The Microstructure of Polyurethane (PU)/Ethylene-Vinyl Acetate (EVA) Polymer Lastomer of Analysis

EVA / PU are used as the polymer elastomer in this paper by the approach of graft copolymerization. By the scan analysis of EVA / PU flexible tensile fracture surface, it could be found, with the augment of EVA, the cross-section shows the transition from brittle fracture to ductile fracture, as well as a clear plastic deformation in the micro-fracture zone. The phenomenon of graft copolymerization between the EVA and PU can be observed by scanning probe micrograph . What’s more, while the height of the molecules increases，the molecules become increasingly small, indicating that the grafting reaction occurs between the free hydroxyl in EVAL and PU prepolymer.