Synthesis and Properties of Hydroxytelechelic Polyisobutylenes by End Capping with tert-Butyl-dimethyl-(4-methyl-pent-4-enyloxy)-silane

Abstract

The low-activity cationic monomer tert-butyl-dime1hyl-(4-methyl-pent-4-enyloxy)-silane was synthesized by Grignard reaction and hydroxyl-protection reaction. Living polyisobutylene chains were initially synthesized by controlled cationic polymerization and then capped with tert-butyl-dimethyl-(4-methyl-pent-4-enyloxy)-silane. The hydrolysis of these polyisobutylenes end capped with tert-butyl-dimethyl-(4-methyl-pent-4-enyloxy)-silane gave rise to hydroxytelechelic polyisobutylene. NMR analysis confirmed that the hydrolysis was complete. Results also showed that a low polymerization temperature favored the participation of tert-butyl-dimethyl-(4-methyl-pent-4-enyloxy)-silane in the end-capping reaction. Moreover, polyisobutylene-based polyurethane exhibited greater acid resistance than commercial polyurethane.