Mechanisms of Rubber Toughening

Abstract

How do small quantities of rubber produce such dramatic increases in the fracture resistance of brittle plastics? What is the mechanism of rubber toughening? The answer to these fundamental questions is far from obvious. The first satisfactory theory of toughening was advanced in 1964, almost 40 years after Ostromislensky' s original discovery, and 15 years after the commercial introduction of HIPS. Since 1964, the subject has developed to the stage at which quantitative theories can be constructed, but there are still many outstanding questions concerning the relationship between structure and fracture resistance. This chapter presents some of the qualitative and quantitative theories of rubber toughening, and discusses the problems that remain unresolved.