Role of talc geomorphology on structural properties of bio-nanocomposites based on thermoplastic corn starch

CASTILLO, L.; LÓPEZ, O.; BARBOSA, S.; GARCIA, M.A.; VILLAR, M.

Porto do Galinhas

Congreso; XIV Latin American Symposium on Polymers (Simpósio Latino Americano de Polímeros ? SLAP). XII Ibero American Congress on Polymers (Congresso Ibero Americano de Polímeros - CIP).; 2014

Talc geomorphology effects on structural characteristics of thermoplastic corn starch (TPS) composites were studied. TPS films with talc nanoparticles were prepared by melt-mixing and thermo-compression. Talc formation process determines particles morphological characteristics. In this study, two talc samples having different geological origins and degree of impurities were used: platy and microcrystalline particles (98 % purity) and blocky and macrocrystalline particles (84 % purity). Scanning Electronic Microscopy (SEM) on composite films evidenced the morphological difference between talc samples. Besides, for both composites, particles orientation and a good filler distribution within TPS matrix were observed by SEM. Regardless talc geomorphology, X-Ray Diffraction (XRD) revealed that talc addition did not modify TPS crystalline structure neither its crystallinity degree. Composites analysis by Differential Scanning Calorimetry (DSC) determined that smaller TPS crystallites were induced by macrocrystalline talc particles respect to microcrystalline ones.