Copolymerization of Isobutene with 4-(2-Hydroxyl-2-methylpropyl) Styrene Co-initiated by TiCl₄ in the Presence of ED

Abstract

The carbocationic copolymerization of isobutene with an inimer (initiator-monomer), namely 4-(2-hydroxyl-2-methylpropyl)styrene, in the presence of TiCl₄ as a co-initiator and external electron donors (EDs) in hexane and methane chloride mixture at −80°C were investigated. The GPC traces recorded by UV detector and the ¹H-NMR spectra of the copolymers demonstrated that the 4-(2-hydroxyl-2-methylpropyl)styrene could copolymerize with isobutene and homopolymerize carbocationically. The molecular weights of the polymers obtained by using 4-(2-hydroxyl-2-methylpropyl) styrene as an inimer are obviously higher than that of using 2-benzenyl-propan-2-ol as an initiator when all the other reaction conditions were kept the same. The molecular weight increased almost linearly with the evolution of the monomer conversion at the lower conversion and increased drastically at the higher conversion. The curve of the M¯ vs. conversion somewhat resemble the polycondensation.

Keywords:

• Isobutene
• 4-(2-Hydroxyl-2-methylpropyl)styrene
• Cationic copolymerization
• Branched polymer
• Electron donor

Acknowledgments

This work is based on research supported by the Foundation of Young Key Teacher of University of The Ministry of Education of the People's Republic of China.