Fabrication and Characterization of Potato Starch Bioplastics for 3d Printing

Fabrication and Characterization of Potato Starch Bioplastics for 3d Printing | 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 Fabrication and Characterization of Potato Starch Bioplastics for 3d Printing Sergio Gómez Suarez, Roberto Alonso González-Lezcano, Rolando Enrique Guzmán López This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5856957/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Bioplastics are becoming increasingly important due to their positive impact on the environment. This trend has spurred the development of new production techniques, such as 3D printing, emphasizing the need for efficient and sustainable applications of these materials. This article focuses on the preparation of bioplastic filaments for 3D printers using potato starch as the main raw material through the extrusion process. The filaments were prepared with different proportions of starch, glycerin, and distilled water and subjected to thermal analysis using DSC. 3D printing was performed using an Ender 3 V2 printer, and specimens were prepared for tensile testing according to ASTM D638-14 and flexure testing according to ISO 178:2019 for mechanical characterization. It was observed that filaments with higher glycerin content exhibited brittleness and slippage problems in the printer feed motor, making printing impossible. Suitable extrusion and 3D printer bed temperatures were defined. Although the mechanical properties obtained were modest, they are considered adequate for this type of material, suggesting the feasibility of using bioplastics in 3D printing. Potato starch Bioplastics Extrusion Filament 3D printing 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 Nature offers a wide range of biodegradable polymers, including starch, which has promising potential to replace traditional petroleum-based polymers that are considered environmentally undesirable due to their negative impact on the environment [1]. Starch-based bioplastics are gaining popularity due to their biodegradability and excellent physical properties [2]. In addition, promoting the use of potato starch has a positive socio-economic impact, particularly for potato growers in the agricultural sector. This translates into increased income and a stronger local economy, providing a source of stability and prosperity for farming communities [3]. Although starch-based packaging is already on the market, it has some disadvantages compared to conventional plastics, such as poor vapor and oxygen barrier and less than optimal mechanical properties. Overcoming these limitations requires a better understanding of their processability and potential for commercialization [4]. Starch-based plastics have a wide range of applications in agricultural, medical, pharmaceutical and food packaging. These materials have demonstrated significant potential, especially as more countries adopt regulations banning traditional single-use plastics [5]. Starch is widely available, particularly in the commercial forms of corn, potato, and manioc starches. These starch sources are the most studied and industrially used in the production of plastics [6]. Several traditional processing methods, such as extrusion, injection molding, compression molding, casting, and foaming, as well as newer techniques, such as 3D printing, have been used to process starch-containing polymeric materials [7]. 3D printing technology, also known as additive manufacturing, is based on a process in which objects are built up layer by layer, adding material as it is created. The technology has proven to be extremely versatile, finding application in a wide range of fields due to its ability to meet specific design requirements and enable rapid prototyping. Sectors such as biomedical, aerospace, construction, manufacturing, engineering, and food processing have enthusiastically embraced this technology, taking advantage of its benefits and innovative potential [8]. Starches have structural properties that make them ideal for 3D printing, as their gelatinization produces a viscoelastic gel, resulting in a rapid response to shear stress and thinning. Despite their promising potential as a printing material, there are hurdles to overcome for their practical application in 3D printing [9]. Printing with starch is more challenging than printing with synthetic polymers due to the inherent complexity of its molecular structure and the changes it undergoes during the 3D printing process. This is because the final functionality of starch is influenced by different levels of structure, including molar mass and crystalline configuration, adding an additional layer of complexity to the process [10]. In more recent 3D printing applications, starch has been used as a blend component in biopolymers such as PLA. This approach aims to improve the biodegradability of such biopolymers while reducing the cost of producing the final products. For example, Danbee Lee et al. [11] carried out printing using a combination of PLA, wood and potato starch, where they found that the inclusion of starch caused a decrease in the mechanical properties and thermal stability of the composites. However, they observed a remarkable increase in the biodegradability of the material. Przybytek et al. [12] conducted a study on PLA with potato starch and found that the addition of starch increased both impact strength and elongation at break. Starch is also gaining momentum in food 3D printing due to its ability to be molded into various shapes and textures, enabling the creation of customized and attractive-looking foods. In addition, starch is a biodegradable material that is safe for human consumption, making it a favorable option for the production of edible packaging and utensils. Its versatility and sustainability position it as a key resource for innovation in the food industry, offering new opportunities to create healthy and environmentally friendly products [13], [14]. It is critical to understand the specific technical parameters, such as extrusion temperatures and speeds, for filament manufacturing and subsequent 3D printing with starch. These parameters have a significant impact on the quality and integrity of printed parts. The right extrusion temperature ensures uniform melting of the material, while optimal printing speeds help maintain accuracy and consistency of layer deposition. Understanding and adjusting these factors is critical to achieving successful results in starch 3D printing, which opens the door to a wide range of applications in diverse fields, from custom manufacturing to large-scale production of biodegradable and sustainable components. [15]. This article focuses on the fabrication of bioplastic filaments for 3D printers using potato starch as the main raw material through the extrusion process. In addition, the thermal characterization of the filaments by DSC is performed. Subsequently, the 3D printing of the material and its mechanical characterization by tensile and flexural tests are carried out to determine its mechanical properties. 2. METHODS 2.1 Materials Three main components were used to create the filament: distilled water as a solvent, potato starch as a gelling agent, and glycerin as a plasticizer. The distilled water used was 99.8% pure and was verified to be free of impurities by UV-visible spectrophotometry. The pH of the water was maintained at 7.0 ± 0.1 as determined by an Extech PH100 pH meter. The potato starch was purchased from Madre Tierra in Colombia. According to the supplier's specifications, this starch provides 340 kcal (1428 kJ) of energy per 100 grams, with a fat content of 0.2%, carbohydrate content of 85% (all starch), and protein content of 0.3%. Glycerin was incorporated to improve the flexibility and elasticity of the biomaterial. The technical specifications of the glycerin provided by the manufacturer, Dismoprin, Bucaramanga, Santander, Colombia, indicate a molecular weight of 92.09 g/mol, a minimum content of 99% glycerin, a maximum of 10 ppm chlorides, a melting point of 17ºC, a boiling point of 290ºC, and a specific gravity of 1.249 at 25ºC. Figure 1 shows the mixture of water, glycerin, and potato starch fed into the extruder for the filament manufacturing process. 2.2 Filament Manufacturing A single-screw extruder equipped with four heaters distributed along the cylinder was used to produce the filament. The first heater is located at the die outlet, followed by two additional heaters located inside the extruder body. The fourth heater is located at the feed hopper inlet. The extruder used is shown in Fig. 2 . Prior to each extrusion, the extruder was preheated for 40 minutes to ensure thermal stability of the barrel and screw. The extruded filament was cooled by forced convection using a ventilation system integrated in the extruder base. The mechanism used is shown in Fig. 3 . For the production of bioplastic filaments, three experimental setups were carried out in which the proportions of the components in each mixture were adjusted. The aim was to evaluate the effect of different plasticizer concentrations, keeping constant a total volume of 90 ml of liquid, identified in preliminary tests as optimal to ensure adequate homogenization with 100 g of starch. Extruder heater temperatures were set experimentally for each configuration, starting with a lower temperature at the heater near the hopper and gradually increasing to the highest temperature at the die. In addition, the configuration with the lowest amount of glycerin required a higher temperature compared to the others. In terms of extrusion speed, preliminary tests showed that lower glycerin configurations required lower speeds. As the amount of glycerin decreased, the mixture became more viscous, making it difficult for the material to flow evenly. The ratios, temperatures, and speeds for each configuration are presented in Table 1 . Table 1 Composition of produced filaments Conf. COMPONENT TEMPERATURE (°C) Speed (rpm) Starch [g] Glycerin [ml] Water [ml] T1 T2 T3 T4 1 100 20 70 88 − 85 80 − 79 75 − 73 70 − 68 3,7 2 100 10 80 95 − 93 88 − 85 81 − 79 72 − 70 2,8 3 100 5 85 98–100 93 − 89 87 − 84 76 − 73 1,4 Once the filaments were manufactured, preliminary tests were performed on the 3D printer feed system to evaluate their automatic movement in the extrusion system. Thanks to these tests, it was possible to analyze the ability of the filaments to move continuously and without manual intervention through the printer's feed mechanism, ensuring their compatibility with the 3D printing equipment. 2.3 Thermal Analysis Thermal analysis of the bioplastic filament was performed by differential scanning calorimetry (DSC) using a TA INSTRUMENT Discovery Series instrument. The test was performed under a nitrogen atmosphere at a flow rate of 20 ml/min. The temperature range investigated was 25 to 275°C with a heating and cooling rate of 5°C/min. A 3 mg sample was used for testing. 2.4 Filament printing. The biocomposite material was printed using a Creality Ender 3 V2 3D printer, as shown in Fig. 4 . A 1 mm extrusion die was chosen to prevent the extruder from clogging during the printing process and to ensure a constant and uniform flow of material. Printing was performed using Crealty Slicer 4.8 software. The temperatures of both the extruder and the bed were adjusted according to the results of the thermal test, which will be detailed later in the results of the study. It should also be noted that there was no need to use supports during the printing process. The parameters defined in the Crealty Slicer 4.8. software for 3D printing are shown in Table 2 . Table 2 Parameters defined in the printer Quality Layer height 0.2 mm Shell Wall thickness 0.8 mm Wall line count 2 Top/Bottom Thickness 0.8 mm Top thickness 0.8 mm Botton Thickness 0.8 mm Top/Bottom pattern lines Infill Infill density 100% Infill line distance 0.4 mm Infill Pattern lines Minimun infill area 0 mm2 Speed Print speed 30 mm/s Infill Speed 30 mm/s Outer wall speed 30 mm/s travel speed 120 mm/s Travel Retraction distance 4 mm Retraction speed 25 mm/s Cooling Fan speed 100% Regular fan speed at Heigth 0.6 mm Mimimun layer time 10 s 2.5 Tensile test Tensile testing was performed according to the guidelines of ASTM D638-14, Standard Test Method for Tensile Properties of Plastics. An MTS universal machine, model C43.104, was used to perform this evaluation. The test was performed at a speed of 5 mm/min, as recommended by the ASTM standard specifications. Five specimens were fabricated with the geometry shown in Fig. 5 (all measurements are in millimeters). The mechanical results presented represent the average and standard deviation obtained from the five tests performed. 2.6 Flexural test The flexural test was performed using an MTS brand universal machine, model C43.104, according to the guidelines of ISO 178:2019, "Plastics - Determination of flexural properties". The specimens used were rectangular and flat, with dimensions of 80 mm in length, 10 mm in width, and 4 mm in thickness. The test was performed at a speed of 2 mm/min with a total of 5 specimens. Figure 6 shows the flexure test performed. 3. RESULTS 3.1 Filament manufacturing Figure 7 shows the filaments produced by extrusion using the configurations described in Table 1 . A positive correlation was found between the plasticizer concentration in the bioplastic and its elongation capacity, which translates into greater flexibility before breaking. However, this increase in ductility results in a decrease in tensile strength, making the material more fragile and prone to breakage. A similar behavior was also observed by Robiana et al [16], who investigated the use of waste-derived glycerin as a plasticizer in bioplastics made from banana peel starch. The researchers concluded that higher glycerin content increased the flexibility of the bioplastic, but at the expense of reduced tensile strength. Considering this relationship between glycerin concentration and the mechanical properties of the bioplastic, tests were conducted on the 3D printer's feed motor to evaluate the automatic movement of the filaments. Filaments with 20 ml and 10 ml of glycerin were found to be unsuitable for 3D printing due to their lack of rigidity, which made them excessively flexible. This characteristic made handling in the feed motor difficult, as the filaments tended to deform and slip in the mechanism, preventing continuous feed through the extrusion system. As a result, configurations 1 and 2 could not be used for printing because they required manual feeding, which could potentially damage the 3D printing equipment. For this reason, only configuration 3, containing 5 ml of glycerin, was used. 3.2 Thermal characterization The thermal properties of the filament in configuration 3 by DSC analysis are shown in Fig. 8 . The thermogram shows a single endothermic peak, a behavior characteristic of starch gelatinization, which was also reported by Theagarajan et al. [17] in their study of 3D printing of a rice starch. This phenomenon occurs when starch molecules absorb water and become disorganized, resulting in the breakdown of crystalline structures and an endothermic phase transition. The gelatinization of potato starch occurred within the temperature range between the onset temperature of 36.45°C and the peak temperature of 81.95°C. The values obtained are very consistent with those reported by Theagarajan et al. [17], who documented an onset temperature of 46.97°C and a peak temperature of 98.99°C for a rice starch filament. In addition, Ahmadzadeh et al. [18] recorded a peak temperature of 70°C for a filament obtained from high amylose corn starch. 3.3 Filament 3D printing. Three values were used to evaluate the 3D printer extruder temperature: 82°C, 95°C, and 105°C. These temperatures were chosen above the peak temperature because, as reported by Wu et al [19], it is critical to maintain extrusion temperatures above the gelatinization range to achieve desirable rheological properties in starch-based materials. The bed temperature was set at 35°C, slightly below the onset temperature, to ensure adequate adhesion of the molten polymer without causing premature deformation of the material in contact with the bed. This configuration provided good stability during printing and avoided deformation problems in the early layers. The results showed that the temperature of 82°C was not sufficient to properly melt the potato starch filament, as this temperature did not reach the level necessary to induce complete melting of the material, as shown in Fig. 9 . At a temperature of 95°C, an issue was observed where the filament did not melt uniformly, leading to blockages in the extruder die. These blockages posed a significant challenge, disrupting the steady material flow and resulting in poor extrusion quality during the printing process. This behavior is illustrated in Fig. 10 Successful molding was achieved at a temperature of 105°C. Figure 11 shows one of the specimens fabricated for tensile and flexural testing. 3.3. Tensile test Figure 12 shows the stress-strain curves of the samples printed with the filament. The curves show a gradual onset of deformation followed by an increase in stress until a breaking point is reached. The maximum stress shown was 5.03 MPa ± 1.18 MPa. In addition, an average modulus of elasticity of 87.94 MPa ± 29.85 MPa was observed. The results obtained are in agreement with those reported by Avérous et al [20], where they present a maximum stress of 3.3 MPa and a modulus of 45 MPa in a filament made from 67% potato starch, 24% glycerin and 9% distilled water by weight of the material. It is important to note that the maximum stress recorded is significantly influenced by both the amount of material (% filler) and the pattern selected during the 3D printing process [21]. In addition, as mentioned by Ju et al [22], the mechanical properties of starch-based bioplastics tend to be inferior to those of conventional polymers or PLA due to the less uniform and organized molecular structure, challenges in compatibility between components, specific processing conditions and intrinsic material properties such as thermal degradation or moisture absorption. 3.4 Flexural Test Figure 13 shows the curves resulting from the flexural test performed on the material. The resulting plots show an initial phase of elastic deformation characterized by a linear increase in stress with strain, reflecting the ability of the material to recover from transient deformations. Finally, the plots show a fracture point where the material reaches its strength limit and rupture occurs. The test results showed a maximum flexural stress of 11.02 MPa ± 2.65 MPa and a modulus of 570.35 MPa ± 100.82 MPa. The values obtained in this study are consistent with previous findings by Nazrine et al. [23], who investigated different bioplastics by varying the blend of PLA with potato starch. In their experiments, they observed that the flexural values were lower at 30 MPa and gradually decreased as the proportion of starch in the blend was increased. 4. Conclusions In this study, three configurations of bioplastic filaments were fabricated using potato starch as the main component, distilled water as the solvent, and glycerin as the plasticizer through an extrusion process. It was observed that a higher amount of glycerin increased the flexibility and elasticity of the material, although it also caused difficulties in sliding the filament in the feed motor during 3D printing, which prevented its effective use in the printing process. Thermal characterization by DSC revealed a single endothermic peak characteristic of starch gelatinization, confirming the thermal transition characteristic of starch-based bioplastics. This behavior indicates that the starch granules absorb heat and lose their crystalline structure, a fundamental process for applications such as 3D printing. The optimal configuration for 3D printing was achieved with a filament composed of 100 g of starch, 5 ml of glycerin, and 85 ml of distilled water, using an extrusion temperature of 105°C. Lower temperatures, such as 95°C and 82°C, were found to cause nozzle clogging, affecting print quality and limiting process continuity. The printed samples were evaluated by tensile and flexure tests to determine their mechanical properties. Although the values obtained were relatively low, they are considered adequate for the type of material produced and demonstrate the potential of potato starch-based bioplastics for applications where flexibility and biodegradability are required. This study provides relevant information for the development of functional bioplastics in 3D printing and establishes a basis for optimizing the formulation and processing of starch-based materials. Declarations Author Contributions: Conceptualization, S.G.S., C.P.G.C. and R.E.G.L.; methodology, S.G.S., C.P.G.C. , R.A.G—L and R.E.G.L; investigation, S.G.S., C.P.G.C, R.A.G.-Land R.E.G.L.; writing—original draft preparation, S.G.S., C.P.G.C. and R.E.G.L; writing—review and editing, R.A.G.-L, R.E.G.L and S.G.S.; supervision, R.E.G.L. and R.A.G.-L.; Project administration, R.E.G.L. All authors have read and agreed to the published version of the manuscript. 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González-Lezcano","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4klEQVRIiWNgGAWjYPACCyhdQbwWCSh9hmQtjG1EqDXvX3zs4Y8aCTn59sPPHnycZydncID58Ad8WmRuPEs3kDgmYczYk2ZuOHNbsrHBAbY0CXxaJCTOmEkYsEkkNkswmEnzbjuQuOEAjxl+T4C0JPyTqG+TYP8mzTvnQP2GA/yf8TpMgr/HTOJgm0QCjwQP0JaGAwkGB3gYCDiMLU2ysU/CcAZPTpnkjGPJhjMPs5nh18J/+Jjkj2828vLtx7dJfKixk+c73vwYr8MYJBLQRZjxqgcC/gOEVIyCUTAKRsGIBwDRdEGRpzA/ggAAAABJRU5ErkJggg==","orcid":"","institution":"Universidad San Pablo-CEU, CEU Universities","correspondingAuthor":true,"prefix":"","firstName":"Roberto","middleName":"Alonso","lastName":"González-Lezcano","suffix":""},{"id":404878684,"identity":"c45f7539-b6da-4c20-827d-8e6c53d9dfed","order_by":2,"name":"Rolando Enrique Guzmán López","email":"","orcid":"","institution":"Universidad Pontificia Bolivariana","correspondingAuthor":false,"prefix":"","firstName":"Rolando","middleName":"Enrique Guzmán","lastName":"López","suffix":""}],"badges":[],"createdAt":"2025-01-18 21:38:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5856957/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5856957/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":74438401,"identity":"40dffb7c-da6f-4137-b2f7-0288dcef4783","added_by":"auto","created_at":"2025-01-22 09:42:23","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":75347,"visible":true,"origin":"","legend":"\u003cp\u003eMixture of components before extrusion\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/8c0168ed02d141b81b6a4477.png"},{"id":74438768,"identity":"81e12cfe-53c9-42e5-abbd-6d7bc7f4cd60","added_by":"auto","created_at":"2025-01-22 09:50:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":199390,"visible":true,"origin":"","legend":"\u003cp\u003eExtruder used in the manufacturing process\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/6e439ac0e3bd4e55e00b34c7.png"},{"id":74438404,"identity":"f2f114ef-8941-4de9-8b66-018da89b458e","added_by":"auto","created_at":"2025-01-22 09:42:23","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":141657,"visible":true,"origin":"","legend":"\u003cp\u003eCooling mechanism used in the extrusion process\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/b4ae5bc0df1edc44e200ade1.png"},{"id":74438770,"identity":"07bb270e-2731-4613-b2b9-a9c41f38d2e2","added_by":"auto","created_at":"2025-01-22 09:50:23","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":151705,"visible":true,"origin":"","legend":"\u003cp\u003e3D printer used in the printing process\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/75ab42c827f95e8bbad97aa1.png"},{"id":74438769,"identity":"17fea7d5-d6c2-4246-a94e-57e3dcb3dcbe","added_by":"auto","created_at":"2025-01-22 09:50:23","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":18588,"visible":true,"origin":"","legend":"\u003cp\u003eTensile specimen geometry\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/7d9fb0abd34cb0d2b06877f3.png"},{"id":74438417,"identity":"7f1846b7-0a48-486c-aad6-c01464b42293","added_by":"auto","created_at":"2025-01-22 09:42:23","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":70287,"visible":true,"origin":"","legend":"\u003cp\u003eFlexural test.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/6e366e7433fb7fc7a3fccd6a.png"},{"id":74438411,"identity":"2d500d8e-e6e4-4e37-a0bd-24569b57e1fa","added_by":"auto","created_at":"2025-01-22 09:42:23","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":134063,"visible":true,"origin":"","legend":"\u003cp\u003eExtruded filaments A) Conf. 1, B) Conf. 2, C) Conf. 3\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/23cbc481636b86493ce74cc6.png"},{"id":74438419,"identity":"acbb27ea-9ca6-44d4-93a0-61b82685e4d4","added_by":"auto","created_at":"2025-01-22 09:42:24","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":36048,"visible":true,"origin":"","legend":"\u003cp\u003eDifferential calorimeter scanning (DSC)\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/abeaa3b572e6d7680895c426.png"},{"id":74438421,"identity":"03ddd765-c94e-46f6-a96b-9b6f5f44ca85","added_by":"auto","created_at":"2025-01-22 09:42:24","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":57111,"visible":true,"origin":"","legend":"\u003cp\u003ePotato starch filament at 82°C with melting problems.\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/56d9c0abd6c5c13c9b55ba87.png"},{"id":74438414,"identity":"729b7b94-bbf8-4644-9b2a-f7e0cce7b33f","added_by":"auto","created_at":"2025-01-22 09:42:23","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":135226,"visible":true,"origin":"","legend":"\u003cp\u003ePotato starch filament at 95°C with clogging problems.\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/cf5e7ec5518863f885284964.png"},{"id":74438780,"identity":"62575b4c-4192-4379-95f6-799db59bafa0","added_by":"auto","created_at":"2025-01-22 09:50:24","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":168935,"visible":true,"origin":"","legend":"\u003cp\u003eFabricated specimens A) Tension B) Flexure\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/bd6bafc65409dfe102ad93d0.png"},{"id":74438431,"identity":"7d4705b2-c9af-446b-8b5a-d5d2f614da82","added_by":"auto","created_at":"2025-01-22 09:42:24","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":68879,"visible":true,"origin":"","legend":"\u003cp\u003eStress-strain curve\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/b8d40fb4b1f5fe407284e6c3.png"},{"id":74438781,"identity":"51ae7740-2ebb-4d77-8da3-32dcca7355c4","added_by":"auto","created_at":"2025-01-22 09:50:24","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":65279,"visible":true,"origin":"","legend":"\u003cp\u003eStress-strain flexural curve\u003c/p\u003e","description":"","filename":"13.png","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/c03d345ee22b2fa9fd36da96.png"},{"id":74440357,"identity":"a1cb371f-a7b0-40e9-83f5-d978843288d5","added_by":"auto","created_at":"2025-01-22 10:06:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2214603,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5856957/v1/edd1f2a0-bd1d-4640-bbec-74f9b845c2df.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eFabrication and Characterization of Potato Starch Bioplastics for 3d Printing\u003c/p\u003e","fulltext":[{"header":"1.\tINTRODUCTION","content":"\u003cp\u003eNature offers a wide range of biodegradable polymers, including starch, which has promising potential to replace traditional petroleum-based polymers that are considered environmentally undesirable due to their negative impact on the environment [1].\u003c/p\u003e \u003cp\u003eStarch-based bioplastics are gaining popularity due to their biodegradability and excellent physical properties [2]. In addition, promoting the use of potato starch has a positive socio-economic impact, particularly for potato growers in the agricultural sector. This translates into increased income and a stronger local economy, providing a source of stability and prosperity for farming communities [3].\u003c/p\u003e \u003cp\u003eAlthough starch-based packaging is already on the market, it has some disadvantages compared to conventional plastics, such as poor vapor and oxygen barrier and less than optimal mechanical properties. Overcoming these limitations requires a better understanding of their processability and potential for commercialization [4].\u003c/p\u003e \u003cp\u003eStarch-based plastics have a wide range of applications in agricultural, medical, pharmaceutical and food packaging. These materials have demonstrated significant potential, especially as more countries adopt regulations banning traditional single-use plastics [5].\u003c/p\u003e \u003cp\u003eStarch is widely available, particularly in the commercial forms of corn, potato, and manioc starches. These starch sources are the most studied and industrially used in the production of plastics [6].\u003c/p\u003e \u003cp\u003eSeveral traditional processing methods, such as extrusion, injection molding, compression molding, casting, and foaming, as well as newer techniques, such as 3D printing, have been used to process starch-containing polymeric materials [7].\u003c/p\u003e \u003cp\u003e3D printing technology, also known as additive manufacturing, is based on a process in which objects are built up layer by layer, adding material as it is created. The technology has proven to be extremely versatile, finding application in a wide range of fields due to its ability to meet specific design requirements and enable rapid prototyping. Sectors such as biomedical, aerospace, construction, manufacturing, engineering, and food processing have enthusiastically embraced this technology, taking advantage of its benefits and innovative potential [8].\u003c/p\u003e \u003cp\u003eStarches have structural properties that make them ideal for 3D printing, as their gelatinization produces a viscoelastic gel, resulting in a rapid response to shear stress and thinning. Despite their promising potential as a printing material, there are hurdles to overcome for their practical application in 3D printing [9].\u003c/p\u003e \u003cp\u003ePrinting with starch is more challenging than printing with synthetic polymers due to the inherent complexity of its molecular structure and the changes it undergoes during the 3D printing process. This is because the final functionality of starch is influenced by different levels of structure, including molar mass and crystalline configuration, adding an additional layer of complexity to the process [10].\u003c/p\u003e \u003cp\u003eIn more recent 3D printing applications, starch has been used as a blend component in biopolymers such as PLA. This approach aims to improve the biodegradability of such biopolymers while reducing the cost of producing the final products. For example, Danbee Lee et al. [11] carried out printing using a combination of PLA, wood and potato starch, where they found that the inclusion of starch caused a decrease in the mechanical properties and thermal stability of the composites. However, they observed a remarkable increase in the biodegradability of the material. Przybytek et al. [12] conducted a study on PLA with potato starch and found that the addition of starch increased both impact strength and elongation at break.\u003c/p\u003e \u003cp\u003eStarch is also gaining momentum in food 3D printing due to its ability to be molded into various shapes and textures, enabling the creation of customized and attractive-looking foods. In addition, starch is a biodegradable material that is safe for human consumption, making it a favorable option for the production of edible packaging and utensils. Its versatility and sustainability position it as a key resource for innovation in the food industry, offering new opportunities to create healthy and environmentally friendly products [13], [14].\u003c/p\u003e \u003cp\u003eIt is critical to understand the specific technical parameters, such as extrusion temperatures and speeds, for filament manufacturing and subsequent 3D printing with starch. These parameters have a significant impact on the quality and integrity of printed parts. The right extrusion temperature ensures uniform melting of the material, while optimal printing speeds help maintain accuracy and consistency of layer deposition. Understanding and adjusting these factors is critical to achieving successful results in starch 3D printing, which opens the door to a wide range of applications in diverse fields, from custom manufacturing to large-scale production of biodegradable and sustainable components. [15].\u003c/p\u003e \u003cp\u003eThis article focuses on the fabrication of bioplastic filaments for 3D printers using potato starch as the main raw material through the extrusion process. In addition, the thermal characterization of the filaments by DSC is performed. Subsequently, the 3D printing of the material and its mechanical characterization by tensile and flexural tests are carried out to determine its mechanical properties.\u003c/p\u003e"},{"header":"2.\tMETHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 \u003cspan type=\"SmallCaps\" class=\"SmallCaps\" name=\"Emphasis\"\u003eMaterials\u003c/span\u003e\u003c/h2\u003e \u003cp\u003eThree main components were used to create the filament: distilled water as a solvent, potato starch as a gelling agent, and glycerin as a plasticizer.\u003c/p\u003e \u003cp\u003eThe distilled water used was 99.8% pure and was verified to be free of impurities by UV-visible spectrophotometry. The pH of the water was maintained at 7.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 as determined by an Extech PH100 pH meter.\u003c/p\u003e \u003cp\u003eThe potato starch was purchased from Madre Tierra in Colombia. According to the supplier's specifications, this starch provides 340 kcal (1428 kJ) of energy per 100 grams, with a fat content of 0.2%, carbohydrate content of 85% (all starch), and protein content of 0.3%.\u003c/p\u003e \u003cp\u003eGlycerin was incorporated to improve the flexibility and elasticity of the biomaterial. The technical specifications of the glycerin provided by the manufacturer, Dismoprin, Bucaramanga, Santander, Colombia, indicate a molecular weight of 92.09 g/mol, a minimum content of 99% glycerin, a maximum of 10 ppm chlorides, a melting point of 17\u0026ordm;C, a boiling point of 290\u0026ordm;C, and a specific gravity of 1.249 at 25\u0026ordm;C.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the mixture of water, glycerin, and potato starch fed into the extruder for the filament manufacturing process.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Filament Manufacturing\u003c/h2\u003e \u003cp\u003eA single-screw extruder equipped with four heaters distributed along the cylinder was used to produce the filament. The first heater is located at the die outlet, followed by two additional heaters located inside the extruder body. The fourth heater is located at the feed hopper inlet. The extruder used is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003ePrior to each extrusion, the extruder was preheated for 40 minutes to ensure thermal stability of the barrel and screw. The extruded filament was cooled by forced convection using a ventilation system integrated in the extruder base. The mechanism used is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFor the production of bioplastic filaments, three experimental setups were carried out in which the proportions of the components in each mixture were adjusted. The aim was to evaluate the effect of different plasticizer concentrations, keeping constant a total volume of 90 ml of liquid, identified in preliminary tests as optimal to ensure adequate homogenization with 100 g of starch.\u003c/p\u003e \u003cp\u003eExtruder heater temperatures were set experimentally for each configuration, starting with a lower temperature at the heater near the hopper and gradually increasing to the highest temperature at the die. In addition, the configuration with the lowest amount of glycerin required a higher temperature compared to the others.\u003c/p\u003e \u003cp\u003eIn terms of extrusion speed, preliminary tests showed that lower glycerin configurations required lower speeds. As the amount of glycerin decreased, the mixture became more viscous, making it difficult for the material to flow evenly.\u003c/p\u003e \u003cp\u003eThe ratios, temperatures, and speeds for each configuration are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\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\u003eComposition of produced filaments\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\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=\"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=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eConf.\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eCOMPONENT\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c8\" namest=\"c5\"\u003e \u003cp\u003eTEMPERATURE (\u0026deg;C)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSpeed (rpm)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eStarch [g]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGlycerin [ml]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWater [ml]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eT1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eT2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eT3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eT4\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e88\u0026thinsp;\u0026minus;\u0026thinsp;85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e80\u0026thinsp;\u0026minus;\u0026thinsp;79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e75\u0026thinsp;\u0026minus;\u0026thinsp;73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e70\u0026thinsp;\u0026minus;\u0026thinsp;68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3,7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95\u0026thinsp;\u0026minus;\u0026thinsp;93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e88\u0026thinsp;\u0026minus;\u0026thinsp;85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e81\u0026thinsp;\u0026minus;\u0026thinsp;79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e72\u0026thinsp;\u0026minus;\u0026thinsp;70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2,8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e98\u0026ndash;100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e93\u0026thinsp;\u0026minus;\u0026thinsp;89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e87\u0026thinsp;\u0026minus;\u0026thinsp;84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e76\u0026thinsp;\u0026minus;\u0026thinsp;73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1,4\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\u003eOnce the filaments were manufactured, preliminary tests were performed on the 3D printer feed system to evaluate their automatic movement in the extrusion system. Thanks to these tests, it was possible to analyze the ability of the filaments to move continuously and without manual intervention through the printer's feed mechanism, ensuring their compatibility with the 3D printing equipment.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Thermal Analysis\u003c/h2\u003e \u003cp\u003eThermal analysis of the bioplastic filament was performed by differential scanning calorimetry (DSC) using a TA INSTRUMENT Discovery Series instrument. The test was performed under a nitrogen atmosphere at a flow rate of 20 ml/min. The temperature range investigated was 25 to 275\u0026deg;C with a heating and cooling rate of 5\u0026deg;C/min. A 3 mg sample was used for testing.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4 \u003cspan type=\"SmallCaps\" class=\"SmallCaps\" name=\"Emphasis\"\u003eFilament printing.\u003c/span\u003e\u003c/h2\u003e \u003cp\u003eThe biocomposite material was printed using a Creality Ender 3 V2 3D printer, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA 1 mm extrusion die was chosen to prevent the extruder from clogging during the printing process and to ensure a constant and uniform flow of material.\u003c/p\u003e \u003cp\u003ePrinting was performed using Crealty Slicer 4.8 software. The temperatures of both the extruder and the bed were adjusted according to the results of the thermal test, which will be detailed later in the results of the study. It should also be noted that there was no need to use supports during the printing process.\u003c/p\u003e \u003cp\u003eThe parameters defined in the Crealty Slicer 4.8. software for 3D printing are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\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\u003eParameters defined in the printer\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eQuality\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLayer height\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.2 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eShell\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWall thickness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.8 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWall line count\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTop/Bottom Thickness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.8 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTop thickness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.8 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBotton Thickness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.8 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTop/Bottom pattern\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003elines\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eInfill\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfill density\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfill line distance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.4 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfill Pattern\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003elines\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMinimun infill area\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 mm2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSpeed\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrint speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30 mm/s\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfill Speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30 mm/s\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOuter wall speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30 mm/s\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003etravel speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e120 mm/s\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTravel\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRetraction distance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRetraction speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25 mm/s\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCooling\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFan speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRegular fan speed at Heigth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.6 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMimimun layer time\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 s\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=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5 Tensile test\u003c/h2\u003e \u003cp\u003eTensile testing was performed according to the guidelines of ASTM D638-14, Standard Test Method for Tensile Properties of Plastics. An MTS universal machine, model C43.104, was used to perform this evaluation. The test was performed at a speed of 5 mm/min, as recommended by the ASTM standard specifications.\u003c/p\u003e \u003cp\u003eFive specimens were fabricated with the geometry shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e (all measurements are in millimeters). The mechanical results presented represent the average and standard deviation obtained from the five tests performed.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.6 Flexural test\u003c/h2\u003e \u003cp\u003eThe flexural test was performed using an MTS brand universal machine, model C43.104, according to the guidelines of ISO 178:2019, \"Plastics - Determination of flexural properties\". The specimens used were rectangular and flat, with dimensions of 80 mm in length, 10 mm in width, and 4 mm in thickness. The test was performed at a speed of 2 mm/min with a total of 5 specimens. Figure\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e shows the flexure test performed.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"3.\tRESULTS","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n \u003ch2\u003e\u003cspan type=\"SmallCaps\" class=\"SmallCaps\" name=\"Emphasis\"\u003e3.1 Filament manufacturing\u003c/span\u003e\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e shows the filaments produced by extrusion using the configurations described in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eA positive correlation was found between the plasticizer concentration in the bioplastic and its elongation capacity, which translates into greater flexibility before breaking. However, this increase in ductility results in a decrease in tensile strength, making the material more fragile and prone to breakage. A similar behavior was also observed by Robiana et al [16], who investigated the use of waste-derived glycerin as a plasticizer in bioplastics made from banana peel starch. The researchers concluded that higher glycerin content increased the flexibility of the bioplastic, but at the expense of reduced tensile strength.\u003c/p\u003e\n \u003cp\u003eConsidering this relationship between glycerin concentration and the mechanical properties of the bioplastic, tests were conducted on the 3D printer\u0026apos;s feed motor to evaluate the automatic movement of the filaments. Filaments with 20 ml and 10 ml of glycerin were found to be unsuitable for 3D printing due to their lack of rigidity, which made them excessively flexible. This characteristic made handling in the feed motor difficult, as the filaments tended to deform and slip in the mechanism, preventing continuous feed through the extrusion system. As a result, configurations 1 and 2 could not be used for printing because they required manual feeding, which could potentially damage the 3D printing equipment. For this reason, only configuration 3, containing 5 ml of glycerin, was used.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003e\u003cspan type=\"SmallCaps\" class=\"SmallCaps\" name=\"Emphasis\"\u003e3.2 Thermal characterization\u003c/span\u003e\u003c/h2\u003e\n \u003cp\u003eThe thermal properties of the filament in configuration 3 by DSC analysis are shown in Fig. \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eThe thermogram shows a single endothermic peak, a behavior characteristic of starch gelatinization, which was also reported by Theagarajan et al. [17] in their study of 3D printing of a rice starch. This phenomenon occurs when starch molecules absorb water and become disorganized, resulting in the breakdown of crystalline structures and an endothermic phase transition.\u003c/p\u003e\n \u003cp\u003eThe gelatinization of potato starch occurred within the temperature range between the onset temperature of 36.45\u0026deg;C and the peak temperature of 81.95\u0026deg;C.\u003c/p\u003e\n \u003cp\u003eThe values obtained are very consistent with those reported by Theagarajan et al. [17], who documented an onset temperature of 46.97\u0026deg;C and a peak temperature of 98.99\u0026deg;C for a rice starch filament. In addition, Ahmadzadeh et al. [18] recorded a peak temperature of 70\u0026deg;C for a filament obtained from high amylose corn starch.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003e\u003cspan type=\"SmallCaps\" class=\"SmallCaps\" name=\"Emphasis\"\u003e3.3 Filament 3D printing.\u003c/span\u003e\u003c/h2\u003e\n \u003cp\u003eThree values were used to evaluate the 3D printer extruder temperature: 82\u0026deg;C, 95\u0026deg;C, and 105\u0026deg;C. These temperatures were chosen above the peak temperature because, as reported by Wu et al [19], it is critical to maintain extrusion temperatures above the gelatinization range to achieve desirable rheological properties in starch-based materials.\u003c/p\u003e\n \u003cp\u003eThe bed temperature was set at 35\u0026deg;C, slightly below the onset temperature, to ensure adequate adhesion of the molten polymer without causing premature deformation of the material in contact with the bed. This configuration provided good stability during printing and avoided deformation problems in the early layers.\u003c/p\u003e\n \u003cp\u003eThe results showed that the temperature of 82\u0026deg;C was not sufficient to properly melt the potato starch filament, as this temperature did not reach the level necessary to induce complete melting of the material, as shown in Fig. \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eAt a temperature of 95\u0026deg;C, an issue was observed where the filament did not melt uniformly, leading to blockages in the extruder die. These blockages posed a significant challenge, disrupting the steady material flow and resulting in poor extrusion quality during the printing process. This behavior is illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e\u003c/p\u003e\n \u003cp\u003eSuccessful molding was achieved at a temperature of 105\u0026deg;C. Figure \u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003e shows one of the specimens fabricated for tensile and flexural testing.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003e3.3. Tensile test\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e shows the stress-strain curves of the samples printed with the filament. The curves show a gradual onset of deformation followed by an increase in stress until a breaking point is reached.\u003c/p\u003e\n \u003cp\u003eThe maximum stress shown was 5.03 MPa\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18 MPa. In addition, an average modulus of elasticity of 87.94 MPa\u0026thinsp;\u0026plusmn;\u0026thinsp;29.85 MPa was observed.\u003c/p\u003e\n \u003cp\u003eThe results obtained are in agreement with those reported by Av\u0026eacute;rous et al [20], where they present a maximum stress of 3.3 MPa and a modulus of 45 MPa in a filament made from 67% potato starch, 24% glycerin and 9% distilled water by weight of the material.\u003c/p\u003e\n \u003cp\u003eIt is important to note that the maximum stress recorded is significantly influenced by both the amount of material (% filler) and the pattern selected during the 3D printing process [21].\u003c/p\u003e\n \u003cp\u003eIn addition, as mentioned by Ju et al [22], the mechanical properties of starch-based bioplastics tend to be inferior to those of conventional polymers or PLA due to the less uniform and organized molecular structure, challenges in compatibility between components, specific processing conditions and intrinsic material properties such as thermal degradation or moisture absorption.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003e3.4 Flexural Test\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e13\u003c/span\u003e shows the curves resulting from the flexural test performed on the material.\u003c/p\u003e\n \u003cp\u003eThe resulting plots show an initial phase of elastic deformation characterized by a linear increase in stress with strain, reflecting the ability of the material to recover from transient deformations. Finally, the plots show a fracture point where the material reaches its strength limit and rupture occurs.\u003c/p\u003e\n \u003cp\u003eThe test results showed a maximum flexural stress of 11.02 MPa\u0026thinsp;\u0026plusmn;\u0026thinsp;2.65 MPa and a modulus of 570.35 MPa\u0026thinsp;\u0026plusmn;\u0026thinsp;100.82 MPa.\u003c/p\u003e\n \u003cp\u003eThe values obtained in this study are consistent with previous findings by Nazrine et al. [23], who investigated different bioplastics by varying the blend of PLA with potato starch. In their experiments, they observed that the flexural values were lower at 30 MPa and gradually decreased as the proportion of starch in the blend was increased.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eIn this study, three configurations of bioplastic filaments were fabricated using potato starch as the main component, distilled water as the solvent, and glycerin as the plasticizer through an extrusion process. It was observed that a higher amount of glycerin increased the flexibility and elasticity of the material, although it also caused difficulties in sliding the filament in the feed motor during 3D printing, which prevented its effective use in the printing process.\u003c/p\u003e \u003cp\u003eThermal characterization by DSC revealed a single endothermic peak characteristic of starch gelatinization, confirming the thermal transition characteristic of starch-based bioplastics. This behavior indicates that the starch granules absorb heat and lose their crystalline structure, a fundamental process for applications such as 3D printing.\u003c/p\u003e \u003cp\u003eThe optimal configuration for 3D printing was achieved with a filament composed of 100 g of starch, 5 ml of glycerin, and 85 ml of distilled water, using an extrusion temperature of 105\u0026deg;C. Lower temperatures, such as 95\u0026deg;C and 82\u0026deg;C, were found to cause nozzle clogging, affecting print quality and limiting process continuity.\u003c/p\u003e \u003cp\u003eThe printed samples were evaluated by tensile and flexure tests to determine their mechanical properties. Although the values obtained were relatively low, they are considered adequate for the type of material produced and demonstrate the potential of potato starch-based bioplastics for applications where flexibility and biodegradability are required. This study provides relevant information for the development of functional bioplastics in 3D printing and establishes a basis for optimizing the formulation and processing of starch-based materials.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u0026nbsp;\u003c/strong\u003eConceptualization, S.G.S., C.P.G.C. and R.E.G.L.; methodology, S.G.S., C.P.G.C. , R.A.G—L and R.E.G.L; investigation, S.G.S., C.P.G.C, R.A.G.-Land R.E.G.L.; writing—original draft preparation, S.G.S., C.P.G.C. and R.E.G.L; writing—review and editing, R.A.G.-L, R.E.G.L and S.G.S.; supervision, R.E.G.L. and R.A.G.-L.; Project administration,\u003c/p\u003e\n\u003cp\u003eR.E.G.L. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e The authors would like to express their gratitude to Engineering Department of Universidad Pontificia Bolivariana- Bucaramanga, project code: BIC-008-0822-F4M1\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of Interest:\u0026nbsp;\u003c/strong\u003eThe authors declare no conflict of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eS. Arun, K. A. A. Kumar, y M. S. Sreekala, \u0026laquo;Fully biodegradable potato starch composites: effect of macro and nano fiber reinforcement on mechanical, thermal and water-sorption characteristics\u0026raquo;, \u003cem\u003eInt. J. Plast. Technol.\u003c/em\u003e, vol. 16, n.\u003csup\u003eo\u003c/sup\u003e 1, pp. 50-66, jun. 2012, doi: 10.1007/s12588-012-9026-4.\u003c/li\u003e\n\u003cli\u003eL. Kaur y J. 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Zuhri, \u0026laquo;Mechanical, Physical and Thermal Properties of Sugar Palm Nanocellulose Reinforced Thermoplastic Starch (TPS)/Poly (Lactic Acid) (PLA) Blend Bionanocomposites\u0026raquo;, \u003cem\u003ePolymers\u003c/em\u003e, vol. 12, n.\u003csup\u003eo\u003c/sup\u003e 10, p. 2216, sep. 2020, doi: 10.3390/polym12102216.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Potato starch, Bioplastics, Extrusion, Filament, 3D printing","lastPublishedDoi":"10.21203/rs.3.rs-5856957/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5856957/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBioplastics are becoming increasingly important due to their positive impact on the environment. This trend has spurred the development of new production techniques, such as 3D printing, emphasizing the need for efficient and sustainable applications of these materials. This article focuses on the preparation of bioplastic filaments for 3D printers using potato starch as the main raw material through the extrusion process. The filaments were prepared with different proportions of starch, glycerin, and distilled water and subjected to thermal analysis using DSC. 3D printing was performed using an Ender 3 V2 printer, and specimens were prepared for tensile testing according to ASTM D638-14 and flexure testing according to ISO 178:2019 for mechanical characterization. It was observed that filaments with higher glycerin content exhibited brittleness and slippage problems in the printer feed motor, making printing impossible. Suitable extrusion and 3D printer bed temperatures were defined. Although the mechanical properties obtained were modest, they are considered adequate for this type of material, suggesting the feasibility of using bioplastics in 3D printing.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e","manuscriptTitle":"Fabrication and Characterization of Potato Starch Bioplastics for 3d Printing","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-22 09:42:18","doi":"10.21203/rs.3.rs-5856957/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e7b44099-a88c-4631-87ee-598e7dcd0129","owner":[],"postedDate":"January 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-01-22T09:42:19+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-22 09:42:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5856957","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5856957","identity":"rs-5856957","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}