摘要
设计不同的催化体系或引发剂实现了α-亚甲基-β-丁内酯(MβBL)单体的区域选择性聚合,合成不同拓扑结构的聚酯.选用偶氮二异丁腈(AIBN)自由基引发剂,选择性聚合MβBL的α位上亚乙烯基双键,形成线形含有四元环内酯单元的聚酯.使用SalenAlCH3金属配合物催化剂,区域选择性在MβBL的酰-氧键断裂,生成双键保留以间同结构为主的结晶性线形聚酯.有机强碱是MβBL的高效开环聚合催化剂,获得以酰-氧键断裂为主的线形聚酯.而使用简单碘化钠催化MβBL开环聚合,形成以烷-氧键断裂为主的结晶性环状聚酯.
Regioselective polymerization ofα-methyleneβ-butyrolactone(M_βBL)to afford polyesters with various topological structures was achieved by the use of different catalysts or initiators.With azodiisobutyronitrile(AIBN)as initiator,polymerization selectively occurred at the C=C bond to produce linear poly(α-methylene-β-butyrolactone)(PM_βBL)with the remain ofβ-butyrolactone unit.Achiral Salen aluminum complexes afforded linear syndiotactic-enriched polyesters with controllable molecular weight and a narrow polydispersity,in which ring-opening polymerization selectively occurred at the acyl C-O bond of M_βBL and the C=C bond was remained.Strong organic bases,such as 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU),exhibited high activity for ring-opening polymerization of M_βBL under mild condition,affording linear polyesters.Simple sodium iodide mediated M_βBL polymerization predominately produced crystalline cyclic polyesters with a melting point of 145.4℃,in which the ring-opening mainly concerned the alkyl C_β-O bond cleavage.This study demonstrates that the synthesis of various topological materials with different properties can be achieved by regioselective polymerization of functional monomers with the exquisite choice of catalyst or initiator.
作者
许越超
周辉
吕小兵
Yue-chao Xu;Hui Zhou;Xiao-bing Lu(State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian 116024)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2020年第1期91-97,I0004,共8页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号21690073)
教育部长江学者创新团队支持计划(项目号IRT-17R14)资助项目
