Preparation And Modification Of Poly L-lactic Acid Biodegradable Polymer Materials

In this paper, Poly (L-lactide) (PLLA) with different molecular massprepared by ring-opening polymerization and processing technique wasresearched. Large molecular mass poly(L-lactide) was synthesized byring-opening polymerization with the catalyst Sn(Oct)₂. The effects ofprepared method of L-lactide, catalyst, time and temperature on reactionwere researched. In order to improve the water affinity of PLLA andcontrol its degeneration speed, the lactide (LLA) was copolymerizedwith glycollide(GA). The animal experimentation of PLGA copolymernerve tube was done. A new technique was invented on processing PLGAwhich is solution extracting fiber spinning and the fiber orientedmoulding. The effect of processing condition of them was researched.Results showed that: the amount of catalyst, reaction time andreaction temperature have influence on the molar mass of Poly (L-lactide).The beat reaction condition is that amounting catalyst 12000:1 andreacting at the temperature of 140 for 24 hours. Increase of the GAproportion can simultaneously reduce the molecular mass and thebending strength of the copolymer. The proportion of GA shouldaccording to the material different request. The textile fiber cells of whitemouse were raised on PLGA membrane, after three weeks the cells arecovered with the PLGA membrane surface and the shape like pavingstone. So the biological compatibility of PLGA is perfect. The bestbending strength of 196.7MPa can be obtained at the temperature of 155and 110MPa pressure.