Crystallization and Mechanical Properties of Low Molecular Weight Polyester Plasticized Polylactic Acid
Polylactic acid(PLA)is a high-modulus,high-strength biodegradable thermoplastic polyester used in the packaging,textile and medical industries.Conventional plasticizers are usually non-biodegradable,the study used low molecular polyhexanediol succinate(PHS)blended with poly(L-lactic acid)(PLLA)to obtain a fully degradable system.The compatibility,crystallization and mechanical properties of the blended system were investigated by differential scanning calorimetry,polarizing microscope and universal testing machine.The results show that the crystallinity of PLLA/PHS ratios of 100/0,95/5,90/10,85/15,and 80/20 were 7.5%,8.7%,11.5%,14.1%,and 14.2%,respectively.The crystallinity of the blends increased with increasing PHS content,indicating that PHS successfully promoted PLLA crystallization.In addition,the crystallization rate of 80/20 was increased 10-fold and the semi-crystallization time was halved compared to pure PLLA.The elongation at break of the blends increased from less than 10%for pure PLLA to about 60%(PHS content 20%),with a slight decrease in strength and modulus.The elastic modulus of the blends decreased continuously with the increase of the PHS content,from 2.25 GPa for pure PLLA to 1.86 GPa at 20%PHS content.
万方数据
维普
