Calamus deerratus fibre reinforced natural rubber vulcanizates

This research study investigates the potentials of Calamus deerratus fibre (CDF) as a reinforcing filler in natural rubber, Standard Nigerian Rubber (SNR10)   vulcanizates. The Calamus deerratus was cut, dried, pulverized, characterized and incorporated into the natural rubber compounds and the effects on the cure  characteristics and physico-mechanical properties of the CDF-reinforced natural rubber vulcanizates were determined. The results of the analyses, in comparison with a standard carbon black, CB(N330)-filled vulcanizates showed that the CDF manifested a reinforcing effect on the SNR10 vulcanizates but inferior to carbon black, N330-filled vulcanizates. The maximum torque, abrasion resistance, modulus, specific gravity and hardness increased while the scorch time, cure time,   elongation at break and rebound resilience decreased with increasing filler content. The cure time and scorch time were however higher in CDF-filled SNR10   vulcanizates compared to those filled with carbon black, N330. Tensile strengths of CB(N330)- and CDF- filled vulcanizates increased to optimum levels at 40 phr  and 30 phr respectively and decreased with increasing filler content. The results however showed that CDF imparted lower reinforcing potential as shown by the   lower tensile strength, abrasion resistance and modulus. The hardness results of the CDF-filled vulcanizates showed slight superiority over that of CB(N330)-filled vulcanizates.Keywords: Natural rubber, Calamus deerratus, fillers, reinforcement and vulcanizates

The reinforcing potentials of Velvet tamarind seed shell as filler in natural rubber compounds

This work focused on the development of a reinforcing filler from renewable natural plant resources as part of the ongoing search for environmental friendly fillers that will substitute synthetic reinforcing fillers such as carbon black and silica in rubber manufacturing. The cure characteristics, physico-mechanical and equilibrium swelling properties of natural rubber, Standard Nigerian Rubber (SNR10) vulcanizates separately filled with commercial grade carbon black (CB), N330 and pulverized natural plant material, Velvet tamarind (VT), seed shell were investigated. The results of the analyses showed that the scorch and cure times decreased while the maximum torques increased with increasing filler loading for both filled-SNR10 vulcanizates. The tensile strengths of both VT-filled and CB (N330) filled-SNR10 vulcanizates increased to 30 phr and 40 phr respectively and decreased with increasing filler loading. The modulus at 100% strain, specific gravity, abrasion resistance and hardness increased while elongation at break, equilibrium swelling and rebound resilience decreased with increasing filler loading for both filled-SNR10 vulcanizates. The results showed that Velvet tamarind seed shell manifested a reinforcing effect on the SNR10 compounds but lower than that of CB (N330) filler.Keywords: Natural rubber, fillers, reinforcement and vulcanizate properties