Model filled polymers. XIV: Effect of modifications of filler composition on rheology

Abstract

Abstract Steady shear vxiscosity, dynamic moduli and the appearance of fracture surfaces of model composites, consisting of monodisperse crosslinked polymeric spheres of varied composition in a polymethyl‐methacrylate matrix, depend on the compatibility of filler particle and matrix. After intensive mixing, “compatible” systems form uniform and stable dispersions. Filler particles cluster in incompatible composites producing a highly non‐Newtonian response. At 40 w% filler, yield behavior results, with a yield stress of 3100 Pa for polystyrene particles and 1900 Pa for copolystyrene‐acetoxystyrene particles. The flow properties of compositionally complex particles from seeding are determined by particle surface composition.