Diblock-Copolymer-Based Composites for Tire-Tread Applications with Improved Filler Network Topology

We present in this Letter the results of a study focusing on vulcanized poly(butadiene-styrene butadiene rubber) (PB-SBR) diblock copolymers in the microphase-separated state filled with various amounts of silica nano particles. It is demonstrated that the microphase separation of PB and SBR blocks is preserved in composites with a silica mass content of <= 60 parts per hundred rubber (phr). The only effect of silica incorporation is a more restricted long-range order of the block copolymer morphology. The most interesting finding is, however, that through mechanical mixing the silica nanoparticles are highly selectively incorporated in the SBR phase up to high filler contents. This opens new opportunities toward a rational design of the filler network in composites with self-assembled elastomer matrixes and results in advantageous mechanical properties for tire-tread applications.