Composites from SBR/PS blend and the chemically treated wood flour have been prepared. The materials used for such treatment are NaOH, MAN, MAN-glycidyl methacrylate, and silane coupling agent, used to improve the dispersion of wood flour in the SBR/PS blend. The effects of chemical treatment on curing characteristics, and physicomechanical and electrical properties of SBR/PS composites were studied. The rheological as well as the mechanical parameters were improved by using,the modified wood flour with MAN-glycidyl methacrylate (SMG), followed by SM obtained at 15 phr, while the other treatments slightly affect these parameters. The permittivity epsilon' and di-electric loss epsilon" were measured in the frequency range from 100 Hz up to 100 kHz and at temperatures ranging from 30 up to 90 degrees C. The dielectric investigations indicate that the samples containing wood flour treated with both SMG and SM increase the values of epsilon' and decrease those of epsilon", which allow such samples to be used in insulation purposes. The increase in the relaxation time and the crosslinking density v for such composites indicate the increase in filler-polymer interaction rather than filler-filler interaction. (c) 2006 Wiley Periodicals, Inc.