Mechanochemical Reactions of Polymethyl Methacrylate and Polystyrene at High Pressures

Abstract

The mechanochemical reactions of polymethyl methacrylate and polystyrene were investigated at room temperature up to 15kbar static pressure by using a self-made high pressure apparatus capable of simultaneous shear deformation. Determinations of molecular weight and shearing stress of sheared sample confirmed that mechanochemical reactions proceed markedly in both polymer materials and the higher the static pressure, the more reactions proceed. The mechanochemical reaction rate and limiting molecular weight were evaluated by fitting the rate equation to experimental measurements on viscosity average molecular weight. We conclude that the mechanochemical reaction mechanism in deformed polymethyl methacrylate is somewhat different from that in deformed polystyrene. ESR data were also discussed.