Optimization of mechanical properties of carrageenan-based bioplastic as food packaging

Abstract

Several types of plastic materials are widely used in food packaging because it has good mechanical and physical properties. However, the types of plastic used in food packaging, such as polyethylene (PE), polypropylene (PP), and polycarbonate (PC), are petroleum-based plastic that is not renewable, not biodegradable, and causes environmental pollution. One option to overcome this problem is to make bioplastic using renewable sources, one of which is carrageenan. Carrageenan is a polysaccharide used in bioplastic synthesis, but it has shortcomings in terms of mechanical properties. Thereby it needs additional supporting materials to improve its mechanical properties. This study aims to obtain optimal mechanical properties such as tensile strength, elongation, and modulus of elasticity. We optimized two variables in this study: glycerol concentration (1, 2, 3, 4, and 5%) and montmorillonite concentration (10, 20, and 30%). Optimization was carried out in two stages; the first stage was the optimization of glycerol concentrations, and the second stage was the optimization of montmorillonite concentrations. The optimum condition was obtained at 3% (v/v) glycerol and 20% (w/w) montmorillonite which gives a tensile strength value of 3.43 MPa, elongation of 47.01%, and Young Modulus of 7.31 MPa. Based on these optimization results, carrageenan-based bioplastic, especially on %EAB value, are comparable with other commercial plastic for food packaging.