Anionic Polymerization of 1,3-Cyclohexadiene: Reactivity of Poly(1,3-cyclohexadienyl)lithium

✍ Scribed by Itaru Natori

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 160 KB
• Volume: 207
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200600371

✦ Synopsis

Abstract

Summary: The reactivity of poly(1,3‐cyclohexadienyl)lithium (PCHDLi), as a species for the propagation of the anionic polymerization of 1,3‐cyclohexadiene (1,3‐CHD), was examined using a post‐polymerization reaction of PCHDLi and 9‐bromofluorene (9‐BFL). The degree of nucleophilicity of the PCHDLi systems was determined as PCHDLi/1,4‐diazabicyclo[2,2,2]octane (DABCO) > PCHDLi/N,N,N′,N′‐tetramethylethylenediamine (TMEDA) > PCHDLi. The nucleophilicity of PCHDLi was strengthened by the complexation of TMEDA to Li, and was saturated when the TMEDA/Li molar ratio was over 1.0. The rate of polymerization increased with increasing nucleophilicity of PCHDLi. In addition, the molar ratio of the 1,2‐addition (1,2‐CHD unit)/1,4‐addition (1,4‐CHD unit) seemed to be strongly affected by both the nucleophilicity of PCHDLi and the steric hindrance of CLi bonds in PCHDLi.

Post‐polymerization reaction of poly(1,3‐cyclohexadienyl)lithium (PCHDLi) and 9‐bromofluorene (9‐BFL).

magnified imagePost‐polymerization reaction of poly(1,3‐cyclohexadienyl)lithium (PCHDLi) and 9‐bromofluorene (9‐BFL).