MECHANICAL-PROPERTIES OF SURFACE-MODIFIED BAUXITE FILLED SBR VULCANIZATES .1.

The ultimate properties of rubber products are strongly influenced by the size, size distribution, structure, surface area and surface selec tivity of fillers. In this study, natural bauxite was coated with plas ma polymer (polystyrene or polybutadiene) to modify surface properties . The coated and uncoated bauxites were tested as filler for SBR vulca nizates, using static and dynamic mechanical methods. The fracture sur faces of the vulcanizates were investigated by SEM. Plasma polymer mod ified bauxite loaded materials showed appreciable changes in hardness compared with samples loaded with uncoated bauxite. It was concluded t hat surface selectivity plays a more important role than surface area for bauxite in the SBR vulcanizates.