Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (10): 3203.doi: 10.7503/cjcu20210315

• Polymer Chemistry • Previous Articles     Next Articles

Living Ring-opening Polymerization of O-Carboxyanhydrides Catalyzed by Pyridine Derivatives

LI Chen, LI Yuesheng()   

  1. School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China
  • Received:2021-05-06 Online:2021-10-10 Published:2021-10-10
  • Contact: LI Yuesheng E-mail:ysli@tju.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21971188)

Abstract:

Poly(α-hydroxy acid)s can be synthesized by ring-opening polymerization(ROP) of O-carboxyanhydrides(OCAs) derived from α-hydroxy acids with rich side groups, which make up for the defects of poly(lactic acid) with restricted structure and performance. However, in the process of OCA ring-opening polymerization, chiral α-H is prone to racemization, which leads to the decrease of the stereoregularity of the polymer. Here, a high performance organic catalyst with simple structure, 4-methoxypyridine, is capable of rapid catalyzing the living ROP of OCA under the mild conditions, and effectively inhibits the side reactions of transesterification and racemization of chiral α-H to synthesize narrowly distributed poly(α-hydroxy acid) with high stereoregularity. In addition, although the ROP of OCA in common solvents such as toluene and tetrahydrofuran shows first-order kinetics, that in epoxy solvents follows 0-order kinetics, and the polymerization rate is independent of the monomer concentration. As a novel and efficient Lewis base catalyst, 4-methoxypyridine exhibits a great potential application value in the efficient synthesis of multi-block degradable polyester and preparation of polyester biological pharmaceutical carriers.

Key words: O-Carboxyanhydride, Poly(α-hydroxyacid), Ring-opening polymerization, Degradable polyester, Organocatalyst

CLC Number: 

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