Synthesis of PLLA-b-PCL Copolymer by Coupling Reaction of Hydroxyl-end PLA Oligomer with PCL Prepolymer

摘要

In our previous paper, [1] we have reported a novel process to prepare PLLA-b-PCL by direct melt polycondensation PLLA, and then by coupling reaction between HO-PLA-OH and Poly(s-caprolactone)(PCL) prepolymer with -NCO end group, whereas the average-number molecular weight(Mn) of PLLA oligomer is rather low To obtain higher Mn of PLLA oligomer which is advantage for copolymerization, a special process to synthesis PLLA prepolymer with hydroxyl teminatated have been developed in this paper, which can obtain rather high molecular weight of PLLA oligomer and reduced the content of small molecular simultaneously The hydroxyl terminated PLLA prepolymer and copolymer (PU) were carefully characterized with FTIR , GPC, DSC. The results indicated that the molecular weight of PLLA-b-PCL copolymer can be up to 230,000g/mol.