Abstract:
The aim of this research was to prepare biodegradable polymer blends from LDPE, EBS wax and cassava starch. Various ratios of LDPE/EBS in the blends were 100/0, 90/10, 80/20, 70/30, 60/40 and 50/50. Each blend was mixed with cassava starch at the amount of 0, 33, 50 and 100 part per hundred of LDPE (phr). All the components were homogenized by twin screw extruder. Pelletized LDPE/EBS/starch extrudates were then formed into test specimens by injection molding machine. The effects of EBS wax and cassava starch on the mechanical properties, thermal behaviors, morphology, water absorption and biodegradability of the blends were investigated. The results revealed that adding EBS wax and cassava starch substantially improved the stiffness of the polymer blends. However, the tensile strength, elongation at break and impact strength of the specimens decreased with increasing EBS wax and starch portions. It was observed that flexural strength increased with increasing EBS wax content, but decreased as the amount of EBS wax was up to 50%. It was also found that the specimens prepared from 30 phr of starch exhibited higher flexural strength than those prepared from 50 and 100 phr. While adding EBS was and cassava starch insignificantly affected thermal behaviors, it significant improved water absorption and biodegradation of polymer blends.