Cure Characteristics and Ageing Resistance of Recovered Waste Pre-Vulcanized Nitrile/Epoxidized Natural Rubber Latex Blends in Nitrile Butadiene Rubber Compounds

Waste pre-vulcanized nitrile latex (WPNL), obtained from nitrile glove dipping tank was blended at different ratios with concentrated ENR latex processed via ultrafiltration and designated as ENRLC-SP20 and ENRLC-SP50, respectively, with the number indicating, the percentage of WPNL incorporated into the blend. The blends were prepared in the latex stage and subsequently processed into dry rubber. The rubbers were then blended with virgin nitrile rubber (NBR) at various ratios and the curing characteristics and physical properties of the blends were evaluated. The results showed the maximum torque (MH) decreases while the minimum torque (ML) increases with increasing level of SP 50 rubber. Using higher concentrations of SP-50, the results showed slight reductions in the cure (t90) and scorch time (ts2), respectively. It was also found that by increasing ratio of ENRLC-SP20 and ENRLC-SP50 improves the heat ageing resistance of NBR blends at 100°C as evidenced by the higher percentages in retention of the blends, compared to the control compound.