Morphology evolution and dynamic relaxation behavior of solution-polymerized styrene-butadiene rubber/polyisoprene/silica ternary composites influenced by shear

摘要

The influence of SiO2 nanoparticles on the morphology evolution and rheological properties of solution-polymerized styrene-butadiene rubber/low vinyl content polyisoprene/nano-silica (SSBR/LPI/SiO2) ternary composites after cessation of various shear flows was studied by the combination of rheological and rheo-optical techniques. It was found that the nano-sized SiO2 acted as compatibilizer or filler and restricted the coalescence of polymer droplets under weaker shear flow, which led to less deformed droplets. Under stronger shear flow, the addition of SiO2 had no influence on the formation of string-like domain phase. After cessation of pre-shear flow, the presence of SiO2 nanoparticles did not change the relaxation mechanism of deformed domains, but retarded the breakup process of deformed domains and hindered the simultaneous coalescence of dispersed droplets by serving as compatibilizer or filler. It was proved that the SiO2 nanoparticles effectively reduced the droplet size and stabilized the morphology of SSBR/LPI blends. (C) 2018 Elsevier Ltd. All rights reserved.