Fatigue, Resilience, Hardness, and Swelling Behaviour of Natural Rubber/Recycled Acrylonitrile-Butadiene Rubber (Nr/Nbrr) Blends

In the present study, the fatigue, resilience, hardness, and swelling behaviour of natural rubber and recycled acrylonitrile-butadiene rubber (NR/NBRr) blends were studied in the concentration range from 5 to 35 phr of recycled NBR. NBR gloves have excellent resistance to punctures, tear and many types of chemicals, while NR has good physical and mechanical properties. Blending NBRr into the rubber blends improved the processability, stiffness and resilience and conferred excellent oil resistance. The fatigue life of NR/NBRr blends decreased as the NBRr content increased, due to the incompatibility and poor dispersion of NBRr in the NR matrix. However, increasing NBRr content gave NR/NBRr blends better resistance towards swelling and hardness. Both properties increased due to the improvement in crosslink density when more NBRr was added, but the resilience properties exhibited an opposite trend. Scanning electron microscopy study indicated that the recycled NBR shows a coarser and poor dispersion in NR matrix particularly when more NBRr content was used, which leads to lower fatigue life of the NR/NBRr blends.