单脒基铝络合物催化己内酯聚合及己内酯/丙交酯共聚  

Polymerization of ε-Caprolactone and Copolymerization with rac-Lactide Catalyzed by Mono(amidinate) Aluminum Complexes

作　　者：钱峰[1] 刘克印[1] 马海燕[1] 

机构地区：[1]华东理工大学应用化学研究所金属有机研究室,上海200237

出　　处：《催化学报》2011年第1期189-196,共8页

基　　金：国家自然科学基金(20604009);国家重点基础研究发展计划(973计划;2005CB623801);教育部新世纪优秀人才支持计划(NCET-06-0413)

摘　　要：将单脒基铝络合物用于催化ε-己内酯(ε-CL)开环聚合反应,结果表明,该类铝络合物表现出很高的催化活性:25oC时络合物[{PhC(N-2,6-iPr2C6H3)2}AlMe2](C1)催化ε-CL聚合1h,单体转化率为91%;70oC时络合物[{PhC(N-2,6-iPr2C6H3)-(N-2,6-Me2C6H3)}AlMe2](C2)催化ε-CL聚合15min,单体转化率达100%.脒基N-芳环上取代基的引入能明显提高催化剂活性,N-芳环邻位双取代的单脒基铝络合物的催化活性高于邻位单取代的.所得聚合物的分子量大于理论值,且分子量分布较宽(PDI=1.43～1.85),说明聚合的可控度不高.单脒基铝络合物可通过先催化ε-CL聚合,再引发外消旋丙交酯聚合,得到聚己内酯和聚丙交酯的两嵌段共聚物.Mono（amidinate） aluminum complexes showed high catalytic activity for the ring-opening polymerization of ε-caprolactone in toluene at ambient temperature.Monomer conversion up to 91% could be reached within 1 h when using [{PhC（N-2,6-iPr2C6H3）2}AlMe2]（C1） as initiator at 25 ℃.The electron-donating groups on the ortho-positions of the N-substituted phenyl ring were superior to the elec-tron-withdrawing groups for the enhancement of the catalytic activity,but both brought an increase in activity when compared with the un-substituted complex C7.The complexes bearing two ortho-substituents on one of the N-phenyl rings were more active than the analogues bearing one ortho-substituent.Although high molecular weight poly（ε-caprolactone）s were obtained by using these aluminum catalysts,the polymerization of ε-caprolactone was not well controlled as indicated by the broad molecular weight distributions（PDI=1.43–1.85） and the deviation of the number average molecular weight from the theoretical values.Sequential copolymerization of ε-caprolactone and rac-lactide using mono（amidinate） aluminum complexes afforded poly（ε-caprolactone）-poly（rac-lactide） diblock copolymer,which was characterized well by NMR spectroscopy and gel permeation chromatography analysis.

关 键 词：脒基铝络合物 Ε-己内酯 外消旋丙交酯 开环聚合 共聚 

分 类 号：O643.32[理学—物理化学]