Preparation and Properties of Blends of Thermoplastic Polymer with Thermoplastic Starch

Haydar Zaman; Ruhul A. Khan

Abstract

Problems in making biodegradable plastics are incompatible between hydrophilic/polar and hydrophobic/non-polar ingredients. Ingredients like compatibilizers were added to improve the compatibility between the two ingredients. The purpose of this study was to determine the effect of thermoplastic potato starch (TPS) content and two compatibilizers (maleic anhydride, MA, and dibutyl maleate, DM) on melt flow behavior, mechanical features (tensile, bending, and Izod impact test), phase morphology, thermal behaviors (DSC, and TGA/DTG), and biodegradability of LDPE/TPS composites. The morphological structure of biodegradable plastics is compatible and uniform with the marked spread of TPS in the polymer matrix. The compatibilizer can mediate between two components whose properties are different, namely LDPE (hydrophobic) and TPS (hydrophilic). Biodegradable plastics have been made more compatible, and homogeneous and have better mechanical properties using a compatibilizer. Compatibilizers can develop surface adhesion between LDPE and TPS mixtures. The presence of DM in LDPE/TPS composites gives rise to excellent dispersion of potato starch in the matrix and improved properties compared to other composites which indicate homogeneity. Mechanical test results show that as the amount of TPS increases, the tensile modulus, flexible strength and modulus of uncompatibilized composites begin to increase, but the tensile strength and impact strength gradually decrease. The addition of compatibilizers further enhances the mechanical properties of the composite. In addition, DSC, thermal stability, and biodegradability were performed for different LDPE/TPS composites. Besides, water absorption of LDPE/TPS composites was reduced through the addition of compatibilizers.