Synthesis and Characterization of Interfacial Agents to be used in Polyamide 6/Rubber Blends

Polyamides PA have poor impact resistance at temperatures below Tg particularly in the dry state. This inconvenience can be eliminated by incorporating in polyamide matrix a rubbery toughening agent. To improve the adhesion between the phases, minimize the interfacial energy, and influence the dimension of the dispersed rubber particles, a third component, such as a graft or block copolymer of appropriate chemical structure, can be added to such PA/rubber blends. These copolymers are generally referred to as "interfacial agents"1. Suitable interfacial agents for PA/rubber blends can be preformed and then added to the homopolymers to be blended or can be formed in situ by chemical reactions during the mixing process. In both cases it is necessary to modify the rubbery polymer in order to introduce appropriate functional groups along the ch ain2-6. In this paper we report on the preparation of a functionalized ethylene-propylene random copolymer (EPM) and on the synthesis of EPM-g-PA 6 graft copolymers utilizing the functionalized EPM. Preliminary results on the use of modified EPM rubbers in PA 6/EPM blends have been previously reported.