Preparation and characterization of nitrile butadiene rubber-nanoclay composites with maleic acid anhydride as compatibilizer. Part I

Abstract

Nitrile butadiene rubber (NBR)-nanoclay composites have been prepared. Maleic acid anhydride-treated organoclay (MOC) was synthesized and utilized as a compatibilizer. The prepared clay structures were analyzed by Fourier transform infrared (FTIR) spectroscopy. Furthermore, the FTIR investigation confirmed the incorporation of (MOC) in the NBR matrix, X-ray diffraction analysis indicated that an exfoliated structure was obtained, and scanning electron microscope images displayed the good interaction between the MOC and the rubber matrix. The influence of the MOC content (i.e. 1, 3, 5, 10, 20 phr) relative to the micrometer clay (i.e. 10, 20 phr) on the NBR compounds was analyzed through rheometric and swelling characteristics. The rheometric study demonstrated an increase in minimum and maximum torques, delayed scorch time and optimum cure time for the MOC (3 phr)-incorporated NBR compound compared to pure NBR. The cure rate index followed the same trend. In addition, these particular compounds showed decreased equilibrium swelling in toluene solvent, increased crosslinking density, a greater volume fraction and bound rubber content compared to the corresponding rubber filled with micrometer clay.