LDPE modified with vinyltriethoxysilane and lactic acid and a natural bentonite organophilized with hexadecyltrimethylammonium bromide were used to extrude biodegradable nanocomposites contg. 4% bentonite and 30% lactic acid. Elongation-at-break and stretching strength were improved by 29% and 12% as compared with the starting composites. Microstructure examn. showed the polymer matrix to be more compact with the nanofiller added. The m.p. and the m. enthalpy of the nanocomposite were 114.7 degrees C (higher by 2 degrees C) and -134.2 J/g (higher by similar to 10 degrees/6), resp.