Synthesis of Dihydroxy Poly(ethylene-co- butadiene) Oligomers via Metathetical Depolymerization

摘要

Telechelic oligomers found important applications as precursors for polymeric networks and for the production of block copolymers. Among these systems dihydroxytelechelic polybutadiene (PBHT) is widely used in polyurethane industry owing to its good elastomeric properties, very low glass transition temperature, resistance to hydrolysis and excellent dielectric properties. However both 1,2 and 1,4 butadiene units suffers from a relatively important and rapid aging process. With the aim to improve stability by decreasing the number of backbone insaturation, we investigated the synthesis of dihydroxy- telechelic poly(ethylene-co-1,3-butadiene) (PEB) as an alternative route to PBHT. Functionalized ethylene-butadiene oligomers were synthesized via metathetical depolymerization of high molar mass PEB in presence of first generation Grubbs catalyst and butene diacetate as functionalizing chain transfer agent (CTA). Chain ends are then hydrolyzed to obtain dihydroxy PEB oligomers (Scheme 1).