Ion-irradiated butadiene acrylonitrile rubber reinforced with graphene filler

Abstract

The main objective of this work is to study the properties of a new generation of rubbers characterized by an increased strength of the material (by adding graphene flakes to carbon black used as a filler) and to improve the surface properties (by using ion irradiation as a surface treatment technique). Most of the results were obtained for an acrylonitrile-butadiene rubber (NBR) with about 40% weight content of carbon black/graphene filler. The results point that even a relatively small amount (a few wt%) of graphene flakes to carbon black filler leads to a significant increase of the rending resistance of the elastomer. Ion irradiation of pristine and/or graphene-doped elastomer leads to a drastic release of hydrogen atoms from the surface layer. In consequence a thin, carbon-rich layer is formed at the rubber surface. This layer is characterized by a high hardness (roughly ten times harder than the unirradiated material), an improved hydrophilicity and, what is most important, a 5–6 times lower friction coefficient and a drastically increased wear resistance. The ion-irradiated layer may act also as a protective barrier limiting the oxygen diffusion into the material bulk, hence leading to an improvement of the resistance to ageing of surface treated rubbers.