The work is devoted to the problem of increasing the interfacial interaction
of the components of polymer mixtures based on polyolefins by introducing nanodispersed silicon dioxide. This is due to the fact that a characteristic feature of most polymer mixtures is their thermodynamic incompatibility and an increase in interfacial interaction at the interface between the mixture components is the main condition for obtaining composite materials with improved properties. Nanodispersed silicon dioxide was obtained by dispersing Kove-los silicon dioxide in a mixture of toluene with isopropyl alcohol, and then the resulting organosol was mixed with polymer particles. Primary and secondary polyolefins - low and high pressure polyethylene -  were used as polymers. Samples were made by extrusion. Studies have shown that the introduction of nanodispersed silicon dioxide into a mixture of secondary polyolefins increases their mechanical strength by 71%, and the introduction of the same dioxide into a mixture of primary polymers increases the strength by only 52%. This is explained by the appearance in secondary polyolefins due to oxidative and mechanical destruction processes during their processing of
hydroxyl, peroxide, carbonyl and ether groups that provide interaction between oxidized fragments of polymer macromolecules and particles of silicon dioxide.