MECHANICAL PROPERTIES AND THERMAL CHARACTERISTICS OF POLY(LACTIC ACID) AND PARAFFIN WAX BLENDS PREPARED BY CONVENTIONAL MELT COMPOUNDING AND SUB-SUPERCRITICAL GAS- ASSISTED PROCESSING (SGAP)

摘要

In this study, poly(lactic acid) (PLA)/paraffin wax (PW) blends containing different amounts of PW were investigated. The blends were prepared by a twin-screw extruder in two ways: conventional melt compounding extrusion and sub-supercritical gas-assisted processing (SGAP). Then, these blends and the neat PLA were injection molded into ASTM 638 Type V tensile bars for evaluation. To observe the effects of the different melt compounding processes and the amounts of PW on the blends, the thermal stability and mechanical properties of the tensile bars were characterized. The results showed that the addition of paraffin wax changed the fractural mechanism and yielded tremendous improvements in elongation compared to neat PLA. In addition, samples made by the sub-supercritical gas-assisted processing (SGAP) extrusion exhibited better and more consistent results.