Interface in Styrene-Butadiene copolymers and blends: A Solid State 1H Determination

Pulse low resolution H-1-NMR was used to characterize commercial experimental transparent styrene-butadiene (SB) block copolymers, high impact polystyrene and blends. The free induction decay (FID) shows the presence of two components: the first, fast decaying, is due to polystyrene, while the second, slow decaying, is due to the interface and to polybutadiene. This last FID component shows the presence of two T1 relaxations; they have been interpreted respectively as due to the interface material and to the pure rubbery polybutadiene. A fast method for the study of SB copolymers and blends is proposed.