ZHU Kang-jie, LIN Xiang-zhou, YANG Shi-lin, LI Ye-bin, YI Hong-wei. SYNTHESIS OF PEG-PLA BLOCK COPOLYMERS AND DETERMINATION OF AVERAGE BLOCK LENGTHS BY 13C NMR[J]. Acta Polymerica Sinica, 1988,(4):258-263.
ZHU Kang-jie, LIN Xiang-zhou, YANG Shi-lin, LI Ye-bin, YI Hong-wei. SYNTHESIS OF PEG-PLA BLOCK COPOLYMERS AND DETERMINATION OF AVERAGE BLOCK LENGTHS BY 13C NMR[J]. Acta Polymerica Sinica, 1988,(4):258-263.DOI:
PEG-PLA block copolymers were synthesized using polyethylene glycol (PEG) and lac-tide (LA) in the presence of low toxic stannous octoate. The copolymer structure was determined by 13C NMR and the average block leng this were calculated. The results showed that LPKG was unchanged during the reaction process
but LPLA depended on polymerization time and LA content in the feed. This is in agreement with the character of step polymerization. The mechanism of polymerization was also assumed from experimental results.