White rice husk ash-filled natural rubber compounds: The effect of bondingagents

White rice husk ash (WRHA)-filled natural rubber compounds were prepared by using a laboratory-size two-roll mixing mill. Curing using a conventional vulcanization system was used and cure studies were carried out on a Monsan to rheometer. The mechanical testing of the vulcanizates involves the deter mination of tensile properties, tear strength, hardness, and resilience. Sc anning electron microscopy (SEM) and swelling measurement were also done. T he effects of bonding agents on the curing and mechanical properties have b een investigated using resorsinol formaldehyde and hexamethylene tetramine as the bonding agents. Results show that the bonding agents prolonged the c ure time t(90) and scorch time t(2) and, at the same time, improved the mec hanical properties of the natural rubber vulcanizates. SEM and swelling stu dies indicate that the rubber-filler interaction is improved with the addit ion of bonding agents,