Investigation of the effect of thermal aging on rapid gas decompression (RGD) resistance of nitrile rubber

Thermal aging is possibly the most significant factor affecting the rapid gas decompression (RGD) resistance of rubber. In this study, NBR vulcanizates by different sulfur curing systems such as conventional (CV), semi-efficient (SEV), and efficient (EV) were thermally aged for 7 days at 100 °C. The effect of thermal aging on RGD resistance, and physico-mechanical properties has been evaluated by changes in the rating of RGD and properties before and after aging. The presented results show that thermal aging of NBR vulcanizates strongly depends on crosslink density and mechanical properties. Thermal aging of nitrile rubber samples increased the crosslink density and decreased tensile and tear strength which lead to lower RGD resistance. The significant changes of RGD resistance were in the CV > SEV > EV system order during aging. The results obtained indicate that the SEV system might be a suitable selection for engineering applications with middle physico-mechanical properties and good thermal aging and RGD resistance.