有机磷腈盐/三乙基硼二元催化体系协同催化环氧化物与二氢香豆素的开环交替共聚

Ring-opening Alternating Copolymerization of Epoxides with Dihydrocoumarin Catalyzed by Phosphazenium/Et3B Binary Catalytic System

通过使用有机磷腈盐催化剂三[三(二甲氨基)亚氨基]氯化磷(P_(4)^(+)Cl^(-))与三乙基硼(TEB)组成的二元协同催化体系,实现了3,4-二氢香豆素(DHC)与多种环氧化物的开环交替共聚.系统考察了聚合温度和催化剂用量等因素对聚合活性和选择性的影响.研究结果表明,通过优化聚合反应条件,P_(4)^(+)Cl^(-)/TEB催化体系对多种环氧化物与DHC的开环交替共聚表现出较高的催化活性和选择性,避免了分子内酯交换等副反应.研究了反应动力学,利用核磁共振氢谱(^(1)H NMR),体积排阻色谱(SEC)和基质辅助激光解吸/电离时间飞行质谱(MALDI-TOF-MS)对聚合物结构进行表征,结果表明产物为端基明确、分子量可控的高度交替结构的醚酯共聚物.

The ring-opening alternating copolymerization(ROAC)of 3,4-dihydrocoumarin(DHC)with various epoxides was successfully achieved using a binary catalytic system consisting of tri[tris(dimethylamino)phosphora-nylidenamino]phosphonium chloride(P_(4)^(+)Cl^(-))and triethylborane(TEB).The impact of polymerization temperature and catalyst loading on the catalytic activity and selectivity of ROAC was investigated.The P_(4)^(+)Cl^(-)/TEB catalytic system was found to be highly efficient and controlled in the ROAC process,preventing the intramolecular transesteri-fication.This results in polyesters with high alternating structures,controlled molecular weights,and preserved functional groups fidelity.The effectiveness of the catalyst system is supported by kinetic investigations,proton nuclear magnetic resonance(^(1)H NMR)and size exclusion chromatography(SEC)spectra,as well as matrix-assisted laser desorption/ionization-time of flight-mass spectrometry(MALDI-TOF-MS)analysis.