Valorization of Potato Peel Waste into Starch-Based Bioplastic Films using Glycerol and Sorbitol Plasticizers

This study describes the making of sago starch bioplastics using glycerol and sorbitol plasticizers with the addition of PVA and chitosan filler. It purposes to compare the effect between the addition of glycerol and sorbitol plasticizers. Bioplastic samples of sago-PVA starch have been made from a mixture of sago starch and chitosan solution that had been dissolved with acetic acid, glycerol/sorbitol plasticizer, and PVA was printed and left in the air for 24 hours, then dried in the oven for 12 hours. Testing the mechanical properties of tensile strength refers to ASTM D882 then tearing strength testing based on method C in JIS K 7128 standard. In addition to testing mechanical properties, morphological tests were also referred to as the JSM-6390A standard and biodegradability tests were carried out qualitatively with DIN EN ISO standards 846, and this Water Uptake test was referred to the ASTM-D570-98 standard. This study found that the glycerol plasticizers have a better value than other comparable materials in biodegradation testing with a value of 82.38%, However, in tensile strength test, sorbitol has better value than other material, namely with the best tensile strength value of 16.12 MPa, 142.05% in elongation, tear strength of 12,729 kgf/mm, and water uptake value of 10.34%.

Edible films present an eco-friendly alternative for food packaging compared to traditional plastic materials. This study investigates the effects of glycerol and sorbitol plasticizers on the properties of edible films. The research involves crafting these films using porang (Amorphophallus oncophyllus) starch. Glycerol plasticizers were incorporated at a concentration of 100%, while sorbitol was utilized at varying levels (0%, 25%, 50%, 75%, 100%) to evaluate their impact on film characteristics. The films were produced using the melt intercalation method at a gelatinization temperature of 80°C and a firing temperature of 70°C. Notably, the most favorable physical test outcomes were observed with adding 100% sorbitol, including thickness, density, water absorption, and degradability improvements. Meanwhile, adding 25% sorbitol yielded the highest tensile strength and elongation values.

Environmental, economic, and waste management concerns are growing as a result of the proliferation of plastics in the environment. As a potential solution to the problem of plastic pollution, glycerol plasticized starch-based bioplastics were investigated for their biodegradability. There are numerous uses of starch, a biopolymer derived from organic waste, due to its unique characteristics, such as its flexibility, degradable nature, and low cost. In the present work, starch was extracted from Solanum tuberosum (potato) peels, and starch-based bioplastics with different concentrations, i.e., 2.4 %, 24.3 %, 36.5 %, 48.6 %, and 97.2 % of glycerol plasticizer were prepared by following the casting method. Starch and bioplastics were analyzed using Fourier Transform Infrared (FTIR) spectroscopy, and their physicochemical properties were evaluated. The FTIR spectra of bioplastics with varying glycerol concentrations showed peaks at 3278 cm-1, 1643 cm-1, and 995 cm-1 corresponding to –OH, -C=O, and –C-O, respectively, confirming the formation of bioplastics. The water absorption test revealed that the bioplastic with high glycerol concentration, i.e., 97.2%, had a more significant percentage of water absorption, i.e., 79 percentage, compared to 37 % for bioplastic with low, i.e., 2.4% glycerol concentration. Water molecules enter more easily into plasticizer-rich materials, due to which bioplastic containing high glycerol concentration decays faster, i.e., in 52 days. Furthermore, a higher percentage of glycerol allowed the bioplastics to absorb acid solution for up to 42 hours and basic solution for up to 45 hours without being dissolved.

Every day, oil-based plastics are manufactured, consumed, and discarded without a second thought. To combat plastic pollution, we decided to investigate gelatin bioplastics. We analysed the effects of the increasing concentration of polyethylene glycol (PEG) and glycerol plasticizers on the mechanical properties and chemical composition of the gelatin bioplastic matrix through a series of experiments. In the first experiment, we determined their tensile strength (TS) and the elongation at break (EAB) through tensile testing. We hypothesised that increasing concentrations of the plasticizers would decrease TS and increase EAB. In the second experiment, we studied their O–H bonds by Fourier-transform infrared spectroscopy analysis (FTIR). Our second hypothesis maintained that the number of O–H bonds would increase because plasticizers disrupt polymer-polymer and polymer-water hydrogen bonds. For the mechanical properties, we observed that when the concentration of PEG and glycerol plasticizers increased so too did EAB. The rising concentrations of glycerol led to a decreasing trend with TS, whereas PEG showed an increasing trend. The FTIR spectrum revealed that a high abundance of O–H bonds was present at the strong and broad absorption peak of 3400 cm-1, with the pure gelatin films having the highest absorption, followed by glycerol-plasticized films and PEG-plasticized films having the least absorption. We concluded that 3% w/v PEG film outperformed other PEG films and 3% w/v glycerol films. The cytotoxicity results showed that all films had a cell viability above the threshold of 75% and hence food-safe.

Synthesis and characterization of bioplastic films from potato peel starch; effect of glycerol as plasticizer

This research investigated effect of morphological, mechanical and physical properties on biodegradable plastic made from porang starch with chitosan using, sorbitol plasticizer at concentration 60 and 80 wt%, with the addition of glycerol plasticizer at various concentrations (0%, 25%, 50%, 75%, 100%), made using the melt intercalation method with a gelatinization temperature of 80°C and drying temperature of 70°C. Plasticizer was added to improve flexibility and water absorption of biodegradable plastic properties. Increasing the concentration of the plasticizer resulted in an increase in the elongation of the biodegradable plastic. The biodegradable plastic showed greater tensile strength before addition glycerol plasticizer 1,9191 MPa at 60% concentration and 1,3018 MPa at 80%. Conversely, the addition of 100% glycerol concentration showed an increase in elongation of 77.7764% at 60% sorbitol and 171.0562 at 80% sorbitol. SEM characterization results still showed agglomeration and FTIR not showed any new functional groups. The results of this research indicate that the percentage and kind of plasticizer influence the physical, mechanical, morphological and degradation properties to porang starch biodegradable plastics.

The synthetic plastics that made from petroleum material have been widely used in all industrial sectors. They cause some serious problems for the environment. There are semi-synthetic plastics or biodegradable plastics which are made from natural polymers such as cellulose to mitigate this problem. Biodegradable plastics can fulfill the needs of society because they can be decomposed easily into the environment. This research used laboratory experimental methods through several processes: kapok fiber isolation, cellulose acetate production and purification, and manufacture of bioplastics. The characteristics of bioplastics was analyzed using some parameters such as density, tensile strength, elongation, Young's modulus, water absorption, biodegradability, compound group analysis using Fouier-Transform Infrared Spectrometer (FTIR) and bioplastic morphology analysis by using Scanning electrone microscopy (SEM). This study aimed to determine the effect of the plasticizer type and concentration on the bioplastics characteristics that was divided into several different concentrations of glycerol and sorbitol plasticizers (20%, 30%, and 40%). The fabrication of composite bioplastics used the cellulose acetat from kapok fiber, starch, and types of plasticizer (glycerol, and sorbitol). The results of the study showed that the addition of different plasticizers, such as glycerol and sorbitol gave distinct effects on the bioplastics product characteristics. The optimum concentration of glycerol addition affected the bioplastic characteristics with the best results were 40% concentration generate density of 0.836 g/mL, tensile strength of 0.818 MPa, water absorption value of 22.23%, and degradation plastic mass about 39.7%. The addition of sorbitol also affected the bioplastic characteristics, where the best results were 40% concentration produced bioplastic density of 0.941 g/mL, percent elongation at 3.94%, young’s modulus of 0.726 MPa, and degradarion mass of 32.05%. The morphology of bioplastic showed the high homogeneity on concentrations of 40% glycerol and 30% sorbitol.

Addressing the environmental impact of agro-industrial waste, this study explores the transformation of banana, potato, and orange peels into bioplastics suitable for thin coating films. We prepared six extracts at 100 g/L, encompassing individual (banana peel, BP; orange peel, OP; and potato peel, PP) and combined [BP/OP, BP/PP, and BP/OP/PP] formulations, with yeast mold (YM) medium serving as the control. Utilizing the spin-coating method, we applied 1 mL of each sample at 1000 rpm for 1 min to create the films. Notably, the OP extract demonstrated a twofold increase in bioplastic yield (860.33 mg/L) compared to the yields of BP (391.43 mg/L), PP (357.67 mg/L), BP/OP (469.40 mg/L), BP/PP (382.50 mg/L), BP/OP/PP (272.67 mg/L), and YM (416.33 mg/L) extracts. Atomic force microscopy analysis of the film surfaces revealed a roughness under 8 nm, with the OP extract recording the highest at 7.0275 nm, whereas the BP/OP mixture exhibited the lowest roughness at 0.2067 nm and also formed the thinnest film at 6.5 nm. With R2 trend values exceeding 0.9950, the films exhibited water vapor permeability values ranging from 3.05 × 10-3 to 4.44 × 10-3, with the OP film being the least permeable and the BP/PP films the most permeable. The OP film demonstrated the lowest solubility in both water and ethanol with values of 64.71 and 1.05%, respectively. The solubilities of all films were above 60% in water and below 4% in ethanol. Furthermore, the films exhibited antimicrobial efficacy against both Gram-positive and Gram-negative bacteria. Our findings confirm the potential of utilizing banana, orange, and potato peels as viable substrates for eco-friendly bioplastics in thin-film applications.

The increasing environmental concerns associated with petroleum-based plastics have driven the global interest toward biodegradable and sustainable alternatives. Bioplastics, that are biodegradable and/or produced from biological materials/renewable feedstock, have gained attention over the past few decades. Among the renewable resources, microalgae, such as Spirulina have been merged as promising candidates due to their rapid growth rates and no arable land usage (as compared to terrestrial feedstock). However, its limited mechanical performance restricts broader application. This study addresses that challenge by incorporating natural-based plasticizers, the glycerol and natural latex, into Spirulina -polyvinyl alcohol (PVA) films. Results showed that Spirulina improved tensile strength and biodegradation but reduced elongation. Latex-plasticized films exhibited the highest tensile strength (70 MPa) and elongation (17%), indicating stronger interfacial bonding and film integrity. Glycerol-plasticized films achieved 59 MPa tensile strength and 15% elongation. In biodegradation tests, glycerol-based films degraded faster, with 54.3% weight loss by day 15, while latex-based films showed 35.5% degradation, both outperforming pure PVA films. The findings demonstrate the potential of these algae-PVA composites, particularly those plasticized with latex, for replacing petroleum-based plastics in applications requiring moderate flexibility and high tensile strength.

Bioplastics are a solution to the food packaging problem, which generally uses synthetic petroleum packaging, which is increasingly limited, difficult to degrade by nature and a food safety solution for health. However, this packaging needs to be strengthened in its mechanical properties by adding chitosan and glycerol. This study aimed to investigate the effect of adding chitosan and glycerol on the physical dan mechanical characteristics of the bioplastics and the physical and mechanical characteristics of bioplastics resulting from adding different chitosan and glycerol. Design experiment using the factorial Completely Randomized Design (CRD) method with 2 (two) treatment factors and 3 (three) replications. The two treatment variables were chitosan concentration (0%, 1%, 2%) and glycerol concentration (1%, 2%, 3%) with three replications. There are 27 experimental units in total. The data obtained were analyzed using analysis of variance with a factorial Completely Randomized Design (CRD) model. If it has a significant effect, a further test with the least significant difference test at the 5% level is carried out. The addition of different chitosan and glycerol affected all parameters. Biodegradable plastic from Mulu Bebe banana peel starch with the addition of chitosan and glycerol plasticizer has the characteristics of water content 13.389-19.621%, density 0.047-0.112 gr/cm3, tensile strength 0.983-4.790 Mpa, elongation 1.402-13.317%, and water absorption 12.407-82.194%.

InformationTacca (L.Kunze) starch films (TSF), that are biodegradable were developed from the blending of plasticizers with tacca starch for possible use in food packaging.The effects of ingredient proportions (Starch level: 5-15g, Sorbitol plasticizer: 0-4.5g,Glycerol plasticizer: 0-4.5g) and Temperature: (75-95 0 C) on some physical (thickness, density, moisture content) and mechanical (Tensile strength and elongation) properties of the biodegradable films were investigated using Box-Behnken's experimental design in Response Surface Methodology (RSM).Linear regression models (thickness, density, moisture content and elongation) and quadratic models (tensile strength) were developed.Analysis showed that starch level significantly (p < 0.05) affected all the responses at 5% level of significance except for tensile strength (p > 0.05).Results also showed that plasticizer blends (both sorbitol and glycerol) had significant (p<0.05)effects on moisture content and the tensile strength of the biodegradable films.Also, there were interactive effects of the mixture ingredients and process temperature on the tensile strength of the biodegradable films.The plasticizers in combination, exerted significant (p<0.05)effect on the tensile strength of the biodegradable films at a 5% level of significance.The optimized values indicated that TSF prepared with 13.728g of starch, 4.5g of sorbitol, 4.5g of glycerol and 75 0 C of process temperature had improved and satisfactory response variable with a desirability value of 0.609.The Coefficient of determination (R 2 > 0.60) was obtained for each response variable and the plots showed a good correlation between experimental and predicted values, revealing the adequacy and fitness of the model.The optimal values obtained for the quality indices were 2.50mm thickness, 1.236g/m 3 density, 10.196% moisture content, 9.117MPa tensile strength and 29.047% elongation.The blending of different plasticizers with tacca starch helped to overcome the problem of brittleness associated with the use of tacca starch for films and made it attractive for the optimization of the films.

This study aims to compare the characteristics of mechanical and water vapor permeability of edible film based on low pectin methoxyl from cocoa skin with glycerol and sorbitol as plasticizer. In the research also added CaCO3 filler with the weight variation of 0; 0.2; and 0.4 gr. Pectin from cocoa peel was isolated by extraction use ammonium oxalic at a temperature of 85oC, pH of 3.6 for 60 minutes. An edible film synthesized at a temperature of 85oC to the agitation time of 50 minutes. 200 mesh of pectin used with the variation of glycerol and sorbitol plasticizer concentration are 1, 2 and 3% in volume. Edible films produced were dried at a temperature of 55oC for 6 hours. The results of the study obtained in 0.2 gr CaCO3 concentration and 1% glycerol of edible films has a tensile strength of 0.3267 mpa, percent elongation of 12.84%, modulus young of 2.5441 mpa, and the water vapor permeability of 4.1676 g/m2.day. While in 0.4 gr CaCO3 concentration and 1% sorbitol of edible films has a tensile strength of 6.511 mpa, percent elongation of 2.419%, modulus young of 269.119 mpa, and the water vapor permeability of 5.583 g/m2.day. Based on percent elongation characteristics, glycerol plasticizer made higher elasticity than sorbitol plasticizer. While the addition of filler able to increase tensile strength two times larger than without filler.

The optimization and modeling of the parameters, the concentration of polylactic acid (PLA), sugarcane bagasse cellulose fibers (SBCF), and snail shell nanoparticles (SSNP), were investigated for the development of bioplastic films. With the aid of the Box–Behnken experimental design, response surface methodology was used to assess the consequence of the parameters on the water absorption and thermal stability of fabricated bioplastic films. Varied water absorption and thermal stability with different component loading were obtained, evidencing the loading effect of snail shell nanoparticles and sugar bagasse cellulose fibers on bioplastic film’s water absorption and thermal stability. The quadratic polynomial model experiment data offered a coefficient of determination (R2) of 0.8422 for water absorption and 0.8318 for thermal stability, verifying the models’ fitness to develop optimal concentration. The predicted optimal parameters were polylactic acid (99.815%), sugarcane bagasse cellulose fibers (0.036%), and snail shell nanoparticles (0.634%). The bioplastic developed with optimized concentrations of each component exhibited water absorption and thermal stability of 0.45% and 259.7 °C, respectively. The FTIR curves of bioplastic films show oxygen stretching in-plane carbon and single-bonded hydroxyl bending in the carboxylic acids functional group. SEM and TEM images of the bioplastic showed dispersion of the nanoparticles in the matrix, where SSNP is more visible than SBCF, which may be due to the lesser loading of SBCF. The improved properties suggest an optimum concentration of naturally sourced resources for developing bioplastic, which may be used for food and drug packaging for delivery.

Water absorption in polymer blends such as starch-based bioplastic films is important to evaluate the stability characteristics of such films in water that will affect their long-term performance in final products. In this study, the absorbency of starch-based bioplastic films made from potato, cassava, and corn starches that have went through the hydrolysis process first to alter its characteristics and properties in terms of granular swelling and hydrophilicity behaviour. The final results showed that hydrolyzed cassava bioplastic film has the ability to absorb more water compared to hydrolyzed potato and corn bioplastic films. The reading of hydrolyzed cassava bioplastic film on the seventh day of immersion for all ratios were between 87.83 % to 131.29 %, while for hydrolyzed potato bioplastic films was 69.48 % to 92.41 % and hydrolyzed corn bioplastic films was 66.28 % to 74.18 %. Meanwhile, the density analysis was evaluated to determine its physical properties towards moisture condition. The results showed that the hydrolyzed cassava bioplastic films have higher density compared to the other two, which indicated that it is a more favourable raw material to produce biodegradable planting pot due to its ability to absorb more water. Hence, still manage to retain its shape with low brittle surface.

Natural fibre-reinforced polymer composites (NFRPCs) are preferred as alternatives for synthetic composites in aeronautical and automobile sectors due to their biodegradable characteristics. However, NFRPCs have drawbacks such as high water absorption and surface unevenness upon machining. Hence, various combinations of natural fibres and synthetic fibres are being explored. This chapter presents the mechanical and tribological properties of three NFRPCs. NFRPC laminates with 0.4 volume fraction (V f) of reinforcement (reinforcement: mixture of coir/sisal, coir/glass and sisal/glass) were fabricated by hand layup technique. Cardanol-based novolac resin was used as the matrix. The composite samples were evaluated for their water absorption, tensile strength and tribological properties. Scanning electron microscope (SEM) images of fibres reinforced with resin were analysed to understand the interfacial bonding between the resin and cell walls/lumens. Results indicate that sisal/glass fibre reinforcement showed higher tensile strength properties due to their combined strength, lower water absorption and better fibre–resin bonding. Amongst the composites, the coir/glass fibre reinforcement showed better wear resistance and lower friction force, when compared to the other combinations of reinforcements.