Melt polycondensation and analysis of hydroxyl-terminated poly(L-lactic acid) using small molecular diols as terminating agents

Jing Che*, Rong Jie Yang

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Citation (Scopus)

Abstract

The synthesis of hydroxyl-terminated poly(L-lactic acid) (PLLA) by direct melt polycondensation of L-lactic acid and use of small molecular diols as terminating agents was investigated. L-lactic acid was dewatered to prepare the dehydrated prepolymer at first. Then PLLA was prepared through melt polycondensation in a melt with catalyst system including TSA, SnCl2 and Sn(Oct)2. Finally, ethylene glycol, 1,4-butanediol, and 1,8-octanediol, respectively, were used in hydroxyl termination of the PLLA. The molecular weights and end-group structures of all products were characterized by gel permeation chromatography (GPC) and 1H-NMR. DSC and Disc Polarimeter were used to characterize crystallinity and racemization, respectively. The results show that two kinds of hydroxyl-terminated PLLA polymers were obtained: complete hydroxyl-terminated PLLA prepared by using ethylene glycol or 1,4-butanediol, incomplete hydroxyl-terminated PLLA prepared by using 1,8-octanediol or combination of two kinds of diols. Combination of ethylene glycol or 1,4-butanediol with 1,8-octanediol can reach high hydroxyl termination of PLLA, and maintain the molecular weight by decrease of alcoholysis at the same time. 1H-NMR was found as an effective estimating way for extents of reactions. The hydroxyl-terminating reactions of PLLA by the diols reduced the crystallinity and resulted in racemization to some extent.

Original languageEnglish
Title of host publicationMechanical Science and Engineering III
Pages890-894
Number of pages5
DOIs
Publication statusPublished - 2013
Event2013 3rd International Conference on Mechanical Science and Engineering, ICMSE 2013 - Hong Kong, China
Duration: 1 Mar 20133 Mar 2013

Publication series

NameApplied Mechanics and Materials
Volume328
ISSN (Print)1660-9336
ISSN (Electronic)1662-7482

Conference

Conference2013 3rd International Conference on Mechanical Science and Engineering, ICMSE 2013
Country/TerritoryChina
CityHong Kong
Period1/03/133/03/13

Keywords

  • Diols
  • Hydroxyl-terminated
  • Melt polycondensation
  • Poly(L-lactic acid)

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Che, J., & Yang, R. J. (2013). Melt polycondensation and analysis of hydroxyl-terminated poly(L-lactic acid) using small molecular diols as terminating agents. In Mechanical Science and Engineering III (pp. 890-894). (Applied Mechanics and Materials; Vol. 328). https://doi.org/10.4028/www.scientific.net/AMM.328.890