Chemical Modification of Upgraded Bentonite as Filler of Natural Rubber/Organobentonite Composite

Bentonite is an abundant natural resource that has great prospects for used as filler in natural rubber industry after certain modification, either through physical or chemical process. Reduction of mineral impurities in the bentonite was done to form upgraded bentonite by using hydrocyclone, and chemical modification of upgraded bentonite to form organobentonite was done by addition of commercially surfactant. Natural rubber/organobentonite composites made by melting compound technique at roll mill. The results showed that the reduction process of mineral impurities in the bentonite had been able to reduce the content of impurities, such as Fe2O3, CaO, and K2O. Meanwhile, by using XRD dan FTIR analysis, an increase in the dose of surfactant on upgraded bentonite might increase the organic content and basal spacing of organobentonite. Low mineral impurities organobentonite was capable of producing natural rubber/organobentonite composite with faster vulcanization time and some better mechanical properties (such as elongation at break and modulus 100%) than natural rubber/carbon black composite.