Oil Resistance of Dynamically Vulcanized Poly(Vinyl Chloride)/Nitrile Butadiene Rubber Thermoplastic Elastomers.

SummaryDynamically cured poly(vinyl chloride)/nitrile butadiene rubber (PVC/NBR), thermoplastic elastomers (TPEs) were melt mixed at 150°C at 50 rev.min. ^-1 with a Brabender Plasticorder. Curatives concentration was varied from 0 to 1 phr in order to study the effect of dynamic curing on the oil resistance of the plastified formulations. The compounds were characterized in respect to their mass swell, tensile properties, tear strength and hardness. The PVC/NBR formulations have been exposed to air and oil under otherwise identical conditions. The influence of oil and thermo-oxidative ageing on the mechanical properties were characterized at room temperature and 100°C. It was found that at ambient temperature the samples immersed in oil possessed similar properties to those that were exposed to air. Profound enhancement in mechanical properties were observed for both environments at 100°C. The observed scenario has been attributed to the increase in the degree of curing which was accompanied by a steady reduction in % mass swell with increased sulfur loading. The excellent mechanical behavior of the PVC/NBR TPEs even after immersing the samples in oil at 100°C evidenced for the good oil resistance of the materials. [ABSTRACT FROM AUTHOR]