Effects of a quaternary ammonium salt on the properties of carbon‐black‐filled natural rubber compounds

The effects of a quaternary ammonium salt, cetyltrimethylammonium maleate (CTMAM) on the curing characteristics and mechanical properties of carbon‐black‐filled natural rubber compounds are determined. Results indicate that CTMAM increases the rate of vulcanization to a maximum at 1 phr (part per hundred parts of rubber) followed by a decrease as the concentration of CTMAM is further increased. The incorporation of CTMAM also improves mechanical properties such as tensile and tear strengths, tensile modulus, hardness and resilience, whilst elongation at break shows a decreasing trend. CTMAM also improves filler dispersion and increases the extent of crosslinking of carbon‐black‐filled natural rubber compounds. © 2001 Society of Chemical Industry