MODIFIED ZINC SILICATE - AN ACTIVE RUBBER FILLER

Physico-chemical properties have been characterized for zinc silicates obtained in various conditions in reaction of sodium metasilicate solution with water soluble zinc salt (zinc sulphate or chloride). Attempts have been made to apply the precipitated zinc silicates in rubber mixtures based on butadiene-styrene rubber. Appropriate tests have been conducted. Also, a possibility has been tested of eliminating zinc oxide (an activator in the vulcanization process) from the rubber mixture. Studies have been presented on the modification of zinc silicate surface with silane and titanate coupling agents. The extent of surface modification has been estimated measuring heats of surface immersion and determining chemisorbed carbon on the surface which has originated from coupling agents. The effect of modifying zinc silicate surface has been evaluated by strength tests performed on vulcanizates filled with the modified silicates.