The Study Of Silk Fibroin Copolymerization Modify Poly(L-lactic Acid)

Poly (lactic acid) (PLA) is one of the most important environmental friendly polymers because of their biodegradability,renewable resources, and excellent properties. PLA polymers can be employed as a promising cost-effective alternative to commodity petrochemical-based plastics so as to lessen the dependence of plastics on oil and diminish the pollution caused by waste plastic products.Silk fibroin (SF) can improve the bioco MPatibility of PLLA. But poly(lactic acid) also exists many defects, such as the bad hydrophily, short of the cell identification signal and the bad cell affinity and so on. These defects restrict the PLA's application on the cell's matrixes of organization engineering and the medical postpones explaining system.The silk fibroin (SF) with the endophilicity to the human body cell can be used to modify PLA materials to enhance the biological compatibility of PLAs.In this paper, PLLA and SF were polymerized through melt copolycondesation with Sn(Oct)2 as the catalyst, it was employed for the characterization of polymers with Viscometry, polarimetry, FT-IR,DSC,GPC,X-ray,and NMR,detected the effects of hybrid method,micro structure,molecular weight,and discussed the affect of PLA's structure and performance for blend method and the proportion of material .The result indicates that:Optical purity and molecular weight of copolymer were changed with reaction conditions with Sn(Oct)2 as catalyst to solid polymerization;the best reaction conditon is 6 hours reaction time,150℃temperature,PLLA/SF for 6/1,and 0.5 % (wt)catalysts.In this paper, LLA and SF were polymerized through ring-opening copolymerization with Sn(Oct)2/naphthalene disulfonic acid as the catalyst system.it was employed for the characterization of polymers with Viscometry, polarimetry, FT-IR and DSC,and detected the effects of hybrid method, reaction time, temperature, catalyst weight.The result indicates that: Sn(Oct)2/naphthalene disulfonic acid as catalyst systems is suitably to ring-opening polymerization; the best reaction conditon is 6 hours reaction time,180℃reaction temperature, 4/1 for LLA/SF , 0.5 % (wt)catalysts,and 1:1 for the proportion of catalysts.All in all, PLLA and SF were polymerized through solid polymerization with Tin salt as catalyst to prepare copolymers; and LLA and SF were polymerized through ring-opening polymerization Tin salt / proton acid as catalyst systems to prepare copolymers,which will deduce PLA cost and lessen the pollution of solvents during its process.