Polylactic Acid Synthesis And Characterization

In this paper, poly(lactic acid) was synthesized by indirect method. It included the synthesis of lactide, the purification of lactide, the polymerisation of lactide and the polymer's analysis and so on.Stannous caprylate was selected as the catalyst. Under certain vacuum, we investigate the relation of both the dose of catalyst, the temperature of reaction, the time of reaction and the molecular weight of the PLA.Furthermore we investigate how the purity of lactide and the circumstance of vacuum affect the molecular weight of the PLA.The properties of two types of the PLA(PDLLA,PLLA) were characterized by DSC, TGA, SEM, POM and GPC. It included cell compatibility, tissue compatibility, degradability and molecular weight.The result shows that through adjusting the reactive conditions, we get the weight-average molecular weight of poly(D,L-lactic acid) attains to 150,000 and the weight-average molecular weight of poly(L-lactic acid) attains to 3 80,000 . PLA has good cell compatibility and tissue compatibility. The thin membrane of PLA was embeded in the rabbits and the rabbits had a good condition of growth. There are no complication in the rabbits. The material of PLA with good surface activity can provide the interface and the micro- environment for growth of the cell. The molecular weight and crystallization affect the degradation rate of the PLA either in or out the body. And in the body the degradable velocity was more fast.