Textile rubber biocomposites were prepared by the reinforcement of natural rubber with woven sisal fabric. The viscoelastic properties of the composites were analyzed at different frequencies. Sisal fabric was subjected to different chemical modifications, such as mercerization, silanation, and thermal treatment, and the influences of the modifications on the dynamic mechanical properties were analyzed. The storage modulus was found to increase with reinforcement of natural rubber with woven sisal fabric. The chemical modification of the sisal fabric resulted in a decrease in the storage modulus. The damping factor was found to decrease with chemical treatment, and the gum compound exhibited maximum damping characteristics. The thermal stabilities of the composites were also analyzed by thermogravimetric studies. Scanning electron microscopy studies were performed to evaluate the morphology of the fabric matrix interface. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 614-621, 2010