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 (EcobrasTM) 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.