| Abstract: | Dynamically vulcanized blends of nylon, styrene–acrylonitrile copolymer (SAN), and nitrile–butadiene rubber (NBR) were examined for mechanical properties, Shore D hardness, Vicat softening temperature, impact process, and phase morphology. The effect of a curing system such as phenolic formaldehyde resins (PF), dicumylperoxide (DCP), and a sulfur system on the mechanical properties of the nylon/SAN/NBR blends was studied, and dynamic vulcanization with a PF system was found to lead to outstanding toughness of the blends. The effect of PF content on the mechanical properties, Shore D hardness, and heat resistance of the nylon/SAN/NBR blends was also investigated. With increasing PF content the notched‐impact strength and Vicat softening temperature (VST) of the nylon/SAN/NBR (50/25/25) blends evidently improved, but tensile strength and Shore D hardness of the blends changed slightly. It can be concluded that the nylon/SAN/NBR (50/25/25) blends dynamically vulcanized by high‐content PF can attain excellent comprehensive mechanical properties, especially supertoughness, at room temperature. SEM was used to investigate the effect of dynamic vulcanization on disperse‐phase particle size, particle size distribution, and phase morphology. It was obvious that disperse‐phase particle size decreased with an increasing PF content. Thermal behavior and miscibility of dynamically vulcanized nylon/SAN/NBR with PF were investigated by DMTA. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2057–2062, 2003 |
