Bipyridine-phenolate based aluminum complexes mediated ring-opening polymerization of epsilon-caprolactone and lactides with a high stereoselectivity

作者：Hsieh Yi Liang; Huang Ning; Lee Gene Hsiang; Peng Chi How^*

来源：Polymer, 2015, 72: 281-291.

DOI：10.1016/j.polymer.2015.02.026

• Bipyridine-phenolate
• Ring-opening polymerization
• Stereoselectivity

Aluminum complexes coordinated by bipyridine-phenolate (BpyPh) ligands of 2-([2,2'-bipyridin]-6-yl)-4,6-di-tert-butylphenol (BpyPh(2,4-tBu)-H), 2-([2,2'-bipyridin]-6-yl)-4-(tert-butyl) phenol (BpyPh(4-tBu)-H), and 2-([2,2'-bipyridin]-6-yl)-4,6-dimethylphenol (BpyPh(2,4-Me)-H) have been synthesized and applied to mediate the ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) and L-lactide (L-LA) in the presence of benzyl alcohol. The living characters of predictable molecular weight, narrow molecular weight distribution, and the formation of block copolymer were observed in the polymerization mediated by (BpyPh(2,4-tBu))AlMe2 and all three complexes associated with benzyl alcohol could initiate the ROP of epsilon-CL and L-LA. The iso-selectivity of rac-lactide polymerization could be enhanced from P-m = 0.38 to P-m - 0.75 by increasing the steric hindrance of ortho-substituent on phenol group of the ligand.

• 出版日期2015-8-18
• 单位清华大学