Characterization and properties of natural rubber/styrene butadiene rubber/recycled acrylonitrile butadiene rubber (NR/SBR/rNBR) blends

Abstract

Utilization of recycled rubber in rubber blends preparation has provided the simplest and most cost-effective method in recycling discarded rubber products. The increasing demand for nitrile latex glove and it high consumption in current market resulted in abundance of used and waste nitrile gloves generated daily. Hence, discarded nitrile gloves, particularly the defects and rejects from the production processes, were utilized to develop new ternary rubber blends of natural rubber/styrene butadiene rubber/recycled acrylonitrile butadiene rubber (NR/SBR/rNBR). Firstly, NR/SBR/rNBR blends were prepared at different blend ratio of 50/50/00, 50/40/10, 50/30/20, 50/20/30, 50/10/40, 50/00/50, 40/50/10, 30/50/20, 20/50/30, 10/50/40, 00/50/50 (phr/phr/phr) by using tworoll mills at room temperature, and the characteristics and properties of the blends were investigated and compared. The next stages of the study are mainly aim to improve the tensile and physical properties of the blends by investigating the effect of different recycled acrylonitrile butadiene rubber (rNBR) particle sizes, compatibilization with epoxidized natural rubber (ENR 50) as compatibilizer and incorporation of different type of fillers on the blends. It is important to note the presence of unreacted accelerator in rNBR, detected from FTIR analysis. Generally, as the increasing rNBR loading in the blends (and the decreasing one of the virgin rubber constituent), the tensile and physical properties of NR/SBR/rNBR blends deteriorated. However, the highest tensile strength obtained by the optimum blend ratio of 50/30/20.