Ca and Na bentonites were modified by addn. of dialkyl-diamidoamine lactate in aq. medium and used for reinforcing low-d. polyethylene (PE-LD) and ethylene/vinyl acetate copolymer (EVA) after compatibilization with corn. maleic anhydride-grafted lineary PE-LD or EVA. The homogenization was carried out either by calendering or by mixing. Neither the tensile strength nor elongation at break of the composites were higher than that of primary PE-LD or EVA.