Elastomer composites containing layered fillers and hydroxyapatities

M. Lipinska, J. Pietrasik, M. Zaborski, A. Masek
Institute of Polymer and Dye Technology, PL

Keywords: composite, elastomer, hydroxyapatites, layered fillers

Summary:

Carbon black is commonly used as a filler for rubber. It is an active filler able to reinforce and improve the properties of finished rubber products. For ecological and economic reasons research activity has been focused on looking for new methods of surface modification of inactive fillers to enhance their strengthening performance as alternative fillers for elastomers. Unmodified montmorillonites are incompatible with most polymers. It is necessary to modify them in order to increase layer-spacing and to facilitate the penetration of polymer chains. The modification involves introducing various organic cations in place of sodium cation naturally present between layers. In our study hydroxyapatites were also used as elastomer fillers. Surface properties of modified fillers, the zeta potential of suspended solids in the water, the oil absorption number, the impact of modifications on the tendency to agglomerate in the non-polar and polar medium were investigated. The modified fillers were used in elastomer matrices with different polarity: the ethylene-propylene copolymer EPM and acrylonitrile-butadiene rubber XNBR. The effect of the application of fillers on the cross-linking density of the vulcanizates, and on rheometric and mechanical properties of filled systems was investigated. Ageing studies (thermal, atmospheric and under UV radiations) were also conducted.