EFFECT OF INTERFACIAL CHAIN STRUCTURE ON TOUGHENING BEHAVIOR IN RUBBER-MODIFIED POLY(METHYL METHACRYLATE)

Core-shell composite particles were prepared by a heterocoagulation an d annealing process, in which control of the number of chemical linkag es in the interfacial zone without changing other properties was possi ble using five kinds of small size shell particles (SP) with different carboxyl charge density and one large size core particle (LP) with an epoxy functional group. These functional groups were capable of assoc iating with one another through chemical reaction by thermal treatment . With increase of surface functionality of SP, the toughness was foun d to be higher. This indicated that a higher number of interfacial lin kages between core and shell materials resulted in an increase in the critical stress intensity factor K-k of the modified poly(methyl metha crylate) (PMMA) composite. The interfacial properties between core and shell phase therefore play an important role in the impact behaviour of composite materials.