Physical, mechanical, viscoelastic, and morphological properties of poly(lactic acid)/ethylene‐co‐vinyl acetate blend reinforced with silicon carbide nanoparticles

Abstract

AbstractPhase morphology, mechanical properties, melting and crystallinity, as well as the dynamic viscoelastic properties of poly(lactic acid) (PLA)/ethylene‐co‐vinyl acetate (EVA) (80/20) blend containing 0–3 wt% nano‐silicon carbide (SiC) were studied. Morphological observations revealed the localization of nano‐SiC particles around the EVA droplets with the consequence of a fall in the size of EVA dispersed phase in the nanocomposites compared with the unfilled blends. The mechanical characterization results showed a gradual increase in the elastic moduli and yield stress with increasing nano‐SiC content in the nanocomposites, while the strain at break and Izod impact strength were steadily decreased. The nano‐SiC particles served as nucleating agents for crystallization of the PLA matrix from the molten state. The crystallinity of the PLA matrix in the nanocomposites was slightly reduced compared with that of the unfilled blend. The dynamic mechanical thermal analysis results showed a gradual increase in the glass transition temperature of PLA matrix together with a steady decline of damping capability as the nano‐SiC content in the nanocomposite was increased. The dynamic rheological data demonstrated enhanced complex viscosities and storage moduli of the nanocomposites in a direct proportion to the nanofiller loading, specially at the low‐frequency region. The changes occurred in the various properties of the fabricated nanocomposites were interpreted in terms of alteration in the phase morphology and the physical interactions of the nano‐SiC particles with the blend's components.