Preparation of POE Graft Copolymer and Its Application of Toughening Modification for PA6

A series of grafted ethylene-octene copolymers using itaconic acid (ITA) and styrene (St) as grafted monomers (POE-g-ITA, POE-g-(ITA-St)) were prepared via melt grafting technique by twin screw extrusion. The structure of grafted copolymer was characterized by FT-IR. The monomer and initiator concentration and the percent content of St in grafted monomers were also explored in the effect on the graft ratio (GR) and melt flow rate (MFR) of POE-g-ITA. The GR of POE-g-ITA reached 1.36% when when the ratio of POE:ITA:DCP is 94:6:0.36, and the GR of POE-g-(ITA-St) reached 1.44% when the ratio of POE:ITA:St:DCP = 94:3:3:0.18. The compatibilizer POE-g-ITA was introduced into PA6/POE blend by twin screw extrusion. The mechanical properties and morphological structure were investigated. The results revealed that the impact strength of the PA6/POE blend containing 5 phr of POE-g-ITA was enhanced 12.78 times compared with pure PA6. The crystallinity (X _c) of PA6 phase increased gradually when the compatibilizer POE-g-ITA was introduced into PA6/POE blends, although the melting point (T _m) of PA6 phase had no obvious change. The interface between PA6 and POE phase became indistinct and the compatibility was significantly increased.