Influence of electron beam irradiation on the morphology and mechanical properties of styrene/butadiene triblock copolymers

The crosslinking of a styrene/butadiene triblock copolymer via electron beam (EB) treatment and its influence on morphology and mechanical properties were studied. Different doses were applied to study the effect on the modification of polybutadiene segments of the triblock copolymers whereby the highly ordered hexagonal packed type of the morphology of the block copolymers was not notably modified. However, the glass transition temperature of the soft phase was significantly shifted towards higher temperatures implying the crosslinking of the polybutadiene chains resulting in the decrease in the mobility of the corresponding chains. Moreover, the EB treatment of the copolymer significantly changed the tensile elongation at break, modulus and strength. The changes were attributed to the dose dependent crosslinking of the polybutadiene chains.