The effect of alkanolamide addition on cure and tensile properties of unfilled natural rubber compounds

Abstract

Effect of alkanolamide (ALK) addition on cure and tensile properties of unfilled natural rubber (NR) compounds was investigated. The ALK was synthesized from Refined Bleached Deodorized Palm Stearin (RBDPS) and diethanolamine, and incorporated into the unfilled-NR compound as a new rubber additive. The ALK loadings were 0.2, 0.4, 0.6, 0.8 and 1.0 phr. It was found that the addition of ALK exhibited shorter scorch and cure times and higher elongation at break of the unfilled NR compounds. The ALK also exhibited higher torque differences, tensile modulus and tensile strength of up to 0.6 phr of ALK loading and then decreased with further increases in the ALK loading. Scanning electron microscopy (SEM) proved that 0.6 phr loading of ALK in the NR compounds exhibited the greatest matrix tearing line and surface roughness which correlated to a higher tensile strength of the NR compound.