PALM OIL FATTY-ACID AS AN ACTIVATOR IN CARBON-BLACK FILLED NATURAL-RUBBER COMPOUNDS - EFFECT OF VULCANIZATION SYSTEM

Carbon black filled natural rubber compounds were cured using conventi onal vulcanization (CV) and semi-efficient vulcanization (semi-EV) sys tems. The effect of palm oil fatty acid on cure characteristics and me chanical properties was examined. It was found that the cure time t(90 ), and scorch time increased with increasing palm oil fatty acid conce ntration in both systems. At fixed acid concentration, semi-EV compoun ds show shorter t(90) and scorch time than CV compounds. Results from tensile modulus, hardness, maximum torque-minimum torque M-HR-M-L, and swelling measurements indicate that palm oil fatty acid has some effe ct on crosslink density. At fixed palm oil fatty acid concentration, C V compounds have better mechanical properties (tensile modulus, hardne ss, tear and tensile strengths) compared with semi-EV compounds.