CO2/顺式-2,3-环氧丁烷交替共聚物的立体寡聚物合成及微结构分析  

Synthesis and microstructure analysis of stereoregular oligomers of CO2/cis-2,3-butene oxide alternating copolymer

作　　者：罗婧 孙星宇 王霞弟 周辉[1] 吕小兵[1] Jing Luo;Xingyu Sun;Xiadi Wang;Hui Zhou;Xiaobing Lü(State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学精细化工国家重点实验室,大连116024

出　　处：《科学通报》2020年第31期3418-3428,共11页Chinese Science Bulletin

基　　金：国家自然科学基金(21690073);教育部长江学者创新团队支持计划(IRT-17R14)资助。

摘　　要：聚合物主链的立体结构与其热力学性能密切相关.精确控制聚合物立体化学是配位聚合催化最重要的研究目标之一,而合成确定分子量的各种立构规整性寡聚物和它们的核磁碳谱分析是精确表征聚合物微结构的关键.本研究以手性2,3-丁二醇为起始原料,通过迭代合成方法,采用三光气为羰化试剂,制备了全同和间同结构的CO2/顺式-2,3-环氧丁烷交替共聚物(聚碳酸-2,3-丁烯酯)的四聚体和八聚体,并从它们的碳谱信息精确分析聚碳酸-2,3-丁烯酯的微结构.发现全同聚合物的羰基、次甲基和甲基的核磁碳谱分别对应于154.12、75.23和15.71 ppm化学位移处,而间同结构聚碳酸酯的羰基、次甲基和甲基的核磁碳谱分别对应于154.09、75.07和15.51 ppm.The utilization of carbon dioxide(CO2)as a nontoxic,abundant,economical and renewable C1 building block for the production of valuable organic chemicals can contribute to a more sustainable chemical industry.In the chemical process using CO2 as a raw material,the synthesis of degradable aliphatic polycarbonates by alternating copolymerization with epoxides has attracted widespread attention.Notably,aliphatic polycarbonates with biocompatibility and biodegradability have gradually attracted great attention in the field of biomedicine in recent decades,since Inoue and co-workers first reported the copolymerization of CO2 and epoxides to produce biodegradable CO2-based polycarbonates by using heterogeneous catalyst in 1969.This method used non-toxic and inexpensive CO2 to replace the highly toxic phosgene in the traditional polycondensation as carbonylation reagent.Since then,many heterogeneous and homogeneous catalysts systems have been developed for this copolymerization.However,the commercial applications of aliphatic polycarbonates have very limited due to their poor thermal stability and the mechanical properties in comparison with polyolefins.Recently,the binary or bifunctional catalyst based on metal-salen complexes was found to be very efficient for this transformation in immortal polymerization mode,affording various polycarbonates with complete alternating nature,and excellent region-and stereo-selectivity.Along with the discovery of these highly stereoregular catalyst systems that can generate copolymers with high stereoregularity,study on the regiochemistry of epoxides ring-opening during the copolymerization and the stereochemistry of the carbonate unit sequence in the polymer main chain was also reported.The stereochemistry of a polymer significantly affects its physical property.For biodegradable polymers,e.g.,polylactide,the degradation rate of isotactic polymers is much slower than that of amorphous polymers due to the orderly arrangement of building units in the former.Additionally,the relative ste

关 键 词：CO2 聚碳酸酯 寡聚物 微结构分析 核磁共振碳谱 

分 类 号：TQ317[化学工程—高聚物工业]