Study on Catalytic Synthesis of Poly(L-lactic acid) from L-lactide

Under reduced pressure,Poly(L-lactic acid)(PLLA) has been synthesized by ring-opening polymerization of L-lactide(LLA) catalyzed by Sn(Oct)2.The influences of reaction temperature and time of polymerization,catalyst usage were investigated in detail.The results showed that the optimal value of viscosity average molecular weight can be obtained with reaction time of 64 h,reaction temperature of 150 ℃ and the ratio of catalyst to monomer 16 000.The polymer with a viscosity average molecular weight(2~12.6)×104 was fairly reproducible by optimizing the polymerization conditions.The structures and patterns of the polymer were characterized by DTA and SEM techniques,respectively.