Characterization of Blends of Virgin Nitrile Rubber and Compounded Nitrile Rubber Latex Waste Reclaimed with Urea: Part II - Physico-Mechanical Properties

Recycling of rubber waste materials in order to convert these to usable products is one of the main challenges in the rubber industry. Reclaiming of rubber waste and blending it with virgin rubber have increased during the past due to the growing concern on the environment and increase in the prices of synthetic rubbers. Hence, the aim of this study is to partially replace virgin nitrile rubber (NBR) with reclaimed compounded NBR latex waste to develop new rubber blends suitable for special applications. In this study, physico-mechanical properties, ageing performance and swelling behaviour of virgin NBR / reclaimed NBR blend vulcanizates were evaluated and compared with those of the control vulcanizate produced solely with virgin NBR. Results showed that replacement of 50% virgin NBR with reclaimed NBR retained 71-86% of tensile strength, elongation at break and resilience. Hardness and modulus of this blend vulcanizate increased by less than 18%, whereas abrasion volume loss and compression set increased by 27%. Ageing resistance is similar to that of the control vulcanizate. Interestingly, resistance to swelling in toluene and ASTM oil No.3 increased by 14% and 32%, respectively. Hence, the 50:50 virgin NBR / reclaimed NBR vulcanizate would be suitable for oil resistant applications.