Living anionic polymerization of ethylphenylketene: A novel approach to well-defined polyester synthesis

✍ Scribed by Atsushi Sudo; Satoshi Uchino; Takeshi Endo

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 212 KB
• Volume: 38
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(20000401)38:7<1073::aid-pola4>3.0.co;2-y

✦ Synopsis

A living polymerization of ethylphenylketene (EPK) was accomplished. When polymerization of EPK was carried out with butyllithium as an initiator in tetrahydrofuran (THF) at Ϫ20 °C, EPK was completely consumed within 5 min, and the corresponding polyester with narrow molecular weight distribution (M w /M n ϳ 1.1) was obtained almost quantitatively. Kinetic study of the polymerization at Ϫ78 °C revealed that conversion of EPK agreed with the first-order kinetic equation, and that M n of the polymer increased in virtually direct proportion to the conversion. Along with these results, successful results in postpolymerization at Ϫ20 °C strongly supported living mechanism of the present polymerization. Further, lithium alkoxides having a methoxy group, styryl moiety, and nitroxyl radical, also successfully initiated polymerization of EPK to afford the corresponding polymers having functional initiating ends. In the polymerization with varying feed ratio [EPK] 0 /[initiator] 0 , the linear relationship between the feed ratio and M n of the obtained polymer was observed, while maintaining narrow M w /M n .