Effect of NR/ABS Ratio on Mechanical, Dynamical and Morphological Properties of Vulcanized NR/ABS Blends

Abstract

Dynamically vulcanized NR/ABS blends by phenolic curing were carried out using an internal mixer at 180 °C. The effect of NR/ABS ratio (i.e., 50/50, 60/40, 70/30) on mechanical, dynamical and morphological properties was investigated. It was found that the tensile strength and hardness increased with an increase in ABS loading whilst the elongation at break decreased, indicating that the strength and hardness attributed to thermoplastic component whereas the elasticity of the blends contributed to the vulcanized NR. The results showed that the 60/40 NR/ABS blend provided the well-balanced mechanical properties. The storage modulus of thermoplastic vulcanizates (TPVs) increased with increasing contents of rubber. This is due to that a higher content of vulcanized NR domain was dispersed in the ABS matrix. The results agreed well with the tan δ and complex viscosity of the TPV at various blend ratios. SEM micrographs of 60/40 NR/ABS blend showed that vulcanized rubber domains were dispersed in a continuous ABS phase and it contributed to greater interfacial adhesion between the two phases and thus provided superior properties.