The Physical and Mechanical Properties of Corn-based Bioplastic Films with Different Starch and Glycerol Content

Abstract

Petroleum-based plastics have had a long history with varied materials and applications. However, the major drawback with these plastics is their harmful impact on the environment. Poor disposal management of these plastics have ultimately affected humans. Therefore, starch-based bioplastics have been widely used because of their renewability, sustainability and cost-effectiveness. This work investigated the effect of different concentrations of corn starch (10%, 15%, and 20% w/w of distilled water) and glycerol (20%, 30%, and 40% w/v of corn starch) on the properties of corn-based bioplastic films. Particularly, mechanical (tensile strength, Young’s modulus and elongation at break) and physical (water absorption rate and moisture content) properties were investigated. These films were prepared by the solvent casting method. It was demonstrated that the addition of 30% glycerol produced mechanical properties closest to the standard value, while films with a composition of 15% of corn starch had the most optimised value. Meanwhile, 20% glycerol and 20% corn starch produced a film with high strength and stiffness but lacked flexibility. Higher concentrations of starch and glycerol produced the highest moisture and water absorption rate. This was due to the highly hydrophilic nature of both corn starch and glycerol. However, the concentration of glycerol needs to be adjusted based on the intended use of the film. In conclusion, the concentration of corn starch and glycerol produced slightly different outcomes. Thus, the properties and application of the cornbased bioplastic films can be maximised by optimising the concentration of corn starch and glycerol.

Physical, Mechanical and Antibacterial Properties of Biodegradable Bioplastics from Polylactic Acid and Corncob Fibers with Added Nano Titanium Dioxide

“…It was decreased when the concentration of PLA was decreased and the concentration of CF was increased. This similar result was found in the previous study which showed that increasing the concentration of starch caused a reduction of elongation of break [28]. In addition, decrease elongation at break of FG-plasticized films was occurred when the plasticizer concentration was increased [31].…”

“…This result is showed linear character with the physical and mechanical properties of corn-based bioplastics films with different starch and glycerol content, which demonstrated that the concentration of starch increased, with the increasing of tensile strength [28]. Furthermore, corn-based films with 10 % concentration of corn starch and glycerol possessed poor tensile strength at 0.5 MPa.…”

“…The mechanical properties, including tensile strength, elongation at break, and Young's modulus, of the bioplastics specimens were performed according to the conditional standard test method for tensile properties (ASTM D638) and an electronic universal testing machine (UTM) with a constant tension of 50 mm/min was employed. Determination of mechanical properties of the specimen was conducted as previous described [28,29] with slight modifications. The tests were established on 5 specimens for each sample.…”

Physical Properties of Thermoplastic Cornstarch/Hibiscus sabdariffa Fiber Obtained by Evaporation Casting

“…They reported that the addition of HS extract strengthened the hydrogen (H)‐bonding in the composites; therefore, the strengthened H‐bonding among the extract and chains, the steric hindrance, and the free volume between starch–starch chains were reflected in the decreased stiffness for all composites. [ 45,47,49 ] In our case, the HS fiber could mainly modify the starch–starch intermolecular interaction. There was strengthened H‐bonding among starch–HS fibers, with a reduction in the H‐bonding among the starch–starch fibers.…”

Pembuatan Plastik Biodegradable Pati Jagung Terplastisasi Sorbitol dengan Pengisi Selulosa dari Ampas Tebu

“…Pati sebagai bahan baku bioplastik memiliki keuntungan jumlahnya berlimpah, harga murah, dan dapat diperbaharui [4]. Namun, bioplastik berbahan dasar pati memiliki kekurangan yaitu bersifat tidak tahan air, rapuh, dan kaku [5].…”