Chem. J. Chinese Universities ›› 2017, Vol. 38 ›› Issue (1): 133.doi: 10.7503/cjcu20160619

• Polymer Chemistry • Previous Articles     Next Articles

Correlation of Transesterification Between Poly(lactic acid) and Poly(propylene carbonate) on Catalysts

ZHANG Min, ZHANG Shuyang, LIU Zhengying, YANG Wei, YANG Mingbo*()   

  1. State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China
  • Received:2016-09-01 Online:2017-01-10 Published:2016-11-11
  • Contact: YANG Mingbo E-mail:yangmb@scu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.51473105, 51033003).

Abstract:

Stannous octoate[Sn(Oct)2] and tetrabutyl titanate(TBT) were selected as transesterification catalysts to investigate the transesterification of poly(lactic acid)(PLA)/ poly(propylene carbonate)(PPC) blends. From the gel permeation chromatography(GPC) and 1H nuclear magnetic resonance(1H NMR) results of pure PLA, PPC under the catalysis of Sn(Oct)2 or TBT, it was found that PLA mainly had chain scission under Sn(Oct)2 catalyzing while intramolecular transesterification under TBT catalyzing. PPC mainly showed chain scission, mostly in high molecular weight molecule chains, under two kinds of catalysts, and the catalysis activity of TBT was more effective than that of Sn(Oct)2. Considering the transesterification of PLA/PPC catalyzed by Sn(Oct)2, TBT or composite catalyst[Sn(Oct)2/TBT], respectively, a certain extent of transesterification under any catalyst would be realized, accompanied by chain scission. PLA/PPC with Sn(Oct)2 or Sn(Oct)2/TBT was given priority to chain scission rather than transesterification, but TBT could promote the transesterification mainly. Due to the chain scission of neat PPC under any single catalyst mostly happened in high molecular weight molecules chain, a lower transesterification degree could be obtained when the mass ratio of PLA/PPC was 1:1, which would be a good guidance to further improve the degree of transesterification between PLA and PPC.

Key words: Poly(lactic acid), Poly(propylene carbonate), Transesterification, Chain scission, Composite catalyst

CLC Number: 

TrendMD: