Abstract
One of the biggest dangers to our environment today is the increasing number of unused synthetic rubber in the environment and these pose a big threat to nature, if it is not disposed properly. Typically, synthetic rubber is developed for specific applications, and is specifically for those applications due to the process used to make them, and the resulting properties. Dumping these synthetic rubber in dumpsites could contaminate nearby water sources. Heating these synthetic rubber with normal heat will generate harmful chemical substances, like carbon and lead, which are really dangerous for humans. Dealing with rubber properly is not only advantageous to nature, but also to humans. Recycling represents a best alternative to the disposal of post-consumer rubber in common landfills if it is possible to obtain new materials with good final properties compatible with practical application. In this study, characterization and properties of virgin acrylonitrile butadiene rubber/recycle acrylonitrile butadiene rubber (vNBR/rNBR) were examined. Three different size ranges of rNBR particles, i.e., 150 - 350 mm, 2.0 -15.0 mm, and 5 -10 cm were used in this study. The vNBR/rNBR blends with blend ratios of 95/5, 85/15, 75/25, 65/35, and 50/50 phr (part per hundred rubber) were prepared using a two roll-mill at room temperature. The vNBR/rNBR blends with smallest size of rNBR particles show better tensile properties (tensile, elongation-at-break and M100) compared with all other blend ratios. For physical properties, vNBR/rNBR blends with smallest size of rNBR particles exhibited the highest hardness and cross-linking density at all blend ratios whereas resilience decreased, accordingly. The cross-linking density of vNBR/rNBR blends also show an increasing trend with increasing rNBR content. A morphological study of tensile fracture surface of the blends was also carried out. The scanning electron microscopy study indicates that rNBR exhibited a weak rNBR-vNBR matrix interaction particularly when more than 25 phr of rNBR was used, thus decreasing the mechanical properties of vNBR/rNBR blends. Keywords: vNBR, rNBR, Curing characteristic, Mechanical properties, Morphological properties