Ring-opening Polymerization of 2-Oxabicyclo[2.2.2]octan-3-one and the Influence of Stereochemistry on the Thermal Properties of the Polyesters

作     者：Tong Zhou Yu-Ting Guo Fu-Sheng Du Zi-Chen Li Tong Zhou;Yu-Ting Guo;Fu-Sheng Du;Zi-Chen Li

作者机构：Beijing National Laboratory for Molecular Sciences(BNLMS)Key Laboratory of Polym.Chem.&Physics of Ministry of EducationDepartment of Polymer Science&EngineeringCollege of Chemistry and Molecular EngineeringCenter for Soft Matter Science and EngineeringPeking UniversityBeijing 100871China 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：2022年第40卷第10期

页      面：1173-1182,I0008页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

基　　金：financially supported by the National Natural Science Foundation of China(Nos.21871014 and 21971005)。 

主　　题：2-Oxabicyclo[2.2.2]octan-3-one Ring-opening polymerization Stereochemistry Polyester Thermal properties 

摘      要：Polyesters with cyclic structures in the main chain typically possess superior mechanical and thermal properties together with chemical recyclability.Ring-opening polymerization(ROP)of bridged or fused bicyclic lactones is a simple,and in most cases controlled method to synthesize polyesters with alicyclic moieties in the polymer backbone.The stereochemistry of the alicyclic structures has a great effect on the polymer properties,which can be regulated by varying the polymerization conditions.Here,we report a systematic investigation on the ROP of 2-oxabicyclo[2.2.2]octan-3-one([2.2.2]VL)under different conditions.When initiated byn-butyl lithium(n-BuLi)or catalyzed by trifluoromethanesulfonic acid(TfOH)in the presence of benzyl alcohol,P[2.2.2]VLs containing all cis^(-1),4 disubstituted cyclohexane ring were obtained.However,P[2.2.2]VLs initiated by sodium methoxide(MeONa)or catalyzed by organic superbase contained both cis and trans isomeric structural units.The cis to trans transformation mechanism under these conditions was manifested,and the effect of stereochemical variations on the properties ofP[2.2.2]VLwas revealed.The stereoregularP[2.2.2]VLs,bothcisandtrans,exhibited higher crystallinity and melting temperatures(Tm)than those of the stereoirregular isomers.Finally,the degradation of P[2.2.2]VL with acid at high temperature could recover 3-cyclohexenecarboxylic acid.