate-co-terephthalate)(PBAT) and poly (butylene succinate) (PBS) in simulation marine environment, Polymers vol.14 no. 8, 1515. J. Lunt, 1998, Large-scale production, properties and commercial applications of polylactic acid polymers, Polymer Degradation and Stability vol. 59 no. 1-3, pp. 145-152. P. Malathi, K. Sellamuthu, K. Sivakumar, 2021, Nutrient encapsulation for enhancing yield and sustaining soil health, Biotica Research Today vol. 3, 1155-1157. S. Nanda, B.R. Patra, R. Patel, J. Bakos, A.K. Dalai, 2021, Innovations in applications and prospects of bioplastics and biopolymers: A review, Environmental Chemistry Letters vol. 20, pp. 379-395. S. Notaro, E. Lovera, A. Paletto, Consumers’ preferences for bioplastic products: A discrete choice experiment with a focus on purchase drivers, 2022, Journal of Cleaner Production vol. 330, 129870. J.R.A. Pires, V.G.L. Souza, P. Fuciños, L. Pastrana, A.L. Fernando, Methodologies to assess the biodegradability of bio-based Polymers — Current knowledge and existing gaps, Polymers 14 (2022) 1359. D.C. Rego, H.L. Corrêa, 2022, Biopolymers applied to packaging: A brief literature review on their impact on sustainability, vol. 4 no. 2, pp. 4-14. N.N. Rohidi, S.A. Othman, Properties of irradiated bioplastic - A review, Proceedings of the 3rd International Conference on Green Environmental Engineering and Technology, Springer, 2022, pp. 161-169. N.A. Rosli, M. Karamanlioglu, H. Kargarzadeh, I. Ahmad, 2021, Comprehensive exploration of natural degradation of poly (lactic acid) blends in various degradation media: A review, International journal of biological macromolecules vol. 187, pp. 732-741. D. Seshikala, M.S. Charya, 2012, Collection and screening of Basidiomycetes for better lignin degraders, International Journal of Life Sciences Biotechnology and Pharma Research vol. 4 no. 1, pp. 203-211. S. Sharma, A. Majumdar, B.S. Butola, 2021, Tailoring the biodegradability of polylactic acid (PLA) based films and ramie-PLA green composites by using selective additives, International Journal of Biological Macromolecules vol. 181, pp. 1092-1103. R. Shogren, W. Doane, D. Garlotta, J. Lawton, J. Willett, 2003, Biodegradation of starch/polylactic acid/poly (hydroxyester-ether) composite bars in soil, Polymer Degradation and Stability vol. 79 no. 3, pp. 405-411. B.X. Sun, C.Z. Chuai, S. Luo, Y. Guo, X.Q. Feng, 2022, Biodegradability of poly (butylene succinate) under enzymatic degradation, Advanced Materials Research vol. 750-752, pp. 1318-1321. N.A.A.B. Taib, M.R. Rahman, D. Huda, K.K. Kuok, S. Hamdan, M.K.B. Bakri, M.R.M.B. Julaihi, A. Khan, 2022, A review on poly lactic acid (PLA) as a biodegradable polymer, Polymer Bulletin vol. 80, pp. 1179-1213. S. Teixeira, K.M. Eblagon, F. Miranda, M.F. R. Pereira, J.L. Figueiredo, 2021, Towards controlled degradation of poly (lactic) acid in technical applications, C: Journal of Carbon Research vol. 7 no. 2, 42. N. Tripathi, M. Misra, A.K. Mohanty, 2021, Durable polylactic acid (PLA)-based sustainable engineered blends and biocomposites: Recent developments, challenges, and opportunities, ACS Engineering Au vol. 1 no. 1, pp. 7-38. H. Urayama, T. Kanamori, Y. Kimura, 2002, Properties and biodegradability of polymer blends of poly(L-lactide)s with different optical purity of the lactate units, Macromolecular Materials and Engineering vol. 287 no. 2, pp. 116-121. R.A. Wilkes, L. Aristilde, 2017, Degradation and metabolism of synthetic plastics and associated products by Pseudomonas sp.: capabilities and challenges, Journal of applied microbiology vol. 123 no. 3, pp. 582-593. C.S. Wu, 2005, Improving polylactide/starch biocomposites by grafting polylactide with acrylic acid–characterization and biodegradability assessment, Macromolecular Bioscience vol. 5 no. 4, pp. 352-361. S.S. Zamir, B. Fathi, A. Ajji, M. Robert, S. Elkoun, 2022, Biodegradation of modified starch/poly lactic acid nanocomposite in soil, Polymer Degradation and Stability vol. 199, 109902. Cite Share Download PDF Status: Published Journal Publication published 29 Jul, 2023 Read the published version in Environmental Science and Pollution Research → Version 1 posted Editorial decision: Major Revision 25 Jun, 2023 Reviewers agreed at journal 12 Jun, 2023 Reviewers invited by journal 11 Jun, 2023 Editor invited by journal 09 Jun, 2023 Editor assigned by journal 30 May, 2023 First submitted to journal 24 May, 2023 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-2928168","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":208728602,"identity":"d11408e7-6fff-40da-9635-4ef5a72b7834","order_by":0,"name":"Mohammed Reza Ketabchi","email":"","orcid":"","institution":": University of Nottingham Malaysia Faculty of Engineering","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Mohammed","middleName":"Reza","lastName":"Ketabchi","suffix":""},{"id":208728603,"identity":"0a9c8673-e079-4256-b522-4c87a92fdcc1","order_by":1,"name":"Salman Masoudi Soltani","email":"","orcid":"","institution":"Brunel University London","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Salman","middleName":"Masoudi","lastName":"Soltani","suffix":""},{"id":208728604,"identity":"cd80cc21-9011-4b0a-8ed5-24c4da8d37c9","order_by":2,"name":"Andy Chan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyklEQVRIiWNgGAWjYHACNiD+JwfnShCp5YAx6VoSG4jWwt/A/OzBzx130rf3rzFg+FHDkDizgYAWiQNs5oa9Z57lzrnxxoCx5xhD4myCzjrAwybB28acO0PijAEDbwND4jxCOuSBWiT/tjGnSwC1MP4lRosBUIs0b9vhBAn+HgNmkC0EHWZ4mM1MWrYtzXCGBFvBYZljEsYEvS93vPmZ5Ns2G3kJ/sMbH76psZGdcYCQNcwwhkQCwwHiIhIO+AmaPgpGwSgYBSMVAAA6iTrfS9dw+QAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-2267-4949","institution":"Robert Gordon University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Andy","middleName":"","lastName":"Chan","suffix":""}],"badges":[],"createdAt":"2023-05-12 14:47:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2928168/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2928168/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11356-023-28892-0","type":"published","date":"2023-07-29T21:45:39+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":38538279,"identity":"fc3533ce-f610-4dc9-ac1d-af2b497121bd","added_by":"auto","created_at":"2023-06-14 14:08:36","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":38616,"visible":true,"origin":"","legend":"\u003cp\u003eWeight loss% of the biocomposites in the soil test with respect to time\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2928168/v1/e1e70b689a89af413944fe20.jpg"},{"id":38539663,"identity":"fa5f7378-2616-4f41-8941-9a9970ffbc41","added_by":"auto","created_at":"2023-06-14 14:16:36","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":51264,"visible":true,"origin":"","legend":"\u003cp\u003eWater uptake as a function of exposure time in distilled water\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2928168/v1/3f585c65a34ad964417dbdf0.jpg"},{"id":38538283,"identity":"dcd76c1c-4dcc-4605-b4c8-28dffe336140","added_by":"auto","created_at":"2023-06-14 14:08:37","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":88033,"visible":true,"origin":"","legend":"\u003cp\u003eThermogravimetric analyses: PLA and the biocomposites\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2928168/v1/30866a078acbc2ac85b6b53b.jpg"},{"id":38539665,"identity":"755edf26-6bbe-4a8e-b23b-9cc73e85ed70","added_by":"auto","created_at":"2023-06-14 14:16:37","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":38916,"visible":true,"origin":"","legend":"\u003cp\u003eThermogravimetric analyses of the biodegraded biocomposites; (a) PN, (b) PR, (c) PNR\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2928168/v1/e2b9ad2fd942c100f297cb74.jpg"},{"id":38539664,"identity":"11ab1060-1583-417c-9048-932a8ca8388d","added_by":"auto","created_at":"2023-06-14 14:16:37","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":113408,"visible":true,"origin":"","legend":"\u003cp\u003eScanning electron micrographs after 2160 h of soil burial; (a) PLA, (b) PNR, (c) PN1, (d) PN2, (e) PR2, (f) PR3\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2928168/v1/187eeb353f7b354787a65781.jpg"},{"id":44734173,"identity":"d7bbc670-8560-4a27-83c3-f29e9efafa93","added_by":"auto","created_at":"2023-10-16 22:15:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":600075,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2928168/v1/deeb61ee-39a0-4199-bac1-85fb52eaf8de.pdf"}],"financialInterests":"","formattedTitle":"\u003cp\u003eSynthesis of a New Biocomposite for Fertiliser Coating: Assessment of \u003cem\u003eBiodegradability\u003c/em\u003eand \u003cem\u003eThermal Stability\u003c/em\u003e\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eBiodegradable materials are increasingly becoming popular - owing to their inherently safer disposal pathways. Many industries including packaging, biomedical, pharmaceutical, agricultural and horticultural, textile, household goods and automotive have been integrating the use of biodegradable materials into their end products [Nanda et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2021\u003c/span\u003e, Imbachi-Hoyos et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. According to the USA Biodegradable Products Institute (BPI) standards, biomaterials are classed as those which must disintegrate within 3-month (2160 h) of their production [Briassoulis et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2010\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDegradation involves fragmentation and changes in the molecular arrangements of materials. There are different types of degradation \u003cem\u003ee.g.\u003c/em\u003e thermal degradation, thermos-oxidative degradation, direct and indirect photo-degradation, irradiation degradation, mechano-chemical degradation, chemical degradation and biodegradation [Teixeira et al. \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2021\u003c/span\u003e, Rohidi \u0026amp; Othman \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2022\u003c/span\u003e, Pires et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. The degradation of biodegradable materials disposes various organic resources which could benefit the soil. During the natural degradation process (biodegradation), the process begins with photodegradation by UV light from the sun and the organic constituents are oxidised and converted to ecologically accepted molecules including minerals, water and carbon dioxide [Chellasamy et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. According to the EN-13432 European standard, in the absence of oxygen, these biomaterials decompose into minerals, carbon dioxide and methane [Notaro et al. 2022]. These soil-friendly features have gained considerable attention among agricultural sectors. Biocomposites have both directly and indirectly (as a carrier) shown their applicability in the improvement of soil properties in several distinct ways [Akhir \u0026amp; Mustapha \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2022\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFarmers have been using fertilisers for many decades to improve soil properties for enhanced cultivation. Fertilisers contain hydrophilic minerals and salts. Fast dissolution of these salts causes irrecoverable damages to both soil and plants\u0026rsquo; nutrients\u0026rsquo; uptake. To control the dissolution process, various methods have been investigated. One method is introduction of compounds with low water solubility and low volatility to slow down the dissolution process [Barra Caracciolo \u0026amp; Grenni \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. Through this method, the synthesised compounds release the nutrients over longer periods of time (slow release). This can be costly in practice, depending on the soil condition (temperature, oxygen level, pH) and plant\u0026rsquo;s needs [Malathi et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2021\u003c/span\u003e]. An alternative method to overcome this, is to encapsulate the actual fertiliser with organic compounds capable of progressively releasing the nutrients following its biodegradation in soil [Angelo et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2021\u003c/span\u003e, Javazmi et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2021\u003c/span\u003e]. This results in gradual release of the nutrients synced with the continual biodegradation process. Depending on the target application, the biodegradation can be further tuned by adjusting the capsule thickness or employing more/less rigid compositions. This, in return, builds on more confidence in commercial viability of such biocomposites [Tripathi et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2021\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eBiopolymers are extracted from natural resources such as corn, potato and sugarcane [Rego \u0026amp; Corr\u0026ecirc;a \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. They have become an alternative to petroleum-based plastics following their global availability and the facile cultivation of natural resources. Through different agricultural environments, plants are cultivated, harvested and then chemically and physically treated to extract their starch content. The isolated starch is then refined using special enzymes to produce a specific biopolymer [Lasprilla et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2012\u003c/span\u003e, Apriyanto et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. This product is fully biodegradable into mainly water and carbon dioxide. Biodegradable polymers are either plant- and bacterial-based or synthesised using a bio-based monomer. Polylactic acid (PLA) is a synthesised biopolymer comprising lactic acid monomers [Ahmad et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. However, poor thermal and mechanical performance and also high production costs are the key drawbacks in large-scale applications of the PLA [Taib et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2022\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePLA has been reported to be well biodegradable; however, it suffers from low degradation rates when compared to other aliphatic biopolymers [Rosli et al. \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2021\u003c/span\u003e]. In the early stages of PLA degradation, the PLA chains with high molecular weight (ester bonds) are hydrolysed to form lower molecular weight chains [Fukushima et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2012\u003c/span\u003e]. Amorphous regions provide higher hydrolysis rate compared to the crystalline counterparts [Sun et al 2013]. An increase in the biodegradation rate was observed following reinforcement of PLA with starch (an inherently amorphous material) which was ascribed to moisture absorption which benefits the hydrolysis process [Wu \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2005\u003c/span\u003e, Hern\u0026aacute;ndez-Carmona 2017]. On the other hand, an increase in the PLA crystallinity was reported to decrease its biodegradation rate [Urayama et al. \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2002\u003c/span\u003e, Shogren et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2003\u003c/span\u003e]. The introduction of a basic or an acidic solution to the soil, and an elevation in both the temperature and the humidity were found to facilitate these reactions [Avinc et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2010\u003c/span\u003e]. Degradation and mineralisation of the PLA has been stated to complete in 6480 h (9 months) and 84 h at 30\u0026deg;C and 70\u0026deg;C, respectively [Lunt \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e1998\u003c/span\u003e]. The biodegradation rate of the PLA plastic films in soil was reported at 28 mg in 24 h at 28\u0026deg;C with 27% conversation to CO\u003csub\u003e2\u003c/sub\u003e [Ho \u0026amp; Pometto \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e1999\u003c/span\u003e]. Higher degradation rates were observed at the sample core due to the high concentration of carboxylic acid groups which enhance the ester hydrolysis [Harmaen et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2015\u003c/span\u003e]. Meanwhile, bacterial and fungal microbes can act as a catalyser [Wilkes \u0026amp; Aristilde \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2017\u003c/span\u003e]. Such microorganisms (polysaccharide utilisers) break ester bonds to an acid or an alcohol, which then form low-molecular-weight chains which in the end, convert into CO\u003csub\u003e2\u003c/sub\u003e, water and humus [Seshikala \u0026amp; Charya \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2012\u003c/span\u003e]. Development of fungal mycelia on the PLA surface was reported after 8 weeks in soil [Shogren et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2003\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this study, a new biocomposite was prepared as an encapsulating material for fertilisers. The biodegradation and water absorption behaviour of the synthesised biocomposite was determined (ASTM D256) and a polynomial model was developed.\u003c/p\u003e"},{"header":"2. Experimental procedures","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Materials\u003c/h2\u003e \u003cp\u003ePolylactic acid (Ingeo biopolymer) (grade 2003 D, melt index: 6 g/10 min, density: 1.22 g/cm\u003csup\u003e3\u003c/sup\u003e) was supplied by Nature Works LLC product, USA. The granules were dried at 60\u0026deg;C for 12 h prior to the compounding process. Synthetic liquid polyisoprene (LIR-30) (Molecular weight: 28000, Tg: -63\u0026deg;C by Kuraray Co. Ltd., Japan) was used as the natural rubber (NR). Cellulose nanoparticles (CNP) were extracted from kenaf fibre according to the optimised process obtained through our earlier study [Ketabchi et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2016\u003c/span\u003e]. The soil in this study was collected from the central Malaysian palm oil forests based in the University of Nottingham Malaysia. The soil had a pH of 6.5 (1:2 soil and water suspension) and did not contain any composting materials and showed no enzymatic activity.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Methods\u003c/h2\u003e \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e \u003ch2\u003e2.2.1 Compounding process\u003c/h2\u003e \u003cp\u003eNine different sets of compositions were prepared \u003cem\u003evia\u003c/em\u003e melt compounding, followed by injection moulding (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). All biocomposites were prepared using a Brabender PL2000-6 twin-screw compounder (180\u0026deg;C, 10 min and 100 rpm). All compounds were then moulded using a bench-top injection moulding machine (RR3400, RAY-RAN Injection Moulding Machine) at 180\u0026deg;C and 90\u0026deg;C for barrel and mould temperatures, respectively. Holding time was set at 8 seconds in accordance with the ASTM D256 method.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe compositions of the prepared samples\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePLA content\u003c/p\u003e \u003cp\u003e(wt. %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCNP content\u003c/p\u003e \u003cp\u003e(wt. %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNR content\u003c/p\u003e \u003cp\u003e(wt. %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePLA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePN1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePN2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePN3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePR1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePR2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePR3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePR4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePNR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.2.2 Biodegradation test\u003c/h2\u003e \u003cp\u003eThe biodegradation process of the PLA-based biocomposites was carried out in a natural-soil environment, using accessible tools and materials [Harmaen et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2015\u003c/span\u003e]. The soil was free from any enzymatic activities and any compositing additive. Nine plastic containers (250 ml) were filled with identical amounts of soil samples (labelled according to Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The biocomposite samples (~\u0026thinsp;30 \u0026times; 10\u0026times; 3 mm) were then placed (buried) into each of the nine containers. The containers were next kept at room temperature (28\u0026deg;C) and with an ambient relative humidity of 80%. The experiment was continuously run for 2160 h. The biocomposites were subsequently weighed using a lab-scale balance. The change in the biocomposites\u0026rsquo; masses was determined after 6, 12, 24, 48, 72, 96, 120, 1440, 1680, 1920, 2160 h after their initial burial in soil samples. Prior to any analysis, each biocomposite was first rinsed under tab water to wash out the soil residues and later dried at 80\u0026deg;C to fully remove the moisture until a constant dry weight was achieved. The initial (\u003cem\u003ei.e.\u003c/em\u003e before test) and the secondary (\u003cem\u003ei.e.\u003c/em\u003e after x hours) sample weights were recorded and labelled as S\u003csub\u003e0\u003c/sub\u003e and S\u003csub\u003e1\u003c/sub\u003e, respectively. The weight loss percentage was calculated using Eq.\u0026nbsp;1:\u003c/p\u003e \u003cp\u003eWeight loss (%) = \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{\\text{S}0 - \\text{S}1}{\\text{S}0 }\\text{*} 100\\)\u003c/span\u003e\u003c/span\u003e \u003cb\u003eEq.\u0026nbsp;(1)\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.2.3 Water absorption test\u003c/h2\u003e \u003cp\u003eThe test was done according to the ASTM D 570 [Hosseinihashemi et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2016\u003c/span\u003e]. Plastic containers were used and filled with distilled water. The containers were kept at room condition (28\u0026deg;C, 80% humidity). The water level was maintained the same throughout the entire test run. The biocomposites were weighed initially and after 6, 12, 24, 48, 72, 96, 120, 1440, 1680, 1920, 2160 h of soaking in distilled water. Prior to each analysis, biocomposites were moderately dried using a towel to remove the excess water on the surface until a constant weight was obtained. The primary (before test) and secondary (after x hours) weights of the samples were recorded and labelled as W\u003csub\u003e0\u003c/sub\u003e and W\u003csub\u003e1\u003c/sub\u003e, respectively. The water absorption percentage was calculated using Eq.\u0026nbsp;2:\u003c/p\u003e \u003cp\u003eWater absorption (%) = \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{\\text{W}0 - \\text{W}1}{\\text{W}0}\\text{*}100\\)\u003c/span\u003e\u003c/span\u003e \u003cb\u003eEq.\u0026nbsp;(2)\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e2.2.4 Thermogravimetric analyses (TGA)\u003c/h2\u003e \u003cp\u003eBoth of the non-biodegraded and biodegraded samples were used to determine the influence of biodegradation on the thermal stability of the biocomposites. Perkin Elmer simultaneous thermal analyser (STA 6000, USA) was used to run the themo-gravimetric analyses (nitrogen flow rate: 10 ml/min, temperature starting from 30\u0026deg;C to 500\u0026deg;C, a heating rate of 10\u0026deg;C/min.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.2.5 Scanning electron microscopy (SEM)\u003c/h2\u003e \u003cp\u003eBiocomposites were recovered from soil after 2160 h of burial and their surface structure was analysed using a scanning electron microscope (FEI QUANTA 400F) at 20 kV. The surface morphologies were studied and compared with the un-buried biocomposite samples.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Biodegradation in soil\u003c/h2\u003e \u003cp\u003eThe results show that the biocomposites lose their weight by 0.61\u0026ndash;3.70% (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Within the first 720 h of the burial in soil, the biocomposites were only slightly decomposed. Within the same test period, the weight of the PN2, PN3, PR1, PR4 and PNR increased by only 0.6%. This is associated with water uptake from the soil. A weight loss of just 0.61\u0026ndash;2.08% was observed at the very early stage of the degradation process (\u003cem\u003ei.e.\u003c/em\u003e after 1440 h). The biodegradation process was more noticeable after 2160 h of burial where CNP/PLA biocomposites underwent a weight loss of ~\u0026thinsp;3%. However, the NR/PLA biocomposites lost their weight by about 1.5%. Basically, a higher CNP and a lower NR content resulted in a faster biodegradation process. Consequently, the PN3 corresponded to the fastest observed biodegradation process. This is linked to the amorphous regions present in CNP which favourably affects the biocomposites\u0026rsquo; resistance against degradation. CNP contains both crystalline and amorphous regions; however, a dominant crystalline region was detected as a result of the experimental conditions. Fair biodegradation of the biocomposites with CNP confirms the fact that amorphous structures are more easily attacked by hydrolytic enzymes which can result in much higher biodegradation rates [Liu et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. This suggests the significant role of the amorphous regions in the biodegradation processes. Depending on the applications, further CNP treatment can be considered in order to tailor-make the degree of crystallinity.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe decomposition of the PR4 was slower than that of any other studied biocomposites. This is associated with the hydrophobic nature of the NR which retains the PLA structure. Similar trend was also observed with the PNR which was linked not only to the nature of the NR but also to the enhanced interfacial adhesion between the PLA matrix and the CNP due to the addition of the NR. Therefore, the PNR composition exhibited a moderate degradation phase as compared to both the CNP/PLA and the NR/PLA biocomposites. The PNR showed a weight loss of 1.3% after 2160 h of the initial burial.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Water absorption\u003c/h2\u003e \u003cp\u003eWater absorption test was carried out in parallel with the soil burial test (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). During the first 72 h of the test, most of the samples appeared to absorb only little amount of water. However, the PR4 and PNR samples began a considerable water absorption after 12 h. They both demonstrated the highest water uptake during the test: 3.14% for PR4 and 4.34% for PNR after 2160 h. The biocomposites with CNP had relatively lower water absorption rates as compared to the biocomposites with NR. This is linked to the strong crystalline structure of CNP and the preparation technique, minimising the hydrophilic nature of the fibre. Therefore, an increase in the CNP content shows a minor impact on the water absorption rate. On the other hand, an increase in the NR content, elevates water uptake. This is linked to the excess amount of NR in the PR4 which results in the formation of micro bubbles and voids in the sample. The performance of composite materials is highly dependent on the presence of pores as they influence the heat and mass transfer behaviour [Hosseinihashemi et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2016\u003c/span\u003e]. Most of the biocomposites showed a maximum water absorption of about 1% after 2160 h (expect for the PR4 and PNR). The PN2 and PR3 were associated with the lowest water absorption rates. This reveals that a combination of CNP (3 wt. %) and NR (15%) is the optimum amount of reinforcement in order to minimise the PLA\u0026rsquo;s water absorption.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Thermal degradation\u003c/h2\u003e \u003cp\u003eThe thermal stability of the biocomposites was analysed \u003cem\u003evia\u003c/em\u003e TGA analyses. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e illustrates the weight loss during the TGA test. All biocomposites began to degrade at about 320\u0026deg;C. At this temperature, the PN1 and PN2 both showed an 8% weight loss while the PN3 underwent a 5% weight loss. This trend became more noticeable at temperatures\u0026thinsp;\u0026gt;\u0026thinsp;360\u0026deg;C. At this temperature, the PN1 showed a 70% weight loss compared to a 55% and a 48% weight loss for the PN2 and PN3, respectively. This reveals the effect of CNP on the thermal stability of the PLA at high temperatures. Meanwhile, the biocomposites with NR showed an opposite behaviour compared to the biocomposites with CNP.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eHigher concentrations of NR (\u0026gt;\u0026thinsp;10 wt. %) adversely impacts the thermal stability of the PLA. The excess NR was located between the PLA granules \u003cem\u003ei.e.\u003c/em\u003e creating a gap between the granules, which in turn, affects the overall stability of the PR3 and PR4 at higher temperatures. Compared to NR, at such elevated temperatures, weight loss is mainly associated with the degradation of the cellulose fibres. Therefore, the PR2 shows the highest thermal stability among the biocomposites. The thermal studies together with the soil burial and water absorption tests successfully pinpointed the optimum PNR compositions (\u003cem\u003ei.e.\u003c/em\u003e 3 wt. % CNP and 10 wt. % NR). The reinforcement of PLA with both NR and CNP improved the thermal stability by almost 20\u0026deg;C.\u003c/p\u003e \u003cp\u003eTo further study the effect of biodegradation on the thermal stability of the biocomposites, three biodegraded samples were tested (tagged as PN\u0026rsquo; (biodegraded PN), PR2\u0026rsquo; (biodegraded PR2) and PNR\u0026rsquo; (biodegraded PR2)). Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e presents the thermal behaviour of the biodegraded samples for temperatures between 30\u0026deg;C and 450\u0026deg;C. The PN\u0026rsquo; showed a higher thermal stability than the PN which is linked to the stability of cellulose. On the other hand, the PR showed a higher thermal stability than the PR\u0026rsquo; which is associated with the biodegradation and the poor thermal stability of NR. At 360\u0026deg;C, the PN, PN\u0026rsquo;, PR2, and PR2\u0026rsquo; lost about 40, 55, 28 and 40% of their total mass, respectively. The PNR and PNR\u0026rsquo; demonstrated very similar thermal behaviour, indicating the thermal stability of the PNR despite the structural changes brought about by the biodegradation process. This is especially suitable in biodegradation applications deployed in tropical and/or hot countries \u003cem\u003ee.g.\u003c/em\u003e Malaysia.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e3.4. Morphological analyses\u003c/h2\u003e \u003cp\u003eThe effect of biodegradation on the surface of the biocomposites after 2160 h of burial in soil was analysed using SEM micrographs (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Partial biodegradation of the PLA granules was observed which was due to microbial action rather than physical discharge [Shogren et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2003\u003c/span\u003e]. The presence of the cracks and holes confirmed the biodegradation process [Brzeska et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. A greater number of cracks was observed on the biocomposites with higher rates of biodegradation (\u003cem\u003ei.e.\u003c/em\u003e PLA, PN3, and PR3). In addition to the cracks, the shrinkage of the biocomposites also facilitates the exposure of the CNP to moisture and its surrounding area [Harmaen et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2015\u003c/span\u003e]. Due to the reinforcement, compared to the PLA, fewer number of cracks were observed on the PNR surface resulting in a reduction in the biodegradation rate. The PNR is an appropriate fertiliser encapsulating material due to its suitable biodegradation process. Moderate biodegradation of the PNR can also stabilise and control the release of the fertiliser nutrients in soil.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e3.5. Rate of biodegradation and water absorption\u003c/h2\u003e \u003cp\u003eAs a fertiliser encapsulating material, it is critical to determine the time required for complete the biodegradation of the PNR and the corresponding water absorption rate. The soil burial and the water absorption test results were best fitted to a cubic polynomial model (Eq.\u0026nbsp;3), where Y is \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{weight loss\\%}{water absorption\\%}\\)\u003c/span\u003e\u003c/span\u003e; X is the time factor; Y\u003csub\u003e0\u003c/sub\u003e, a, b and c are the four coefficients used in the cubic model. The applicability of the polynomial model was examined by assessing the regression coefficient (R\u003csup\u003e2\u003c/sup\u003e). The results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cem\u003eY\u0026thinsp;=\u0026thinsp;Y\u003c/em\u003e \u003csub\u003e \u003cem\u003e0\u003c/em\u003e \u003c/sub\u003e\u0026thinsp;\u003cem\u003e+\u0026thinsp;aX\u0026thinsp;+\u0026thinsp;bX\u003c/em\u003e \u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e+ cX\u003c/em\u003e\u003csup\u003e\u003cem\u003e3\u003c/em\u003e\u003c/sup\u003e \u003cb\u003eEq.\u0026nbsp;(3)\u003c/b\u003e\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of the cubic polynomial regression model for the soil burial test\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTest type\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBiocomposite\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eY\u003csub\u003e0\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSoil\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePNR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.0045\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.0000052\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.0000000013\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePLA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.028\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.0019\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.0000032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.00000000078\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWater\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePNR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.190\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0096\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e-0.0000083\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0000000021\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.81\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePLA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.089\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.00028\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.00000099\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.00000000041\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.79\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIt is found that almost 3062 and 3863 h of soil burial is required for complete (\u003cem\u003ei.e.\u003c/em\u003e 100%) biodegradation of the PNR and PLA, respectively. The biodegradation process is considered \u003cem\u003efast\u003c/em\u003e as compared to similar studies reported in the literature [Jin et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2022\u003c/span\u003e, 37, Sharma et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2021\u003c/span\u003e]. This was directly linked to the test conditions (\u003cem\u003ei.e.\u003c/em\u003e high humidity). The biodegradation rates of the PNR and PLA were measured to be about 0.15% and 0.03% per hour, respectively. In other words, the PNR, as a encapsulating material, can last for nearly 3072 h under tropical conditions, boasting a moderate biodegradation rate of about 0.15%/h. The water absorption rate was measured to be 1.2%/h and 0.08%/h for the PNR and PLA, respectively. Slightly higher biodegradation and water absorption rates are linked to the presence of the amorphous regions [Kov\u0026aacute;c \u0026amp; Tabi 2011, Dogu \u0026amp; Kaynak \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2016\u003c/span\u003e, Zamir et al. \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2022\u003c/span\u003e]. It was understood that the CNP accelerates while the NR moderates the biodegradation of the PLA biocomposites. This is a further confirmation of the optimum composition used in the PNR biocomposites.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eIn this study, indoor biodegradation, thermal degradation and water absorption processes for PNR biocomposites were investigated. The results were best described by a cubic polynomial model. The PNR biocomposites were observed to be biodegradable under natural conditions. Cracks and shrinkage in the biocomposites\u0026rsquo; surfaces accelerated the exposure of the CNP to moisture and its environment. Amorphous regions in CNP were realised to play a key role in accelerating the PNR biodegradation. An increase in the biodegradation rate was also linked to the test conditions (\u003cem\u003ei.e.\u003c/em\u003e high humidity). The CNP accelerated while the NR moderated the biodegradation rate of the PNR biocomposites. The PNR demonstrated an acceptable water resistance when prepared with the optimum compositions. A composition comprising 3 wt. % CNP and 15 wt. % NR was observed to be the optimum amount of reinforcement in order to minimise the PLA\u0026rsquo;s water adsorption. An excess amount of NR in the PR4 biocomposites affected its morphology and led to a higher water absorption capacity. An improvement in the PLA thermal stability was achieved following the integration of both the CNP and NR. Labour and application costs may be reduced by using PNR as a fertiliser encapsulating material by eliminating the need for multiple fertilizer applications. Prolonged nutrient release may provide more uniform plant nutrition, better growth and improved plant performance. Master-batch preparation of the PNR/fertiliser is therefore, of great importance in future studies and investigations. The future studies include analysing the interaction between PNR/fertiliser master-batch and soil.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgment\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to specially thank Dr Chantara Thevy Ratnam and Dr Mohammad Khalid for their assistance and input in this work. We would also like to acknowledge the University of Nottingham Malaysia for providing us with the research facilities to conduct this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eNot applicable\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eNot applicable\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Publish\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAll authors agree to publish their research data pertinent to the paper.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u0026ldquo;The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u0026rdquo;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u0026ldquo;The authors have no relevant financial or non-financial interests to disclose.\u0026rdquo;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u0026ldquo;All authors contributed equally to the study conception and design. Material preparation, data collection and analysis were performed by Mohammad Mohammad Reza Ketabchi, Salman Masoudi Soltani and Andy Chan. The first draft of the manuscript was written by Reza Ketabchi and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u0026rdquo;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Data and Materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u0026ldquo;All data, raw and analysed, have been stored in the university repository and are available upon request. \u0026nbsp;They are not made public due to contractual agreement.\u0026nbsp;\u003c/em\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eA. Ahmad, F. Banat, H. Alsafar, S.W. Hasan, 2022, An overview of biodegradable poly (lactic acid) production from fermentative lactic acid for biomedical and bioplastic applications, Biomass Conversion and Biorefinery (in press).\u003c/li\u003e\n\u003cli\u003eM.A.M. Akhir, M. Mustapha, 2022 Formulation of biodegradable plastic mulch film for agriculture crop protection: A review, Polymer Reviews (2022) 1-29.\u003c/li\u003e\n\u003cli\u003eL.M. Angelo, D. Fran\u0026ccedil;a, R. Faez, 2021, Biodegradation and viability of chitosan-based microencapsulated fertilizers, Carbohydrate Polymers vol. 257, 117635.\u003c/li\u003e\n\u003cli\u003eA. Apriyanto, J. Compart, J. Fettke, 2022, A review of starch, a unique biopolymer\u0026ndash;structure, metabolism and in planta modifications, Plant Science vol. 318, 111223.\u003c/li\u003e\n\u003cli\u003eO. Avinc, M. Wilding, D. Phillips, D. Farrington, 2010, Investigation of the influence of different commercial softeners on the stability of poly(lactic acid) fabrics during storage, Polymer Degradation and Stability vol. 95 no. 2, pp. 214-224.\u003c/li\u003e\n\u003cli\u003eA. Barra Caracciolo, P. Grenni, 2022, Bioremediation of soil ecosystems from triazine herbicides, pesticides in soils: Occurrence, fate, control and remediation, The Handbook of Environmental Chemistry, pp. 353-377.\u003c/li\u003e\n\u003cli\u003eJ. Brzeska, G. Jasik, W. Sikorska, B. Mendrek, J. Karczewski, M. Kowalczuk, M. Rutkowska, 2022, Susceptibility to degradation in soil of branched polyesterurethane blends with polylactide and starch, Polymers vol. 14, 2086.\u003c/li\u003e\n\u003cli\u003eD. Briassoulis, C. Dejean, P. Picuno, 2010, Critical review of norms and standards for biodegradable agricultural plastics Part II: Composting, Journal of Polymers and the Environment vol. 18, pp. 364-383.\u003c/li\u003e\n\u003cli\u003eG. Chellasamy, R.M. Kiriyanthan, T. Maharajan, A. Radha, K. Yun, 2022, Remediation of microplastics using bionanomaterials: A review, Environmental Research vol. 208, 112724.\u003c/li\u003e\n\u003cli\u003eB. Dogu, C. Kaynak, 2016, Behavior of polylactide/microcrystalline cellulose biocomposites: effects of filler content and interfacial compatibilization, Cellulose vol. 23, pp. 611-622.\u003c/li\u003e\n\u003cli\u003eK. Fukushima, E. Gim\u0026eacute;nez, L. Cabedo, J. Lagar\u0026oacute;n, J.L. Feijoo, 2012, Biotic degradation of poly (DL-lactide) based nanocomposites, Polymer degradation and stability vol. 97 no. 8, pp. 1278-1284.\u003c/li\u003e\n\u003cli\u003eA.S. Harmaen, A. Khalina, I. Azowa, M.A. Hassan, A. Tarmian, M. Jawaid, 2015, Thermal and biodegradation properties of poly (lactic acid)/fertilizer/oil palm fibers blends biocomposites, Polymer Composites vol. 36 no. 3, pp. 576-583.\u003c/li\u003e\n\u003cli\u003eF. Hern\u0026aacute;ndez-Carmona, Y. Morales-Matos, H. Lambis-Miranda, J. Pasqualino, 2017, Starch extraction potential from plantain peel wastes, Journal of Environmental Chemical Engineering vol. 5 no.5, pp. 4980-4985.\u003c/li\u003e\n\u003cli\u003eK.L.G. Ho, A.L. Pometto III, Temperature Effects on Soil Mineralization of Polylactic Acid Plastic in Laboratory Respirometers, Journal of environmental polymer degradation 7 (1999) 101-108.\u003c/li\u003e\n\u003cli\u003eS.K. Hosseinihashemi, F. Arwinfar, A. Najafi, G. Nemli, N. Ayrilmis, 2016, Long-term water absorption behavior of thermoplastic composites produced with thermally treated wood, Measurement vol. 86, pp. 202-208.\u003c/li\u003e\n\u003cli\u003eR.C. Imbachi‐Hoyos, M.d.R. Salazar‐S\u0026aacute;nchez, J.F. Solanilla‐Duque, 2022, Study of morphological, structural, and thermal changes of biodegradable material in simulated natural environmental conditions, Environmental Quality Management vol. 32 no. 1, pp. 365-378.\u003c/li\u003e\n\u003cli\u003eL. Javazmi, A. Young, G.J. Ash, T. Low, Kinetics of slow release of nitrogen fertiliser from multi-layered nanofibrous structures, Scientific Reports 11 (2021) 1-8.\u003c/li\u003e\n\u003cli\u003eY. Jin, F. Cai, C. Song, G. Liu, C. Chen, 2022, Degradation of biodegradable plastics by anaerobic digestion: Morphological, micro-structural changes and microbial community dynamics, Science of The Total Environment vol. 834, 155167.\u003c/li\u003e\n\u003cli\u003eM.R. Ketabchi, M. Khalid, C.T. Ratnam, S. Manickam, R. Walvekar, M.E. Hoque, 2016, Sonosynthesis of cellulose nanoparticles (CNP) from kenaf fiber: Effects of processing parameters, Fibers and Polymers vol. 17, pp. 1352-1358.\u003c/li\u003e\n\u003cli\u003eJ. Kov\u0026aacute;cs, T. Tabi, 2011, Examination of starch preprocess drying and water absorption of injection‐molded starch‐filled poly (lactic acid) products, Polymer Engineering \u0026amp; Science vol. 51 no. 5, pp. 843-850.\u003c/li\u003e\n\u003cli\u003eA.J. Lasprilla, G.A. Martinez, B.H. Lunelli, A.L. Jardini, R. Maciel Filho, 2012, Poly-lactic acid synthesis for application in biomedical devices \u0026mdash; A review, Biotechnology Advances vol, 30, pp. 321-328.\u003c/li\u003e\n\u003cli\u003eB. Liu, T. Guan, G. Wu, Y. Fu, Y. Weng, 2022, Biodegradation behavior of degradable mulch with poly (butylene adipate-co-terephthalate)(PBAT) and poly (butylene succinate) (PBS) in simulation marine environment, Polymers vol.14 no. 8, 1515.\u003c/li\u003e\n\u003cli\u003eJ. Lunt, 1998, Large-scale production, properties and commercial applications of polylactic acid polymers, Polymer Degradation and Stability vol. 59 no. 1-3, pp. 145-152.\u003c/li\u003e\n\u003cli\u003eP. Malathi, K. Sellamuthu, K. Sivakumar, 2021, Nutrient encapsulation for enhancing yield and sustaining soil health, Biotica Research Today vol. 3, 1155-1157.\u003c/li\u003e\n\u003cli\u003eS. Nanda, B.R. Patra, R. Patel, J. Bakos, A.K. Dalai, 2021, Innovations in applications and prospects of bioplastics and biopolymers: A review, Environmental Chemistry Letters vol. 20, pp. 379-395.\u003c/li\u003e\n\u003cli\u003eS. Notaro, E. Lovera, A. Paletto, Consumers\u0026rsquo; preferences for bioplastic products: A discrete choice experiment with a focus on purchase drivers, 2022, Journal of Cleaner Production vol. 330, 129870.\u003c/li\u003e\n\u003cli\u003eJ.R.A. Pires, V.G.L. Souza, P. Fuci\u0026ntilde;os, L. Pastrana, A.L. Fernando, Methodologies to assess the biodegradability of bio-based Polymers \u0026mdash; Current knowledge and existing gaps, Polymers 14 (2022) 1359.\u003c/li\u003e\n\u003cli\u003eD.C. Rego, H.L. Corr\u0026ecirc;a, 2022, Biopolymers applied to packaging: A brief literature review on their impact on sustainability, vol. 4 no. 2, pp. 4-14.\u003c/li\u003e\n\u003cli\u003eN.N. Rohidi, S.A. Othman, Properties of irradiated bioplastic - A review, Proceedings of the 3rd International Conference on Green Environmental Engineering and Technology, Springer, 2022, pp. 161-169.\u003c/li\u003e\n\u003cli\u003eN.A. Rosli, M. Karamanlioglu, H. Kargarzadeh, I. Ahmad, 2021, Comprehensive exploration of natural degradation of poly (lactic acid) blends in various degradation media: A review, International journal of biological macromolecules vol. 187, pp. 732-741.\u003c/li\u003e\n\u003cli\u003eD. Seshikala, M.S. Charya, 2012, Collection and screening of Basidiomycetes for better lignin degraders, International Journal of Life Sciences Biotechnology and Pharma Research vol. 4 no. 1, pp. 203-211.\u003c/li\u003e\n\u003cli\u003eS. Sharma, A. Majumdar, B.S. Butola, 2021, Tailoring the biodegradability of polylactic acid (PLA) based films and ramie-PLA green composites by using selective additives, International Journal of Biological Macromolecules vol. 181, pp. 1092-1103.\u003c/li\u003e\n\u003cli\u003eR. Shogren, W. Doane, D. Garlotta, J. Lawton, J. Willett, 2003, Biodegradation of starch/polylactic acid/poly (hydroxyester-ether) composite bars in soil, Polymer Degradation and Stability vol. 79 no. 3, pp. 405-411.\u003c/li\u003e\n\u003cli\u003eB.X. Sun, C.Z. Chuai, S. Luo, Y. Guo, X.Q. Feng, 2022, Biodegradability of poly (butylene succinate) under enzymatic degradation, Advanced Materials Research vol. 750-752, pp. 1318-1321.\u003c/li\u003e\n\u003cli\u003eN.A.A.B. Taib, M.R. Rahman, D. Huda, K.K. Kuok, S. Hamdan, M.K.B. Bakri, M.R.M.B. Julaihi, A. Khan, 2022, A review on poly lactic acid (PLA) as a biodegradable polymer, Polymer Bulletin vol. 80, pp. 1179-1213.\u003c/li\u003e\n\u003cli\u003eS. Teixeira, K.M. Eblagon, F. Miranda, M.F. R. Pereira, J.L. Figueiredo, 2021, Towards controlled degradation of poly (lactic) acid in technical applications, C: Journal of Carbon Research vol. 7 no. 2, 42.\u003c/li\u003e\n\u003cli\u003eN. Tripathi, M. Misra, A.K. Mohanty, 2021, Durable polylactic acid (PLA)-based sustainable engineered blends and biocomposites: Recent developments, challenges, and opportunities, ACS Engineering Au vol. 1 no. 1, pp. 7-38.\u003c/li\u003e\n\u003cli\u003eH. Urayama, T. Kanamori, Y. Kimura, 2002, Properties and biodegradability of polymer blends of poly(L-lactide)s with different optical purity of the lactate units, Macromolecular Materials and Engineering vol. 287 no. 2, pp. 116-121.\u003c/li\u003e\n\u003cli\u003eR.A. Wilkes, L. Aristilde, 2017, Degradation and metabolism of synthetic plastics and associated products by Pseudomonas sp.: capabilities and challenges, Journal of applied microbiology vol. 123 no. 3, pp. 582-593.\u003c/li\u003e\n\u003cli\u003eC.S. Wu, 2005, Improving polylactide/starch biocomposites by grafting polylactide with acrylic acid\u0026ndash;characterization and biodegradability assessment, Macromolecular Bioscience vol. 5 no. 4, pp. 352-361.\u003c/li\u003e\n\u003cli\u003eS.S. Zamir, B. Fathi, A. Ajji, M. Robert, S. Elkoun, 2022, Biodegradation of modified starch/poly lactic acid nanocomposite in soil, Polymer Degradation and Stability vol. 199, 109902.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"environmental-science-and-pollution-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"espr","sideBox":"Learn more about [Environmental Science and Pollution Research](https://www.springer.com/journal/11356)","snPcode":"11356","submissionUrl":"https://submission.nature.com/new-submission/11356/3","title":"Environmental Science and Pollution Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"biocomposites, biodegradation, water absorption, thermal stability, kinetics","lastPublishedDoi":"10.21203/rs.3.rs-2928168/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2928168/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe bio- and thermal degradation as well as the water absorption properties of a novel biocomposite comprising cellulose nanoparticles, natural rubber and polylactic acid have been investigated. The biodegradation process was studied through an assembled condition based on the soil collected from the central Malaysian palm oil forests located in the University of Nottingham Malaysia. The effects of the presence of the cellulose nanoparticles and natural rubber on the biodegradation of polylactic acid were investigated. The biodegradation process was studied \u003cem\u003evia\u003c/em\u003e thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). It was understood that the reinforcement of polylactic acid with cellulose nanoparticles and natural rubber increases the thermal stability by ~20 °C. Limited amorphous regions on the surface of the cellulose nanoparticles accelerated the biodegradation and water absorption processes. Based on the obtained results, it is predicted that complete biodegradation of the synthesised biocomposites can take place in 3062 h, highlighting promising agricultural applications for this biocomposite.\u003c/p\u003e","manuscriptTitle":"Synthesis of a New Biocomposite for Fertiliser Coating: Assessment of Biodegradabilityand Thermal Stability","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-06-14 14:08:32","doi":"10.21203/rs.3.rs-2928168/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revision","date":"2023-06-25T09:13:48+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2023-06-12T08:53:36+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-06-11T07:49:19+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Environmental Science and Pollution Research","date":"2023-06-09T10:31:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2023-05-30T04:43:47+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Science and Pollution Research","date":"2023-05-24T04:25:55+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-science-and-pollution-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"espr","sideBox":"Learn more about [Environmental Science and Pollution Research](https://www.springer.com/journal/11356)","snPcode":"11356","submissionUrl":"https://submission.nature.com/new-submission/11356/3","title":"Environmental Science and Pollution Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"9a95e598-a13a-4651-983f-b6b591252fe7","owner":[],"postedDate":"June 14th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-10-16T21:55:45+00:00","versionOfRecord":{"articleIdentity":"rs-2928168","link":"https://doi.org/10.1007/s11356-023-28892-0","journal":{"identity":"environmental-science-and-pollution-research","isVorOnly":false,"title":"Environmental Science and Pollution Research"},"publishedOn":"2023-07-29 21:45:39","publishedOnDateReadable":"July 29th, 2023"},"versionCreatedAt":"2023-06-14 14:08:32","video":"","vorDoi":"10.1007/s11356-023-28892-0","vorDoiUrl":"https://doi.org/10.1007/s11356-023-28892-0","workflowStages":[]},"version":"v1","identity":"rs-2928168","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2928168","identity":"rs-2928168","version":["v1"]},"buildId":"omnImTCwR2MFx8CMYfrG7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}