Source Year: 2017

Carbon black filled natural rubber (NR) vulcanisate with known composition and properties were mechanically devulcanized by shearing in a laboratory two roll mill. The efficiency of devulcanisation was determined through crosslink density measurements. In order to simulate the end-of-life rubber products, mechanical devulcanisation of samples aged at standard laboratory conditions were also carried out. The devulcanized rubber prepared from un-aged and aged samples were incorporated in fresh compounds at three different proportions viz, 85/15, 75/25 and 60/40. A comparative study of such blends, where the filler present in the devulcanised rubber is also considered active and corresponding reduction is made in the formulation and the other case where the filler present in the devulcanized rubber is rendered passive, showed that there is a chance to optimize the vulcanizate properties of the blends of virgin rubber and devulcanized rubber by adjusting the compounding strategies. A combination of simple mechanical devulcanisation and optimization of the amount of filler while blending the devulcanized rubber with fresh compounds can give promising results.