Effect of combinations of antimony trioxide with nontoxic flame retardants on the flame resistance and properties of vulcanized rubber based on general-purpose rubbers

The possibility of partial replacement of antimony trioxide by nontoxic flame retardants (Cloisite 15A organoclay, microquartz, Cloisite 15A + microquartz and aluminum hydroxide + barium borate combinations) was examined for vulcanized rubber based on general-purpose isoprene (SKI-3) and butadiene (SKD) rubbers. The rheometric, physicomechanical, and thermal properties and the flame resistance of vulcanized rubber samples containing various flame retardants were studied. Combination of antimony trioxide with Cloisite 15A shows high performance as flame retardant owing to intercalation of rubber macromolecules into the interlayer space of the layered silicate, which is the base component of Cloisite 15A. The intercalation leads to a decrease in the diffusion of the degradation products and to deceleration of the rubber combustion. Combination of antimony trioxide with the aluminum hydroxide + barium borate system also shows high performance as flame retardant owing to successive endothermic processes of decomposition of the formulation components.