A theoretical development of the relationship between grafting and particle size on impact in two phase plastics

A new theory is developed which relates the graft level, graft molecular weight, and particle size to the probability of hitting a rubber particle as a crack propagates in a two-phase impact-modified plastic. It is shown theoretically that the particle size average of interest in evaluating the impact properties of two-phase plastics is the surface-average particle size D_s. The theory predicts a maximum probable impact at a specific particle size that depends on the graft level required to achieve compatibility between the two phases.