Novel graft copolymer EVA-g-PU: preparation and properties

Abstract

A new type of graft copolymer, EVA-g-PU, was synthesised via melt grafting. FTIR and ¹³C NMR testing showed that the polyurethane (PU) prepolymer was successfully grafted on ethylene-vinyl acetate (EVA) main chains. Mechanical testing showed that the tensile strength and elongation at break of EVA-g-PU was far superior to pure EVA. EVA-g-PU showed significant enhancement in shear viscosity. The enhanced storage modulus of EVA-g-PU was characterised by dynamic mechanical thermal analysis (DMA). The enhanced degree in the storage modulus of EVA-g-PU increased with the increase in PU prepolymer content. The thermal stabilities of EVA-g-PU were also studied by thermal gravimetric analysis (TGA). Scanning electron microscopy (SEM) showed that the EVA-g-PU matrix has excellent toughness characteristics.