Synergistic effect of Sisal Fiber reinforcement and Boric acid cross-linking on the properties of PVA

Synergistic effect of Sisal Fiber reinforcement and Boric acid cross-linking on the properties of PVA | 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 Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Synergistic effect of Sisal Fiber reinforcement and Boric acid cross-linking on the properties of PVA Wasihun Techane, Mezigebu Belay, Mengsitu WoldeTinsay, Menelik Walle Mekonen This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4363486/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 23 May, 2025 Read the published version in Discover Materials → Version 1 posted 12 You are reading this latest preprint version Abstract Plastics play a crucial role in modern human life. While plastics have versatile applications, they are mainly serving for packing purpose. Many of plastics made mare used for packaging application of petrochemicals derivatives. Even though, they fulfill most of the criteria’s as good packing materials, they are not biodegradable. This causes serious environmental pollution. As a result, biodegradable plastics have emerged as an alternative to conventional plastics. Polyvinyl alcohol (PVA) is one of the biodegradable polymers that have potential applications for various purposes because of its availability, non-toxicity, and biodegradability. However, low tensile strength and high water absorption hinder its application. To overcome this drawback, locally extracted natural biodegradable sisal fiber was used as reinforcement. The sisal fiber was extracted from sisal plant found in Ethiopian highland. After the extraction of the fiber, 20% NaOH was used for treatment in order to enhance interfacial strength between the sisal fiber and the matrix. The Composites were made by mixing 0/100, 10/90, and 20/80 weight percent using the solution casting technique. In addition to this, a cross-linker (boric acid) was used ascrosslink with PVA chains. The water intake and degradation of the samples were studied. The result shows water intake of PVA was reduced from 170% for pure PVA to 32% for the synergy of 20% reinforcement and 5.68% w/w of cross-linker concentration. The degradation obtained in 63 days was 73% for 20% reinforcement and 5.68% w/w of cross-linker concentration. The synergetic effect between boric acid cross-linking, natural sisal fiber and PVA may responsible for reduction of water absorption and improved degradation rate. Sisal Fiber PVA Cross-linker Synergetic Effect Response Surface Methodology Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 1. Introduction Petrochemical derivative materials are frequently used for packing purpose but they face challenge because of their non-biodegradable nature [ 1 ]. That cause serious environmental issue [ 2 ]. Nowadays damping plastics as a landfill or into water bodies are common practice by societies which leads to problem related to environment and health of aquatic and shortage food for grazing animals [ 3 ]. Developing, biodegradable plastics from sources such as poly lactic acid (PLA), cellulose, polystyrene, and starch that can have potential use for packaging applications [ 4 , 5 ]. The current biodegradable plastics mostly depend on forest reserves; which may affect food stock production [ 6 ] [ 6 ]. Unlike other biopolymers polyvinyl alcohol (PVA) is water soluble polymer and synthesized through continues esterification process that doesn’t cause deforestation [ 7 , 8 ]. Ester substitution with methanol in the presence of anhydrous sodium methylate or aqueous sodium hydroxide facilitates the hydrolysis of acetate group [ 9 ]. The strong blende between polyvinyl alcohols (PVA) with natural materials makes the property friendly in the range of applications [ 10 ]. The uses of water soluble plastics are very attractive commercially. However, high water absorption limits its further applications. So the incorporation of natural fibers and fillers improves the mechanical properties without compromising its degradability [ 11 , 12 ]. To overcome, high water absorption problem many research work has been reported on reinforcements and cross-linkers to improve properties of PVA. For instant, Mezigebu et al reported the synergies of GO reinforcement and di-acid crosslinking on the behavior of PVA [ 1 ]. In this report reinforcement of PVA with GO shows enhanced the tensile strength and swelling ratio with PVA. This improvement was related the synergetic effect between the reinforcement and cross-linking. The cross-linked samples showed higher strength at 0% RH than at 50% RH. The XRD, FTIR, and Raman analyses demonstrate strong interaction of PVA with GO and cross-linkers [ 1 ]. Sisal (Agave sisalana) is one of the plant fibers that are used to improve the properties of biodegradable polymers because it has good-quality of physical characteristics such as a shiny yellowish-white color, strong, saltwater-resistant, and eco-friendly raw material [ 13 ]. In addition to this it’s biodegradable nature and good role in improving land productivity make it more attractive [ 14 ]. It contains 63.78% alpha-cellulose, 94.35% holocellulose, 20.91% pentosan, and 4.76% lignin [ 15 ].Usually; it is used for various applications such as carpet, mats, rope, bags, and other handicrafts [ 14 ].The quality of textiles made from sisal fiber could be improved by chemical treatments[ 16 ]. Cross-linkers reduce the swelling ratio by restricting the mobility of the polymer chain and reducing number of hydroxyl groups on poly vinyl alcohol (PVA). The cross-linking parameters such as concentration of cross-linker, cross-linking temperature and cross-linking time affect the extent of cross-linking and hence, the properties of the modified polymer [ 17 ]. While reinforcements and cross-linkers have been commonly used for improvement properties of PVA the synergistic effect with sisal fiber reinforcement and boric acid cross-linkers is not yet reported in the literature. In this work, we reported PVA cross-linked with boric acid and reinforced with sisal fiber and the result demonstrated that reduce water absorption that resulted from the synergistic effect between boric acid cross-linker and sisal fiber reinforcement. was studied by optimizing the concentration of each enforcement on water absorption of PVA. The result demonstrate 2. Experimental 2.1 Chemicals and reagents All reagents used in this work were analytical grade and utilized without farther purification. Polyvinyl (PVA) (98%) hydrolysis, (7200 gm/mole) molecular weight, Viscosity of 4% aqueous solution at 20 o C, and (1% max) ash content were obtained from Nice Chemical Ltd. (India). Boric acid (99.5%, Mw = 61.83 g/mol), glycerol (98%), and mold release spray were used. Natural sisal fiber was extracted from the natural sisal plant obtained from south-west Debrezeit, Ethiopia. 2.2 Methods Solution-casting method was used to produce natural sisal fiber reinforced/PVA, composite, boric acid cross-linked PVA films and pure PVA films [ 18 ]. 2.3 Extraction and preparation of the fiber The fiber extraction and preparation was done following the report by Hong X. et al with minor modification. Accordingly the required amounts of sisal plant leaves were collected from Debrezeit Tasse Mountain, Ethiopia. The fibers were extracted through hand extraction with a knife. Initially, the leaves were trimmed in the longitudinal direction into thin strips for ease of fiber extraction. Then, the extracted fiber was washed with pure water in order to loosen and separate the fiber until individual fibers were obtained. Then, the extracted fibers were sun-dried, which whitened the fiber. Once dried, the sisal fibers were ready for the preparation of samples [ 19 ]. The extraction process of sisal fiber is shown in Fig. 1 below. 2.3 Chemical treatment of the Fiber After the fibers were extracted and chopped in different size, it was treated with 20% sodium hydroxide (NaOH) solution in order to enhance the bonding between the fiber and the polymer (Fig. 2d). The fibers were then washed thoroughly with water to remove the excess of NaOH sticking to the fiber as shown in (Fig. 2a, b and c. Finally, the fibers were allowed to dry in sun light for at least three days as shown (Fig. 2) below. $$F\text{i}\text{b}\text{e}\text{r}-\text{O}\text{H}+NaOH \to Fiber-{O}^{-}{Na}^{+}+ {H}_{2}O- -----------\left(2.1\right)$$ 2.4 Statistical optimization of Sisal Fiber Reinforced-PVA Response surface methodology based on central composite design using Design Expert 7.0.0 was applied to maximize the biodegradability and minimize the water absorption and permeability of the films. Basically, cross-linker concentration, cross-linking time, and cross-linking temperature were the most possible factors that affected the development of SFR/PVA. Therefore, they were selected to generate the experimental matrix by CCD with a cross-linker concentration level of 0 to 5.68 w/w, a cross-linking temperature of 95°C–120°C, and a cross-linking time of 0 to 35 minutes. The matrix was designed with 20 runs, 6 replications of the center point, and 14 axial points. 2.5 Preparation and characterization of films Pure PVA films, cross-linked PVA films with boric acid, and reinforced PVA films with treated and untreated short sisal fiber were prepared. A total of 60 varieties of samples were prepared. Then boundaries were set for the required size of the film to be cast using a thick glass Petri dish. Then the sample sheets were removed, and specimens were cut as per ASTM standards. The moisture absorption properties were evaluated as per ASTM D-570. 2.5.1 Preparation of pure PVA Films Initially the pure PVA without cross-linker was prepared. 10 gm of Pure PVA was dissolved in 100 mL distilled water. After PVA was dissolved, 5 mL of glycerol was added and heated constantly at 80°C in a glass reactor; the mixture was stirred for 10 minutes at 95°C and casted on 140 mm petri dish and finally air dried at room temperature for 48 hrs. 2.5.2 Preparation of PVA/Sisal Fiber Films 10 g of PVA was dissolved in 100 mL of distilled water at 95°C for 2 hours. The required amount of SFR of different fiber lengths (5, 10, and 15 mm) was added to the PVA solution and then mixed under stirring for 10 min. After mixing the reaction mixture for 10 minutes, 5 mL of glycerol was added as a plasticizer and was further mixed for 30 minutes. The PVA-SFR films were cast in a 140-mm petri dish and dried at room temperature until the weight was equilibrated. Composites of 0, 10, and 20% SFR with respect to PVA were prepared. Here, the thickness of the film was measured using a micrometer during the experimentation process [ 20 ]. 2.5.3 Preparation of PVA Films with Boric Acid 10 gm of PVA was dissolved in 100 mL distilled water at 85°C for 2hrs. The reaction mixture was brought to 120°C and the required amount of boric acid (0, 3, 4 and 5.68% w/w) with respect to PVA was added followed by stirring for 2hrs. at the same temperature. 2.6 Cross-Linking of SFR-PVA Films with Cross-linker 10 g of PVA was dissolved in 100 mL of deionized water at 95°C for 2 hours. The required amount of SFR (5 mm, 10 mm, and 15 mm) was added to the PVA solution and then mixed for 30 minutes. Then, 5.68% w/w of boric acid was added. After adding boric acid, the reaction mixture was brought to 120–128.5°C and mixed under stirring for 2 hours for cross-linking. The solution was cooled to 35°C and cast in a 140-mm polystyrene petri dish. The films were dried at room temperature until the weight was equilibrated. Film with an average thickness of 0.176 mm was peeled off and reserved for further testing. The sisal/PVA composite was prepared at three different ratios, varying the sisal loading from 0 wt% to 20 wt%. The same was applied for all the film-type preparations. 2.7 Characterization of the film 2.7.1 Moisture content For the water absorption test, the specimens were dried in an oven for a specified time and temperature and then placed in a desiccator to cool. Immediately upon cooling, the specimens were weighed. The material was then immersed in water at 23°C for 24 hours. Specimens were removed, patted dry with a lint free cloth, and weighed. The amount of moisture content in the specimens was measured initially by measuring the weight of each sample up to a minimum of 0.2195 gm. After drying the sample in oven for one hour at 50°C, it was allowed to cool for 10 minutes and the weight was measured. The difference between the initial weight and the weight after drying was the amount of moisture content in the specimen. The moisture content was calculated using the following formula (Dr. P.Ravinder Reddy et al., 2018). % Moisture = \(\frac{\text{w}\text{t}.\text{o}\text{f} \text{w}\text{a}\text{t}\text{e}\text{r}}{\text{w}\text{t}.\text{o}\text{f} \text{d}\text{r}\text{y} \text{m}\text{a}\text{t}\text{e}\text{r}\text{i}\text{a}\text{l}}*100------------------\left(2.2\right)\) 2.7.2 Water Absorption test Swelling study was performed by measuring the initial weight of a dried sample using a digital microbalance and immersing 10 mm × 5.3 mm pieces of film in 2500 mL of distilled water for 24 hrs. The films were then removed and dried with tissue paper and the final weight of the film was measured (Fig. 3). The swelling ratio (SR) was determined using the following equation according to M. Belay et al.,2017: SR (%) = \(\frac{{M}_{f}-{M}_{o}}{{M}_{o}}*100-------------------\left(2.3\right)\) Where, M f and M 0 represent the weight of the sample after and before immersion, respectively. 2.7.3 Bio-Degradability test This test was conducted by using a sample dimension of 30 mm x 50 mm and buried in composted soil in 10 cm soil depth as cited by N.A. Zahari, N.Othman, and H.Ismail (2011 with minor modification. Degradation study of the sample was conducted to check the weight loss of the film in a regular interval of 7 days. By applying the following equation Weight loss (%) = \(\frac{{W}_{i}-{W}_{d}}{{W}_{i}}*100-----------------\left(2.4\right)\) Where, \({w}_{d}\) is the dry weight of the film after being washed with distilled water and \({w}_{i}\) is the initial dry weight of the sample. Sample washing, diring in vacuum oven was conducted until the weight loss becomes constant (Fig. 4). 2.7.4 . Water permeability test The permeability of the film as shown in (Fig. 5 ) was done on glass bottles by filling with distilled water and placed the required film size on the top of the bottle glass in order to determine the permeability characteristics of pure PVA as well as sisal fiber reinforced films with different time intervals. 3. Results and Discussion 3.1 Optimizing cross-linking time The response surface morphology based on the design of central composite using Design expert 7.0.0 software was used to maximize the bio-degradability and minimizing the water absorption and permeability of the films. To choose the best cross-linking time, 0% w/w, 10% w/w and 20% w/w of SFR/PVA film was cross-linked for 0, 5, 10, 15, 20 ,25,30 and 35 minutes. The best time for making cross-link was chosen based on the degree of degradability and minimum swelling ratio. The best time selected was used to cross-link PVA films with varying cross-linker concentration and the properties were characterized to narrow down the final cross-linking parameters [21]. The presence of hydroxyl group in PVA attracts water restricting the mobility of polymer chains thereby forming hydrogen bond with the PVA chains. Furthermore, the incoming water molecules displace the PVA chains causing swelling. Cross-linking reduces the hydroxyl groups on PVA as a result, the hydrophilicity of the polymer is reduced (figure 6 a). In addition cross-linking restricts the movement of PVA chains, which upon the amount of water entering between the polymers chains gets limited 3.2 Water swelling study Water swelling evaluation was carried out after the samples were kept in oven at 50 °C for 2 hrs. The water absorption phenomena were rapid at the beginning and slowly decreased reaching at 35 minutes of immersion. The lowest swelling ratio at 5.68% BA /PVA cross-linked sample was attained at 35 minutes (Figure 7). Swelling ratio of pure PVA (170%), PVA with 5.68 % BA without cross-linking showed a lower swelling ratio (87.52%). The reduction of swelling ratio after crosslinking demonstrate the synergetic interaction between PVA, Sisal fiber and cross-liker. This related to the reduction of the free hydroxyl group of the polymer chains due to the formation of ester bond between the sisal fiber and the polymer (Figur3 6a) [23] [22]. To obtain optimal concentration of boric acid (BA) the swelling ratio was evaluated by fixing the time at 35 minute, PVA cross-linked with various concentrations of boric acid (BA). As displayed in (Figure 8) the result demonstrate a minimum swelling ratio of 48% was achieved for 5.688% BA/PVA cross-linked samples with significant (p < 0.05) reduction in swelling ratio was due to the formation of cross-linked networks that makes hydroxyl group reduced and restricted the movement of the polymer chains. This indicates the synergetic effect between the PVA and crosslinking [23]. 3.3 Selection of boric acid concentration Once the cross-linking time was fixed to be 35 minutes, PVA with various concentrations of boric acid (BA) was cross-linked for 35 minutes and was characterized by a swelling ratio. The optimal concentration of boric acid was chosen based on the lowest swelling ratio. The swelling ratio of PVA (Figure 8) was measured to be 170%. After cross-linking with boric acid for 35 minutes, the swelling ratio was found to decrease as the concentration of the cross-linker increased. A minimum swelling ratio of 48% was achieved for 5.688% BA/PVA cross-linked samples. This significant (p < 0.05) reduction in swelling ratio was due to the formation of cross-linked networks, which not only reduced the hydroxyl groups on PVA but also restricted the movement of the polymer chains. Since the minimum swelling ratio was observed in the 5.68% BA-CL-PVA sample, 5.68% boric acid (BA) was chosen for the synergistic study of cross-linking and reinforcement. 3.4 Sisal fiber concentration and Swelling ratio To evaluate the maximum concentration of Sisal fiber and the swelling ratio of SFR/PVA (Figure 9) at 20% SFR ratio the minimum value reached 48% after which, it becomes nearly constant. The main reason of swelling ratio reduction in a fiber –reinforced composite was due to the reduction of hydrophilic OH group of PVA because of the formation of hydrogen bond between the OH of the sisal fiber and the PVA. The presence of a large number of hydroxyl groups can improve the interfacial binding between the matrix and the filler via hydrogen bonding. To improve the interfacial binding between sisal fiber and PVA, chemical cross-linking was done using boric acid. To see the effect of cross-linking on PVA the SFR kept constant (20%) and 5.68% BA was added. The result shows lower water absorption of PVA due to the synergetic effect of Sisal fiber and boric acid with PVA [24]. 3.5 Bio-degradability test To check whether the films were biodegradable or not, biodegradability test was done on soil burial experiment. The biodegradability study (Table 1 and Figure 10) showed that all the films were biodegradable. Table 1: Degradation of different samples in the soil with time (day) Volume fraction Weight loss or percentage of degradability with time (days) Number of days 7 14 21 28 35 42 49 56 63 0/100 15 19 29 33 39 43 46 51 59 100/0 20 24 27 34 43 46 55 62 70 10/90 ST 20 28 37 40 44 50 53 60 67 10/90 SNT 10 15 29 36 47 51 56 62 68 20/80 ST 16 25 29 32 38 42 50 56 62 20/80 SNT 21 26 40 49 56 60 66 70 73 Conventional Plastic 0 0 0 0 0 0 0 0 0 3.6 Water permeability test The water permeability tested by keeping the film in water at the interval of 5 minutes for 24 hours. The result shows increase in water permeability as pore or gap on the surface increase. The water permeability significantly decrease when PVA reinforced with sisal fiber and cross linked with BA. A minimum permeability of 8.4% and 8.5% was achieved for 5 mm and 10 mm fiber length for 24 hour. This shows that more fineness of the size of the material results in less percentage of permeability (Figure 11). Synergistic effect of reinforcement and cross-linking The synergistic effect of reinforcement and cross-linking (Figure 12) resulted in a significant change in the swelling ratio of the composite. The swelling ratio of 10% SFR-CL-PVA was 123%, while that of 15% and 4% boric acid-cross-linked PVA was 89%. After the integration of 20% sisal fiber reinforced (SFR) and cross-linked with 5.68% BA, the swelling ratio was decreased up to 32% (lower swelling value), which was higher than the reduction due to reinforcement or cross-linking alone. The formation of a strong cross-linked network worked together with the reinforcement to reduce the swelling ratio. The main cause of this significant reduction in swelling ratio was the enhancement of interfacial binding between PVA and SFR, the formation of cross-linked networks, and the effective interaction between SFR, PVA, and the boric acid (BA) cross-linker. 3.7 Statistical Analysis of Different Process Variable Optimization on water absorption the bio-plastic films The experimental design software 7.0.0 was employed to optimize the cross linking parameters for maximum degradability of the film and minimum water absorption. The effect of interaction parameters is shown in Figure 13 Equation in relation to coded factors 1/Swelling ratio (R) = +100.33+6.54 * A-12.02 * B-10.21* C-3.13*A*B-29.38 *A*C-9.58* B*C+4.1 *A2+9.95* B2+1.93 *C2--------------------------------------------------------------- (3.1) Equation in relation to factors 1/swelling ratio (R) =+319.38759+88.72907concentration11.34524temprature+5.93809time0.25070concentrationtem perature0.97938concentrationtime0.025543temperaturetime+4.11367+0.063651+2.13908E-003----------------(3.2) The importance and accuracy of ANOVA was tested. The result shows as displayed in table a liner interaction with coded factor A which is related to cross-linking concentration. The cross-linking concentration factors A^2, B^2 and C^2 quadratic related to percentage with significance variable less than 0.05 and mean value greater than 0.05 as shown in table 2 Table 2: Regression coefficients and significance of response surface quadratic model for water absorption Factor Coefficient Estimate df Standard Error 95% CI Low 95% CI High VIF Intercept 100.33 1 0.067 100.18 100.48 A-Concentration 6.54 1 0.045 6.44 6.64 1.00 B-Temperature -12.02 1 0.045 -12.12 -11.92 1.00 C-Time -10.21 1 0.045 -10.31 -10.11 1.00 AB -3.13 1 0.058 -3.26 -3.00 1.00 AC -29.38 1 0.058 -29.51 -29.25 1.00 BC -9.58 1 0.058 -9.71 -9.45 1.00 A^2 4.11 1 0.044 4.02 4.21 1.02 B^2 9.95 1 0.044 9.85 10.04 1.02 C^2 1.93 1 0.044 1.83 2.02 1.02 4. Conclusion In this report we study the PVA reinforced sisal fiber and cross-likened with boric acid.The cross-linking conditions such as cross-linking time, temperature and concentration of boric acid was were selected based on lowest swelling ratio. The cross-linking of PVA with 5.68% BA decreased the swelling ratio from 170–40% and increased the degradability of the bio-plastic film. The commutative effect of the SFR and cross-linking additional improve the degradability of the film and decrease the swelling ratio of the film from 170 to 32%. The practical use of this study is that to result biodegradable plastics for packaging application from the natural fiber, which is sisal fiber and PVA matrix by using boric acid as a cross linker. This study has significant importance because the materials, which produced neither, affect the food staff nor cause global warming in general. As a result, this study has great implication in the area of producing biodegradable plastics to reduce or even to eliminate the usage of synthetic plastics. Declarations Conflict of Interest The author declare that there is no conflict of interest Author Contribution MB formulated the concept, WT did the the experiment, YT and MB wrote the manuscript, MW and MWM edited the manuscript. Acknowledgment We would like to thank all staff of the Metallurgical and Materials Engineering Department, DEC, who helped us in the experiments. Data Availability Data will be provided upon reasonable request. References M. Belay, A. Sonker, R. Nagarale, and V. Verma, "Synergistic strengthening of composite films by cross-linking graphene oxide reinforcement and polyvinyl alcohol by dicarboxylic acids," Polymer International, vol. 66, 05/15 2017. M. Belay, R. Nagarale, and V. Verma, "Preparation and characterization of graphene-agar and graphene oxide-agar composites," Journal of Applied Polymer Science, vol. 134, 05/01 2017. Y. Tokiwa, B. Calabia, U. Ugwu, and S. 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Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 23 May, 2025 Read the published version in Discover Materials → Version 1 posted Editorial decision: Revision requested 19 Jul, 2024 Reviewers agreed at journal 17 Jul, 2024 Reviews received at journal 17 Jul, 2024 Reviewers agreed at journal 16 Jul, 2024 Reviewers agreed at journal 16 Jul, 2024 Reviewers agreed at journal 16 Jul, 2024 Reviews received at journal 16 Jun, 2024 Reviewers agreed at journal 13 Jun, 2024 Reviewers invited by journal 11 Jun, 2024 Editor assigned by journal 08 May, 2024 Submission checks completed at journal 08 May, 2024 First submitted to journal 03 May, 2024 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. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board 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-4363486","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":302060898,"identity":"9e412a80-48cc-4f00-8283-926227cf732a","order_by":0,"name":"Wasihun Techane","email":"","orcid":"","institution":"Ethiopian Defence Univeristy","correspondingAuthor":false,"prefix":"","firstName":"Wasihun","middleName":"","lastName":"Techane","suffix":""},{"id":302060899,"identity":"0ed892ff-0d7c-4bc4-b6bf-48b4a127bbf8","order_by":1,"name":"Mezigebu Belay","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7UlEQVRIiWNgGAWjYJCCAyDEz3D44AMgh4ePaC2SjceSDUBa2Ii2yODwGTMJEJOgFt329ocHv1TcSZzZdiyt8muOnQwbA/PDRzfwaDE7cyDhsMyZZ4n9PIeP3Zbdlgx0GJuxcQ4+LTcSDhyWbDucOHPGsbTbktuYgVp42KTxarn/sOGw5L/DiRvuvzErltxWT4SWG8wMBz82ALUcOGPG+HHbYSK0nEljOMxw7JnxzIZjydKM247zsDET8svx448//qi5I9sPjMqPP7dV2/OzNz98jE8LCDDzoDCYCSgHAcYf6IxRMApGwSgYBcgAAHP8WEvr6kziAAAAAElFTkSuQmCC","orcid":"","institution":"Ethiopian Defence Univeristy","correspondingAuthor":true,"prefix":"","firstName":"Mezigebu","middleName":"","lastName":"Belay","suffix":""},{"id":302060900,"identity":"f89be6e2-793b-4d4b-ac86-39bb6c1c4d86","order_by":2,"name":"Mengsitu WoldeTinsay","email":"","orcid":"","institution":"Ethiopian Defence Univeristy","correspondingAuthor":false,"prefix":"","firstName":"Mengsitu","middleName":"","lastName":"WoldeTinsay","suffix":""},{"id":302060901,"identity":"436b6095-8375-480c-a0c3-bc6ea6780517","order_by":3,"name":"Menelik Walle Mekonen","email":"","orcid":"","institution":"Ethiopian Defence Univeristy","correspondingAuthor":false,"prefix":"","firstName":"Menelik","middleName":"Walle","lastName":"Mekonen","suffix":""}],"badges":[],"createdAt":"2024-05-03 10:22:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4363486/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4363486/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s43939-025-00253-3","type":"published","date":"2025-05-23T15:57:25+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":56552806,"identity":"a1d28954-ce5e-4f95-8863-a3b7bb219d7d","added_by":"auto","created_at":"2024-05-15 16:31:08","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":53825,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of fiber extraction process\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/9d6353ccc03c5ab6c7e5bc9c.jpg"},{"id":56552807,"identity":"a8d8484d-410f-4e1f-a4e2-18ed4040120d","added_by":"auto","created_at":"2024-05-15 16:31:08","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":88050,"visible":true,"origin":"","legend":"\u003cp\u003ea) Sisal Fiber soaked by NaOH b) Sisal Fiber after soaked with NaOH c) Dried treated Sisal Fiber d) Reaction of NaOH with-OH group of natural fiber (According to M. A. Khan et al., 2011)\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/30e81bdbac90d11e1e184e8c.jpg"},{"id":56553376,"identity":"664d79f9-130d-4b6c-a442-18c1f40fba7f","added_by":"auto","created_at":"2024-05-15 16:47:08","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":42474,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eWater Absorption/Swelling test of the films\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/d35dbb071d0accbf134b05f0.jpg"},{"id":56553377,"identity":"1393232b-54de-4f63-abee-bc4da7b362f5","added_by":"auto","created_at":"2024-05-15 16:47:08","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":53741,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eBio-degradability test of the bio-plastic film\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/39537a0c66b2e2bc815d0635.jpg"},{"id":56552810,"identity":"6535b532-1e21-4387-b34f-b73dc1559019","added_by":"auto","created_at":"2024-05-15 16:31:08","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":21221,"visible":true,"origin":"","legend":"\u003cp\u003eWater permeability of the film\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/788aa1f5f29611c40761efaa.jpg"},{"id":56552812,"identity":"a909e502-024c-4ccc-8964-2f2237eba0a3","added_by":"auto","created_at":"2024-05-15 16:31:08","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":52851,"visible":true,"origin":"","legend":"\u003cp\u003ea) Cross-linking scheme of PVA with boric acid, b) Interfacial bond formation between PVA and Cellulose through Boric Acid crosslinking, c) Hydrogen formation between PVA and Cellulose.\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/e9a756489987197c4c599ded.jpg"},{"id":56552813,"identity":"4f0391b7-aab8-40fb-912b-3d38bc0a3f90","added_by":"auto","created_at":"2024-05-15 16:31:08","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":63802,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of cross linking time on swelling ratio of 5.68% BA/PVA cross-linked sample\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/24a8ad6788c014774a6387b6.jpg"},{"id":56552809,"identity":"64df1b57-123c-4b9b-af3e-8b0e563aafbd","added_by":"auto","created_at":"2024-05-15 16:31:08","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":26999,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of cross-linker concentration on swelling ratio of PVA\u003c/p\u003e","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/53ccaf7408d6b9d68c3972bc.jpg"},{"id":56552817,"identity":"7ece9958-f2f0-4564-903d-19ed6ba529f4","added_by":"auto","created_at":"2024-05-15 16:31:09","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":79987,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of Sisal fiber concentration on swelling ratio of PVA\u003c/p\u003e","description":"","filename":"9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/762b7a6c993f15ecf87e47df.jpg"},{"id":56553378,"identity":"88aae800-0388-4cf7-bdcd-2a657b8be095","added_by":"auto","created_at":"2024-05-15 16:47:09","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":29221,"visible":true,"origin":"","legend":"\u003cp\u003eDegradation of different samples in the soil in 63 days\u003c/p\u003e","description":"","filename":"10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/cda2ef954d504c504c3afe05.jpg"},{"id":56552815,"identity":"3f5ac15a-62a6-4f7e-88f2-2836884f9ebd","added_by":"auto","created_at":"2024-05-15 16:31:09","extension":"jpg","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":23972,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of cross-linker concentration on permeability of films\u003c/p\u003e","description":"","filename":"11.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/efe6195bd9882675bdcc782f.jpg"},{"id":56552811,"identity":"ebeffa89-1566-4faf-a27d-7e15629b7f49","added_by":"auto","created_at":"2024-05-15 16:31:08","extension":"jpg","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":25326,"visible":true,"origin":"","legend":"\u003cp\u003eSynergistic effect of sisal fiber and boric acid cross-linking on swelling of PVA\u003c/p\u003e","description":"","filename":"12.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/291cd30bc1580a648cb58742.jpg"},{"id":56552816,"identity":"3506bd89-9f70-441e-ab53-31dc29a956ac","added_by":"auto","created_at":"2024-05-15 16:31:09","extension":"jpg","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":94338,"visible":true,"origin":"","legend":"\u003cp\u003eContour (To The Left) and Response Surface (3D) (To Right) Plot Of Water Absorption Of Films in Terms Of Coded Factors (A, B \u0026amp; C)\u003c/p\u003e","description":"","filename":"13.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/88861136c2984bc76f72e826.jpg"},{"id":83459997,"identity":"814af999-37f3-44bd-8106-8b3d6d1940e7","added_by":"auto","created_at":"2025-05-26 16:08:28","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1834312,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4363486/v1/b1df297f-8ee6-42e1-a80b-4787ed84dc2c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Synergistic effect of Sisal Fiber reinforcement and Boric acid cross-linking on the properties of PVA","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003ePetrochemical derivative materials are frequently used for packing purpose but they face challenge because of their non-biodegradable nature [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. That cause serious environmental issue [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Nowadays damping plastics as a landfill or into water bodies are common practice by societies which leads to problem related to environment and health of aquatic and shortage food for grazing animals [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Developing, biodegradable plastics from sources such as poly lactic acid (PLA), cellulose, polystyrene, and starch that can have potential use for packaging applications [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe current biodegradable plastics mostly depend on forest reserves; which may affect food stock production [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Unlike other biopolymers polyvinyl alcohol (PVA) is water soluble polymer and synthesized through continues esterification process that doesn\u0026rsquo;t cause deforestation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eEster substitution with methanol in the presence of anhydrous sodium methylate or aqueous sodium hydroxide facilitates the hydrolysis of acetate group [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. The strong blende between polyvinyl alcohols (PVA) with natural materials makes the property friendly in the range of applications [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. The uses of water soluble plastics are very attractive commercially. However, high water absorption limits its further applications. So the incorporation of natural fibers and fillers improves the mechanical properties without compromising its degradability [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo overcome, high water absorption problem many research work has been reported on reinforcements and cross-linkers to improve properties of PVA. For instant, Mezigebu et al reported the synergies of GO reinforcement and di-acid crosslinking on the behavior of PVA [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In this report reinforcement of PVA with GO shows enhanced the tensile strength and swelling ratio with PVA. This improvement was related the synergetic effect between the reinforcement and cross-linking. The cross-linked samples showed higher strength at 0% RH than at 50% RH. The XRD, FTIR, and Raman analyses demonstrate strong interaction of PVA with GO and cross-linkers [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSisal (Agave sisalana) is one of the plant fibers that are used to improve the properties of biodegradable polymers because it has good-quality of physical characteristics such as a shiny yellowish-white color, strong, saltwater-resistant, and eco-friendly raw material [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In addition to this it\u0026rsquo;s biodegradable nature and good role in improving land productivity make it more attractive [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. It contains 63.78% alpha-cellulose, 94.35% holocellulose, 20.91% pentosan, and 4.76% lignin [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].Usually; it is used for various applications such as carpet, mats, rope, bags, and other handicrafts [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].The quality of textiles made from sisal fiber could be improved by chemical treatments[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCross-linkers reduce the swelling ratio by restricting the mobility of the polymer chain and reducing number of hydroxyl groups on poly vinyl alcohol (PVA). The cross-linking parameters such as concentration of cross-linker, cross-linking temperature and cross-linking time affect the extent of cross-linking and hence, the properties of the modified polymer [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWhile reinforcements and cross-linkers have been commonly used for improvement properties of PVA the synergistic effect with sisal fiber reinforcement and boric acid cross-linkers is not yet reported in the literature.\u003c/p\u003e \u003cp\u003eIn this work, we reported PVA cross-linked with boric acid and reinforced with sisal fiber and the result demonstrated that reduce water absorption that resulted from the synergistic effect between boric acid cross-linker and sisal fiber reinforcement. was studied by optimizing the concentration of each enforcement on water absorption of PVA. The result demonstrate\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e2.1 Chemicals and reagents\u003c/h2\u003e\n \u003cp\u003eAll reagents used in this work were analytical grade and utilized without farther purification.\u003c/p\u003e\n \u003cp\u003ePolyvinyl (PVA) (98%) hydrolysis, (7200 gm/mole) molecular weight, Viscosity of 4% aqueous solution at 20 \u003csup\u003eo\u003c/sup\u003eC, and (1% max) ash content were obtained from Nice Chemical Ltd. (India). Boric acid (99.5%, Mw\u0026thinsp;=\u0026thinsp;61.83 g/mol), glycerol (98%), and mold release spray were used. Natural sisal fiber was extracted from the natural sisal plant obtained from south-west Debrezeit, Ethiopia.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003e2.2 Methods\u003c/h2\u003e\n \u003cp\u003eSolution-casting method was used to produce natural sisal fiber reinforced/PVA, composite, boric acid cross-linked PVA films and pure PVA films [\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003e2.3 Extraction and preparation of the fiber\u003c/h2\u003e\n \u003cp\u003eThe fiber extraction and preparation was done following the report by Hong X. et al with minor modification. Accordingly the required amounts of sisal plant leaves were collected from Debrezeit Tasse Mountain, Ethiopia. The fibers were extracted through hand extraction with a knife. Initially, the leaves were trimmed in the longitudinal direction into thin strips for ease of fiber extraction. Then, the extracted fiber was washed with pure water in order to loosen and separate the fiber until individual fibers were obtained. Then, the extracted fibers were sun-dried, which whitened the fiber. Once dried, the sisal fibers were ready for the preparation of samples [\u003cspan class=\"CitationRef\"\u003e19\u003c/span\u003e]. The extraction process of sisal fiber is shown in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e below.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003e2.3 Chemical treatment of the Fiber\u003c/h2\u003e\n \u003cp\u003eAfter the fibers were extracted and chopped in different size, it was treated with 20% sodium hydroxide (NaOH) solution in order to enhance the bonding between the fiber and the polymer (Fig.\u0026nbsp;2d). The fibers were then washed thoroughly with water to remove the excess of NaOH sticking to the fiber as shown in (Fig.\u0026nbsp;2a, b and c. Finally, the fibers were allowed to dry in sun light for at least three days as shown (Fig.\u0026nbsp;2) below.\u003c/p\u003e\n \u003cdiv id=\"Equa\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e$$F\\text{i}\\text{b}\\text{e}\\text{r}-\\text{O}\\text{H}+NaOH \\to Fiber-{O}^{-}{Na}^{+}+ {H}_{2}O- -----------\\left(2.1\\right)$$\u003c/div\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003ch2\u003e2.4 Statistical optimization of Sisal Fiber Reinforced-PVA\u003c/h2\u003e\n \u003cp\u003eResponse surface methodology based on central composite design using Design Expert 7.0.0 was applied to maximize the biodegradability and minimize the water absorption and permeability of the films. Basically, cross-linker concentration, cross-linking time, and cross-linking temperature were the most possible factors that affected the development of SFR/PVA. Therefore, they were selected to generate the experimental matrix by CCD with a cross-linker concentration level of 0 to 5.68 w/w, a cross-linking temperature of 95\u0026deg;C\u0026ndash;120\u0026deg;C, and a cross-linking time of 0 to 35 minutes. The matrix was designed with 20 runs, 6 replications of the center point, and 14 axial points.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003e2.5 Preparation and characterization of films\u003c/h2\u003e\n \u003cp\u003ePure PVA films, cross-linked PVA films with boric acid, and reinforced PVA films with treated and untreated short sisal fiber were prepared. A total of 60 varieties of samples were prepared. Then boundaries were set for the required size of the film to be cast using a thick glass Petri dish. Then the sample sheets were removed, and specimens were cut as per ASTM standards. The moisture absorption properties were evaluated as per ASTM D-570.\u003c/p\u003e\n \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.1 Preparation of pure PVA Films\u003c/h2\u003e\n \u003cp\u003eInitially the pure PVA without cross-linker was prepared. 10 gm of Pure PVA was dissolved in 100 mL distilled water. After PVA was dissolved, 5 mL of glycerol was added and heated constantly at 80\u0026deg;C in a glass reactor; the mixture was stirred for 10 minutes at 95\u0026deg;C and casted on 140 mm petri dish and finally air dried at room temperature for 48 hrs.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.2 Preparation of PVA/Sisal Fiber Films\u003c/h2\u003e\n \u003cp\u003e10 g of PVA was dissolved in 100 mL of distilled water at 95\u0026deg;C for 2 hours. The required amount of SFR of different fiber lengths (5, 10, and 15 mm) was added to the PVA solution and then mixed under stirring for 10 min. After mixing the reaction mixture for 10 minutes, 5 mL of glycerol was added as a plasticizer and was further mixed for 30 minutes. The PVA-SFR films were cast in a 140-mm petri dish and dried at room temperature until the weight was equilibrated. Composites of 0, 10, and 20% SFR with respect to PVA were prepared. Here, the thickness of the film was measured using a micrometer during the experimentation process [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e\n \u003ch2\u003e2.5.3 Preparation of PVA Films with Boric Acid\u003c/h2\u003e\n \u003cp\u003e10 gm of PVA was dissolved in 100 mL distilled water at 85\u0026deg;C for 2hrs. The reaction mixture was brought to 120\u0026deg;C and the required amount of boric acid (0, 3, 4 and 5.68% w/w) with respect to PVA was added followed by stirring for 2hrs. at the same temperature.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003e2.6 Cross-Linking of SFR-PVA Films with Cross-linker\u003c/h2\u003e\n \u003cp\u003e10 g of PVA was dissolved in 100 mL of deionized water at 95\u0026deg;C for 2 hours. The required amount of SFR (5 mm, 10 mm, and 15 mm) was added to the PVA solution and then mixed for 30 minutes. Then, 5.68% w/w of boric acid was added. After adding boric acid, the reaction mixture was brought to 120\u0026ndash;128.5\u0026deg;C and mixed under stirring for 2 hours for cross-linking. The solution was cooled to 35\u0026deg;C and cast in a 140-mm polystyrene petri dish. The films were dried at room temperature until the weight was equilibrated. Film with an average thickness of 0.176 mm was peeled off and reserved for further testing. The sisal/PVA composite was prepared at three different ratios, varying the sisal loading from 0 wt% to 20 wt%. The same was applied for all the film-type preparations.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003e2.7 Characterization of the film\u003c/h2\u003e\n \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e\n \u003ch2\u003e2.7.1 Moisture content\u003c/h2\u003e\n \u003cp\u003eFor the water absorption test, the specimens were dried in an oven for a specified time and temperature and then placed in a desiccator to cool. Immediately upon cooling, the specimens were weighed. The material was then immersed in water at 23\u0026deg;C for 24 hours. Specimens were removed, patted dry with a lint free cloth, and weighed.\u003c/p\u003e\n \u003cp\u003eThe amount of moisture content in the specimens was measured initially by measuring the weight of each sample up to a minimum of 0.2195 gm. After drying the sample in oven for one hour at 50\u0026deg;C, it was allowed to cool for 10 minutes and the weight was measured. The difference between the initial weight and the weight after drying was the amount of moisture content in the specimen. The moisture content was calculated using the following formula (Dr. P.Ravinder Reddy et al., 2018).\u003c/p\u003e\n \u003cp\u003e% Moisture = \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{\\text{w}\\text{t}.\\text{o}\\text{f} \\text{w}\\text{a}\\text{t}\\text{e}\\text{r}}{\\text{w}\\text{t}.\\text{o}\\text{f} \\text{d}\\text{r}\\text{y} \\text{m}\\text{a}\\text{t}\\text{e}\\text{r}\\text{i}\\text{a}\\text{l}}*100------------------\\left(2.2\\right)\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e\n \u003ch2\u003e2.7.2 Water Absorption test\u003c/h2\u003e\n \u003cp\u003eSwelling study was performed by measuring the initial weight of a dried sample using a digital microbalance and immersing 10 mm \u0026times; 5.3 mm pieces of film in 2500 mL of distilled water for 24 hrs. The films were then removed and dried with tissue paper and the final weight of the film was measured (Fig.\u0026nbsp;3). The swelling ratio (SR) was determined using the following equation according to M. Belay et al.,2017:\u003c/p\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eSR (%) = \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{{M}_{f}-{M}_{o}}{{M}_{o}}*100-------------------\\left(2.3\\right)\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/div\u003e\n \u003cp\u003eWhere, M\u003csub\u003ef\u003c/sub\u003e and M\u003csub\u003e0\u003c/sub\u003e represent the weight of the sample after and before immersion, respectively.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\n \u003ch2\u003e2.7.3 Bio-Degradability test\u003c/h2\u003e\n \u003cp\u003eThis test was conducted by using a sample dimension of 30 mm x 50 mm and buried in composted soil in 10 cm soil depth as cited by N.A. Zahari, N.Othman, and H.Ismail (2011 with minor modification. Degradation study of the sample was conducted to check the weight loss of the film in a regular interval of 7 days. By applying the following equation\u003c/p\u003e\n \u003cp\u003eWeight loss (%) = \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{{W}_{i}-{W}_{d}}{{W}_{i}}*100-----------------\\left(2.4\\right)\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp\u003eWhere, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({w}_{d}\\)\u003c/span\u003e\u003c/span\u003e is the dry weight of the film after being washed with distilled water and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({w}_{i}\\)\u003c/span\u003e\u003c/span\u003e is the initial dry weight of the sample. Sample washing, diring in vacuum oven was conducted until the weight loss becomes constant (Fig. 4).\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec17\" class=\"Section3\"\u003e\n \u003ch2\u003e2.7.4 .\u003cstrong\u003eWater permeability test\u003c/strong\u003e\u003c/h2\u003e\n \u003cp\u003eThe permeability of the film as shown in (Fig. \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e) was done on glass bottles by filling with distilled water and placed the required film size on the top of the bottle glass in order to determine the permeability characteristics of pure PVA as well as sisal fiber reinforced films with different time intervals.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"3. Results and Discussion","content":"\u003cp\u003e\u003cstrong\u003e3.1 Optimizing cross-linking time\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe response surface morphology based on the design of central composite using Design expert 7.0.0 software was used to maximize the bio-degradability and minimizing the water absorption and permeability of the films. To choose the best cross-linking time, 0% w/w, 10% w/w and 20% w/w \u0026nbsp;of SFR/PVA film was cross-linked for 0, 5, 10, 15, 20 ,25,30 and 35 \u0026nbsp;minutes. The best time for making cross-link was chosen based on the degree of degradability and minimum swelling ratio.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe best time selected was used to cross-link PVA films with varying cross-linker concentration and the properties were characterized to narrow down the final cross-linking parameters\u0026nbsp;[21].\u003c/p\u003e\n\u003cp\u003eThe presence of hydroxyl group in PVA attracts water restricting the mobility of polymer chains thereby forming hydrogen bond with the PVA chains. Furthermore, the incoming water molecules displace the PVA chains causing swelling. Cross-linking reduces the hydroxyl groups on PVA as a result, the hydrophilicity of the polymer is reduced (figure 6 a). In addition cross-linking restricts the movement of PVA chains, which upon the amount of water entering between the polymers chains gets limited\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Water swelling study\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWater swelling evaluation was carried out after the samples were kept in oven at 50 \u0026deg;C for 2 hrs.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe water absorption phenomena were rapid at the beginning and slowly decreased reaching at 35 minutes of immersion. The lowest swelling ratio at 5.68% BA /PVA cross-linked sample was attained at 35 minutes (Figure 7). Swelling ratio of pure PVA (170%), PVA with 5.68 % BA without cross-linking showed a lower swelling ratio (87.52%). The reduction of swelling ratio after crosslinking demonstrate the synergetic interaction between \u0026nbsp;PVA, Sisal fiber and cross-liker. This related to the reduction of the free hydroxyl group of the polymer chains due to the formation of ester bond between the sisal fiber and the polymer (Figur3 6a) [23] [22].\u003c/p\u003e\n\u003cp\u003eTo obtain optimal concentration of boric acid (BA) the swelling ratio was evaluated by fixing the time at 35 minute, PVA cross-linked with various concentrations of boric acid (BA). As displayed in (Figure 8) the result demonstrate a minimum swelling ratio of 48% was achieved for 5.688% BA/PVA cross-linked samples with significant (p \u0026lt; 0.05) reduction in swelling ratio was due to the formation of cross-linked networks that makes hydroxyl group reduced and restricted the movement of the polymer chains. This indicates the synergetic effect between the PVA and crosslinking [23].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Selection of boric acid concentration\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOnce the cross-linking time was fixed to be 35 minutes, PVA with various concentrations of boric acid (BA) was cross-linked for 35 minutes and was characterized by a swelling ratio. The optimal concentration of boric acid was chosen based on the lowest swelling ratio.\u003c/p\u003e\n\u003cp\u003eThe swelling ratio of PVA (Figure 8) was measured to be 170%. After cross-linking with boric acid for 35 minutes, the swelling ratio was found to decrease as the concentration of the cross-linker increased. A minimum swelling ratio of 48% was achieved for 5.688% BA/PVA cross-linked samples. This significant (p \u0026lt; 0.05) reduction in swelling ratio was due to the formation of cross-linked networks, which not only reduced the hydroxyl groups on PVA but also restricted the movement of the polymer chains. Since the minimum swelling ratio was observed in the 5.68% BA-CL-PVA sample, 5.68% boric acid (BA) was chosen for the synergistic study of cross-linking and reinforcement.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Sisal fiber concentration and Swelling ratio\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo evaluate the maximum concentration of Sisal fiber and the swelling ratio of SFR/PVA (Figure 9) at 20% SFR ratio the minimum value reached 48% after which, it becomes nearly constant. The main reason of swelling ratio reduction in a fiber \u0026ndash;reinforced composite was due to the reduction of hydrophilic OH group of PVA because of the formation of hydrogen bond between the OH of the sisal fiber and the PVA. The presence of a large number of hydroxyl groups can improve the interfacial binding between the matrix and the filler via hydrogen bonding. To improve the interfacial binding between sisal fiber and PVA, chemical cross-linking was done using boric acid. To see the effect of cross-linking on PVA the SFR kept constant (20%) and 5.68% BA was added. The result shows lower water absorption of PVA due to the synergetic effect of Sisal fiber and boric acid with PVA [24].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.5 Bio-degradability test\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo check whether the films were biodegradable or not, biodegradability test was done on soil burial experiment. The biodegradability study (Table 1 and Figure 10) showed that all the films were biodegradable.\u003c/p\u003e\n\u003cp\u003eTable 1: Degradation of different samples in the soil with time (day)\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"684\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.035087719298245%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eVolume fraction\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"85.96491228070175%\" colspan=\"10\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eWeight loss or percentage of degradability with time (days)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.6751269035533%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eNumber of days\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.937394247038917%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e7\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.137055837563452%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e14\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.137055837563452%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e21\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.137055837563452%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e28\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.137055837563452%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e35\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.137055837563452%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e42\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.137055837563452%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e49\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.137055837563452%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e56\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.42808798646362%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e63\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.017467248908297%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0/100\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.967976710334789%\" valign=\"top\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.992721979621543%\" valign=\"top\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.017467248908297%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e100/0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.967976710334789%\" valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.992721979621543%\" valign=\"top\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.017467248908297%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e10/90 ST\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.967976710334789%\" valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.992721979621543%\" valign=\"top\"\u003e\n \u003cp\u003e67\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.017467248908297%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e10/90 SNT\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.967976710334789%\" valign=\"top\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.992721979621543%\" valign=\"top\"\u003e\n \u003cp\u003e68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.017467248908297%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e20/80 ST\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.967976710334789%\" valign=\"top\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.992721979621543%\" valign=\"top\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.017467248908297%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e20/80 SNT\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.967976710334789%\" valign=\"top\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.992721979621543%\" valign=\"top\"\u003e\n \u003cp\u003e73\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.017467248908297%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eConventional Plastic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.967976710334789%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.860262008733624%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.992721979621543%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e3.6 Water permeability test\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe water permeability tested by keeping the film in water at the interval of 5 minutes for 24 hours. The result shows increase in water permeability as pore or gap on the surface increase. The water permeability significantly decrease when PVA reinforced with sisal fiber and cross linked with BA. A minimum permeability of 8.4% and 8.5% was achieved for 5 mm and 10 mm fiber length for 24 hour. \u0026nbsp;This shows that more fineness of the size of the material results in less percentage of permeability (Figure 11).\u003c/p\u003e\n\u003cp\u003eSynergistic effect of reinforcement and cross-linking\u003c/p\u003e\n\u003cp\u003eThe synergistic effect of reinforcement and cross-linking (Figure 12) resulted in a significant change in the swelling ratio of the composite. The swelling ratio of 10% SFR-CL-PVA was 123%, while that of 15% and 4% boric acid-cross-linked PVA was 89%. After the integration of 20% sisal fiber reinforced (SFR) and cross-linked with 5.68% BA, the swelling ratio was decreased up to 32% (lower swelling value), which was higher than the reduction due to reinforcement or cross-linking alone. The formation of a strong cross-linked network worked together with the reinforcement to reduce the swelling ratio. The main cause of this significant reduction in swelling ratio was the enhancement of interfacial binding between PVA and SFR, the formation of cross-linked networks, and the effective interaction between SFR, PVA, and the boric acid (BA) cross-linker.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.7 Statistical Analysis of Different Process Variable Optimization on water absorption the bio-plastic films\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe experimental design software 7.0.0 was employed to optimize the cross linking parameters for maximum degradability of the film and minimum water absorption. The effect of interaction parameters is shown in Figure 13\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEquation in relation to \u0026nbsp;coded factors\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1/Swelling ratio (R)\u003c/strong\u003e = +100.33+6.54 * A-12.02 * B-10.21* C-3.13*A*B-29.38 *A*C-9.58* B*C+4.1 *A2+9.95* B2+1.93 *C2--------------------------------------------------------------- (3.1)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEquation in relation to factors\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1/swelling ratio\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(R)\u003c/strong\u003e=+319.38759+88.72907concentration11.34524temprature+5.93809time0.25070concentrationtem\u003cbr/\u003eperature0.97938concentrationtime0.025543temperaturetime+4.11367+0.063651+2.13908E-003----------------(3.2)\u003c/p\u003e\n\u003cp\u003eThe importance and accuracy of ANOVA was tested. The result shows as displayed in table a liner interaction with coded factor A which is related to cross-linking concentration. The cross-linking concentration factors A^2, B^2 and C^2 quadratic related to percentage with significance variable less than 0.05 and mean value greater than 0.05 as shown in table 2\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 2: Regression coefficients and significance of response surface quadratic model for water absorption\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"618\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.24271844660194%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eFactor\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.592233009708737%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCoefficient\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eEstimate\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003edf\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eStandard\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eError\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eLow\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eHigh\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eVIF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.24271844660194%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eIntercept\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.592233009708737%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e100.33\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.067\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e100.18\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e100.48\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.24271844660194%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eA-Concentration\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.592233009708737%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e6.54\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.045\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e6.44\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e6.64\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.24271844660194%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eB-Temperature\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.592233009708737%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-12.02\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.045\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-12.12\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-11.92\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.24271844660194%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eC-Time\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.592233009708737%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-10.21\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.045\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-10.31\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-10.11\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.24271844660194%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.592233009708737%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-3.13\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.058\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-3.26\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.563106796116505%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-3.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.24271844660194%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.592233009708737%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e-29.38\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n 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\u003cp\u003e\u003cstrong\u003e2.02\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1.02\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eIn this report we study the PVA reinforced sisal fiber and cross-likened with boric acid.The cross-linking conditions such as cross-linking time, temperature and concentration of boric acid was were selected based on lowest swelling ratio. The cross-linking of PVA with 5.68% BA decreased the swelling ratio from 170\u0026ndash;40% and increased the degradability of the bio-plastic film. The commutative effect of the SFR and cross-linking additional improve the degradability of the film and decrease the swelling ratio of the film from 170 to 32%.\u003c/p\u003e \u003cp\u003eThe practical use of this study is that to result biodegradable plastics for packaging application from the natural fiber, which is sisal fiber and PVA matrix by using boric acid as a cross linker. This study has significant importance because the materials, which produced neither, affect the food staff nor cause global warming in general. As a result, this study has great implication in the area of producing biodegradable plastics to reduce or even to eliminate the usage of synthetic plastics.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eConflict of Interest\u003c/h2\u003e \u003cp\u003eThe author declare that there is no conflict of interest\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eMB formulated the concept, WT did the the experiment, YT and MB wrote the manuscript, MW and MWM edited the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgment\u003c/h2\u003e \u003cp\u003eWe would like to thank all staff of the Metallurgical and Materials Engineering Department, DEC, who helped us in the experiments.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData will be provided upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eM. Belay, A. Sonker, R. Nagarale, and V. 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Osswald, \u0026quot;Effect of cross‐linking on the mechanical properties, degree of crystallinity and thermal stability of polyethylene vitrimers,\u0026quot; \u003cem\u003ePolymer Engineering \u0026amp; Science, \u003c/em\u003evol. 62, 10/20 2022.\u003c/li\u003e\n\u003cli\u003eB. Liu, J. Zhang, and H. Guo, \u0026quot;Research Progress of Polyvinyl Alcohol Water-Resistant Film Materials,\u0026quot; \u003cem\u003eMembranes (Basel), \u003c/em\u003evol. 12, Mar 20 2022.\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":"discover-materials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"dime","sideBox":"Learn more about [Discover Materials](https://www.springer.com/journal/43939)","snPcode":"","submissionUrl":"","title":"Discover Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Sisal Fiber, PVA, Cross-linker, Synergetic Effect, Response Surface Methodology","lastPublishedDoi":"10.21203/rs.3.rs-4363486/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4363486/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePlastics play a crucial role in modern human life. While plastics have versatile applications, they are mainly serving for packing purpose. Many of plastics made mare used for packaging application of petrochemicals derivatives. Even though, they fulfill most of the criteria\u0026rsquo;s as good packing materials, they are not biodegradable. This causes serious environmental pollution. As a result, biodegradable plastics have emerged as an alternative to conventional plastics. Polyvinyl alcohol (PVA) is one of the biodegradable polymers that have potential applications for various purposes because of its availability, non-toxicity, and biodegradability. However, low tensile strength and high water absorption hinder its application. To overcome this drawback, locally extracted natural biodegradable sisal fiber was used as reinforcement. The sisal fiber was extracted from sisal plant found in Ethiopian highland. After the extraction of the fiber, 20% NaOH was used for treatment in order to enhance interfacial strength between the sisal fiber and the matrix. The Composites were made by mixing 0/100, 10/90, and 20/80 weight percent using the solution casting technique. In addition to this, a cross-linker (boric acid) was used ascrosslink with PVA chains. The water intake and degradation of the samples were studied. The result shows water intake of PVA was reduced from 170% for pure PVA to 32% for the synergy of 20% reinforcement and 5.68% w/w of cross-linker concentration. The degradation obtained in 63 days was 73% for 20% reinforcement and 5.68% w/w of cross-linker concentration. The synergetic effect between boric acid cross-linking, natural sisal fiber and PVA may responsible for reduction of water absorption and improved degradation rate.\u003c/p\u003e","manuscriptTitle":"Synergistic effect of Sisal Fiber reinforcement and Boric acid cross-linking on the properties of PVA","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-15 16:31:03","doi":"10.21203/rs.3.rs-4363486/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-07-19T11:53:13+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"151168824194686320211983107285409448542","date":"2024-07-17T18:34:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-17T07:34:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"103823539004915117416334282506955431122","date":"2024-07-17T02:07:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"338161612760754998412673489918946295949","date":"2024-07-16T17:52:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"40094575257678797825975714398516975367","date":"2024-07-16T13:14:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-06-17T03:22:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"233070376505670324745830563753296380361","date":"2024-06-13T05:40:07+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-06-11T17:37:16+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-05-08T20:48:44+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-05-08T20:48:31+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Materials","date":"2024-05-03T10:20:26+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"discover-materials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"dime","sideBox":"Learn more about [Discover Materials](https://www.springer.com/journal/43939)","snPcode":"","submissionUrl":"","title":"Discover Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"599104e2-e33a-42a5-9431-912b943a6c2f","owner":[],"postedDate":"May 15th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-05-26T16:00:40+00:00","versionOfRecord":{"articleIdentity":"rs-4363486","link":"https://doi.org/10.1007/s43939-025-00253-3","journal":{"identity":"discover-materials","isVorOnly":false,"title":"Discover Materials"},"publishedOn":"2025-05-23 15:57:25","publishedOnDateReadable":"May 23rd, 2025"},"versionCreatedAt":"2024-05-15 16:31:03","video":"","vorDoi":"10.1007/s43939-025-00253-3","vorDoiUrl":"https://doi.org/10.1007/s43939-025-00253-3","workflowStages":[]},"version":"v1","identity":"rs-4363486","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4363486","identity":"rs-4363486","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}