Proposed reaction routes of Ethylene-vinyl acetate (EVA)/Thermoplastic Polyurethane (TPU) Blends

Abstract

Blends of ethylene-vinyl acetate (EVA) and thermoplastic polyurethane (TPU) were prepared and their interfacial compatibility was improved with maleic anhydride (MA) by melt blending method. A coarse EVA/TPU blended morphology was turned into finer morphology by MA addition, which was confirmed by scanning electron microscopy (SEM), melt rheology and mechanical behavior. The processing torque of the blends increased with the addition TPU in EVA. Further, this value increased sharply when MA is added in the presence of DCP. The sharp increment of torque indicates a chemical reaction occurs with maleic anhydride with the help of free radical generator species. A possible reaction mechanism is proposed from all experimental results. So a thermodynamically stable and compatible blend of EVA/TPU could be possible by introducing MA and DCP and all these findings are strongly supportive and in favor of the proposed reaction route.