The effects of the addition of alkanolamide on carbon blacks filled natural rubber compounds

The effects of the addition of alkanolamide (ALK) on cure characteristics and filler dispersion of the two types of carbon black (CB) filled natural rubber (NR) compounds were investigated. The N-550 and N-220 types of CB were utilised, and each of them was incorporated separately into NR compound with a fixed loading, 30.0 phr. The ALK was synthesized from Refined Bleached Deodorized Palm Stearin and diethanolamine; and incorporated into the CB filled NR compounds as an additive ingredient. The ALK loadings were 3.0, 5.0, 7.0 and 9.0 phr. It was found that ALK could function as a secondary accelerator and also an internal plasticiser. As a secondary accelerator; ALK decreased the scorch and cure times of the N-550 and N-220 CBs filled NR compounds. The higher the ALK loading, the shorter the scorch and cure times. As an internal plasticiser; ALK decreased the minimum torque and improved the dispersions of both types of CB in NR phases. At a similar ALK loading; N-220 exhibited higher cure rate, minimum and maximum torques and torque difference values. However, degree of filler dispersion of N-220 was poorer.