Enhancing Properties of Thermoplastic Starch/Natural Rubber Blends through the Synergistic Combination of PEG and Modified Natural Rubber

Abstract

Abstract This study focuses on enhancing the mechanical and thermal properties of thermoplastic starch (TPS) and natural rubber (NR) blends through the incorporation of polyethylene glycol (PEG 2,000) and various types of modified natural rubber such as epoxidized natural rubber (ENR), poly(methyl methacrylate) grafted natural rubber (NR-g-PMMA), and poly(butyl methacrylate) grafted natural rubber (NR-g-PBMA). The influence of TPS/NR blend ratios, PEG content, and type of modified NR on the properties of the blends was investigated along with their water absorption and bio-degradation. The increase in ductile properties of the TPS/NR blends can be achieved by increasing the NR content. Among the series of TPS/NR blends, the highest toughness (1,630 MJ/m3) can be observed when the blend was formulated from 1.0 wt% of PEG and 10.0 wt% of ENR. The water absorption of TPS/NR blends was found to be lower than the TPS sample, but still exhibited a high water absorption rate compared to the other conventional polymers. The bio-degradation test confirmed the bio-degradation capability of TPS/NR blends according to ASTM 5988-12, and the result revealed that more than 80% of the tested samples can be bio-degraded in soil within 90 days.