Epoxidation of Styrene/Butadiene Star Block Copolymer by Different Methods and Characterization of the Blends with Epoxy Resin

摘要

A star shaped polystyrene-block-polybutadiene-block-polystyrene (SBS) block copolymer was subjected to epoxidation reaction using different reagents such as m-chloroperoxy benzoic acid (MCPBA), peracetic acid (PAA), performic acid (PFA) and hexaflouro-isopropanol (HFIP). All the methods led to the targeted modification of the block copolymer satisfactorily, some of them also accompanying rapid side reactions. The epoxidized polymer was then blended with epoxy resin comprising diglycidyl ether of bisphenol-A in presence of methylene dianiline (MDA) as hardener. The mixing of the epoxidized block copolymer into the epoxy resin led to the formation of well dispersed uniform blend morphology and imparted enhanced thermostability and ductility to the blends. A brittle-to-ductile transition was observed in the blends.