Use of Acrylic Polymer Modified Hydrophobic Nano-Silica in Reinforcing of XNBR Nano-Composites

Carboxylated nitrile butadiene rubber (XNBR) latex is enjoying a big share in the glove manufacturing industry as the natural rubber latex gloves been found to contain some natural proteins which cause allergic reactions in certain individuals. The main problem associated with synthetic elastomers like XNBR is that they are typically not self-reinforcing. Therefore, addition of reinforcing fillers is a must in such lattices to meet application specifications. In the present study, poly(methacrylic acid) (PMAA) and poly(methacrylic acid & ethylhexyl acrylate) (60:40) (P(MAA-EhA)) modified nano-silica was used for reinforcement of XNBR. Evaluation of properties of XNBR vulcanizates filled with of micro silica, unmodified nano-silica, acrylic polymer modified nano-silica was carried out separately. The results show that addition of small quantities of nano-silica confers an increase of mechanical properties of XNBR vulcanizates, while high filler loadings of nano-silica decrease the mechanical properties due to the aggregation of nano-silica particles. The XNBR composites based on 5 phr of 2% PMAA and 1.5% P(MAA-EHA) surface modified nano-silica, showed the highest mechanical and swelling properties amongst all the modified fillers tested.