Characterization of Styrene-Butadiene Block Copolymers

Abstract

Commercially available styrene-butadiene block copolymers were studied t determine the block structure. The contents of polystyrene and the microstructure of polybutadiene parts in block cpolymers were determined by means of infrared spectrum method. Polystyrene parts were obtained by oxidative scission of polybutadiene parts in the block copolymers and the content of polystyrene was determined also by weighting. The contents of polystyrene in the block copolymers obtained by the above two methods agreed.Molecular weight of the block copolymers and polystyrene parts was mersured by gel permeation chromatography (GPC) method.From these results, the block structure of the block copolymers was estimated.