Effect of Butylamine Modified Kenaf Fibre on the Properties of Natural Rubber Compounds and Vulcanizates

Abstract

Filled compound prepared via typical rubber compounding or wet masterbatch method. Wet masterbatch prepared by mixing a filler dispersion in a latex. Filler dispersion stability is crucial, and a stable dispersion is hypothesized to result in lower filler structure and subsequently better reinforcement of the filled vulcanizate. Stable dispersion has greater repulsive forces among the particles. In this study, kenaf fiber (KF) will be dispersed in a polar medium; i.e. butylamine. The dispersion stability and KF particle size with respect to the ball milling time shows longer ball milling time results in finer KF particle size due to higher surface charges from butylamine. Zeta potential concluded that the dispersions are stable. The masterbatches of KF then compounded using two-roll mill to incorporate curatives and anti-degradants. The results showed longer scorch and cure time were reported with the ball milling time. This might be due to higher hydroxyl groups from KF. The decrement of maximum and delta torque with ball milling time is correlated with crosslinked density. Better tensile strength, elongation at break, tear resistance and abrasion resistance were reported with longer ball milling time. Ball milling time does not affect the stiffness and hardness of the filled vulcanizates. By comparing the filled vulcanizates prepared from wet masterbatch and typical rubber compounding method, the former has better reinforcement but lower crosslink density and less stiff, longer scorch time and cure time