Friedel-Crafts alkylation reaction of vinyltri-methoxysilane with styrene was performed in the pres-ence of anhydrous AlCl3. Alkoxy(4-vinylphenethyl)silane has been obtained. The synthesized products were identified by 1H, 13C, COSY NMR, and FTIR spectroscopy. Calculations using the quantum-chemical non-empirical density functional theory (DFT) method for the reaction between vinyltrimethoxysilane and styrene performed for ortho-, meta- and para-positions were discussed. For the theoretical modeling an online prediction program "Priroda 04: A quantum-chemical program suite" was used. Composite materials based on wood sawdust with various dispersion qualities and synthesized trimethoxysilylated styrene as a binding and reinforcing agent with degrees of silylation (5 %), in the presence of various organic/inorganic additives, fire retardants, and antioxidants, have been developed at different temperatures and pressures via hot press method or extrusion. The physico-mechanical properties of composites have been investigated.