Chitosan-reinforced nitrile rubber - a step towards sustainable development

This work aims to investigate the effect of chitosan powders on the mechanical, morphological and thermal behaviour of nitrile rubber (NBR). The chitosan content has been varied between 0 and 15 phr. NBR was initially loaded with chitosan using a two-roll mixing mill along with compounding agents and then cured by compression moulding using accelerated sulphur vulcanisation strategy. The results indicate that the mechanical properties of NBR increase at a critical loading of chitosan (12 phr). A new Chitosan Efficacy Index has been proposed to understand the effect of chitosan loading on overall mechanical properties. Morphological examinations by using scanning electron microscopy pointed towards the presence of voids and discontinuities within the fractured surfaces of the composites. Thermogravimetric analysis and water absorption studies have also been carried out to complement the results from the investigation of mechanical properties.