Role of in situ generated silica for rubber science and technology

Filled rubbers have a long history in rubber technology. Filler morphology in the rubber matrix significantly influences the performance of filled rubber products. Therefore, we have to achieve a certain morphology of filler in the rubbery matrix in order to enjoy good reinforcement. However, it has not been sufficiently known what kind of morphology is necessary for the reinforcement, because preparations of adequate models for the characterization of filler morphology have been difficult. The in situ silica filling of the rubber matrix can be modeled for the preparations. In this paper, the characteristic features of in situ silica generated in diene rubbers are reviewed, citing recent reports. Two important models are presented. One is a homogeneous silica filling in situ, producing soft rubber nanocomposites. The other is the formation of an in situ silica filler network, creating stiff rubber nanocomposites. The controlled in situ silica filling is useful to evaluate the reinforcement effect of filler in a rubber matrix. (c) 2016 Society of Chemical Industry