Biocomposites based on Ecobras matrix and vermiculite

• VMT was modified with an alkyl-phosphonium salt through ionic exchange reaction.
• VMT and P-VMT were characterized by FTIR and TGA.
• Composites of Ecobras with 4 phr of VMT and P-VMT were prepared by melt blending.
• Composites were characterized by MFI, tensile test, biodegradability in soil and SEM.
• Composites with P-VMT showed higher young modulus and biodegradability rate.

Composites of biodegradable polymers with mineral fillers were studied to find environment friendly materials to be used in mechanically resistant and biodegradable articles. Composites based on polyester and starch matrix (Ecobras™) with vermiculite were prepared by the melt intercalation technique in a mixing chamber, followed by injection molding. Unmodified vermiculite (VMT) and vermiculite organically modified with tetrabutyl phosphonium bromide (P-VMT) were used in each composition. The mineral clay was characterized by Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The composites were characterized by melt flow index (MFI) measurements, thermogravimetric analysis and tensile mechanical tests. The biodegradation was evaluated using the simulated soil method (ASTM G 160), monitoring the mass loss and morphology. The P-VMT FTIR showed absorption bands indicating organic salt presence. The Young modulus, thermal resistance and biodegradation rate of the composite with 4.0 wt% P-VMT increased.