Mechanical properties and microphase structure of hydrogenated S-SB-S triblock copolymers

We investigated the mechanical properties and microphase structure of a series of hydrogenated styrene-b-styrene-co-butadiene-b-styrene triblock copolymers with various degrees of hydrogenation (DHs). The results indicated a distinct increase in the tensile strength and modulus with increasing DHs. The results of dynamic mechanical analysis, transmission electron microscopy and small-angle x-ray scattering revealed that the segregation of the microdomain structure strengthened with increasing DHs. These results suggest that the enhancement of the mechanical properties with the DHs can be attributed to an increased segregation of the microdomain structure, which physically cross-links points on the hydrogenated SB matrix. The increased segregation of the microdomain structure can be attributed to the increased variation in the solubility parameters of polystyrene and hydrogenated SB segments with increasing DHs.