双核异金属锰(Ⅲ)-碱金属(Ⅰ)配合物催化环酯类开环聚合反应研究  

Mn(Ⅲ)/Alkali-Metal(Ⅰ) Heterodinuclear Catalysts for the Ring-opening Polymerization of Lactide andε-Caprolactone

作　　者：王霖铎 张绪刚[1] 段然龙 边新超[2] Lin-duo Wang;Xu-gang Zhang;Ran-long Duan;Xin-chao Bian(Institute of Petrochemistry,Heilongjiang Academy of Sciences,Harbin 150040;Key Laboratory of Polymer Ecomaterials,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022)

机构地区：[1]黑龙江省科学院石油化学研究院,哈尔滨150040 [2]中国科学院长春应用化学研究所、中国科学院生态环境高分子材料重点实验室,长春130022

出　　处：《高分子学报》2024年第9期1179-1190,共12页Acta Polymerica Sinica

摘　　要：设计合成了一系列以氯为轴向基团的锰(Ⅲ)和碱金属(Ⅰ)为核心的大环双金属中心配合物催化剂,并通过基质辅助激光解吸飞行时间质谱(MALDI-TOF-MS)和元素分析对其结构进行了详细表征.该系列催化剂可以在环氧环己烷(CHO)存在下催化丙交酯(LA)和ε-己内酯(ε-CL)聚合.对不同的碱金属离子进行筛选和优化,以确保实现最佳的聚合效果.研究了配合物中不同的碱金属中心对其催化性能的影响,实验结果表明碱金属中心的引入改善了配合物的催化性能,表现出相较单核席夫碱锰催化剂更好的催化性能,配合物胺桥部分的空间位阻效应对其催化活性具有明显影响,同时,在外消旋丙交酯的立体选择性聚合中,这一系列的配合物催化聚合倾向于得到具有等规立构结构的聚合物,通过MALDI-TOF-MS表征了聚合得到的聚乳酸(PLA)的端基结构,说明这一系列双金属中心配合物在环氧化物存在下的原位引发机理.A series of large-ring metal coordination catalysts with manganese(Ⅲ) as the axial ligand and alkali metal(Ⅰ) as the core were synthesized in this experiment,and their structures were characterized in detail by matrix assisted laser desorption time-of-flight mass spectrometer(MALDI-TOF-MS)and elemental analysis.These catalysts can catalyze the polymerization of propylene glycolide(LA)andε-caprolactone(ε-CL)in the presence of cyclohexane oxide(CHO).We screened and optimized different alkali metal ions to ensure the best polymerization performance.The experimental results show that the introduction of alkali metal centers significantly improves the performance of the catalysts,far exceeding that of mononuclear Schiff base manganese catalysts.The steric hindrance effect of the amine bridge moiety of the catalyst on the reaction activity is also significant.We investigated the stereo-selectivity of the catalysts for monomers and conducted copolymerization studies using different LA isomers,finding that this catalyst is more prone to obtaining polymers with isotactic tendencies.The polymerization mechanism was further analyzed by using MALDI-TOF-MS spectrometer to analyze the end groups of the obtained PLA and assist in the study of the polymerization mechanism.Experimental studies show that the stereo-selectivity of the polymerization is achieved through a chain-end control mechanism.

关 键 词：双核异金属催化剂 聚乳酸 聚己内酯 开环聚合 非均相催化剂 

分 类 号：O621.251[理学—有机化学] O641.4[理学—化学]