The mechanical and electric performances of linear low-density polyethylene (LLDPE) highly loaded with aluminum hydroxide (Al(OH)(3)) by the grafting of methacrylic acid (MAA) to the LLDPE matrix were studied. The results of Fourier transform infrared spectroscopy showed that the grafting reaction occurred by melt grafting. Mechanical testing of composites of LLDPE highly loaded with Al(H)(3) showed that the strength and elongation at break were significantly improved after the grafting of MAA to the LLDPE matrix. The results of the electric tests showed similar trends. The results of scanning electron microscopy showed better decentralization of Al(OH)(3) loaded in the LLDPE matrix in the tensile fractured surface and a transition layer between Al(OH)(3) and the LLDPE matrix in the fractured surface after the grafting of MAA to the LLDPE matrix. (C) 2005 Wiley Periodicals, Inc.