Lanthanide Thiolate Complexes: Novel Initiators for Ring-opening Polymerization of ε-Caprolactone

✍ Scribed by Hong-Mei Sun; Huan-Rong Li; Chang-Sheng Yao; Ying-Ming Yao; Hong-Ting Sheng; Qi Shen

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 114 KB
• Volume: 23
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.200591541

✦ Synopsis

Abstract

The ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) using lanthanide thiolate complexes [(CH~3~C~5~H~4~)~2~Sm(μ‐SPh)(THF)] ~2~ (1) and Sm(SPh)~3~(HMPA)~3~ (2) as initiators has been investigated for the first time. Both of 1 and 2 were found to be highly efficient initiators for the ROP of ε‐CL. The poly(ε‐caprolactone) (PCL) with molecular weight M~n~ up to 1.97×10^5^ and relatively narrow molecular weight distributions (1.20< M~w~/M~n~<2.00) have been obtained in high yield in the temperature range of 35–65 °C. According to the polymer yield, 2 showed much higher activity than 1. However, the number‐average molecular weight of PCL obtained with 2 was much lower than with 1. The possible polymerization mechanism of the ε‐CL polymerization has been proposed based on the results of the end group analysis of the ε‐CL oligomer.