Studies on Mechanical, Thermal, Physical Properties and Characterisation of PLA-EVA Blend with Microclay and Product Development

M Selvam; S Soundararajan; S. K. Nayak

Abstract

PLA-EVA (70:30 wt. %) with microclay (1, 3, 5 wt. %) was also melt blended using Glycerol (1%) was used as compatibilizer in a twin screw compounding extruder. Then test specimens were prepared by an injection molding machine. Mechanical, thermal and physical properties were evaluated. As microclay content was increased, the tensile strength, elongation at break and tensile modulus were slightly decreased but higher than that of PLA-EVA (30 wt. %) blend but lower than that of poly lactic acid (PLA). Also flexural strength, flexural modulus, izod notched impact strength and hardness were increased when compared to PLA-EVA (30%) blend. In the thermal properties heat deflection temperature (HDT) increased and melt flow index (MFI) decreased. Scanning electron microscope (SEM) shows the Ethylene-vinyl acetate (EVA) is partially compatible since EVA was dispersed as bubbles in PLA matrix and two phases were observed. DSC also shows the melting point of PLA at 154.75°C and Tg of PLA at 59.92. EVA has melting point at 124.27°C. Product like trays were molded easily after predrying in hot air oven from PLA-EVA blend with microclay.

Abstract

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