Rubber composites for sealing applications: effect of carbon nanotubes on material performance

In this paper the effect of MWCNTs on a commercial CB filled nitrile-butadiene rubber (NBR), having 60 degree of Shore A hardness, used for high performance sealant applications, was studied. The CB filled NBR was added via melt blending using an open two roll mill with different weight percentages of MWCNTs: 1%, 2%, and 4%. The material behavior was analyzed by different laboratory tests: standard mechanical characterization tests (hardness, compression set, uniaxial compression, tensile and stress relax-ation test) and thermal analysis were carried out. The material characterization was focused on the behavior of the composite material at medium-high deformation levels (from 10% to 30% of strain in compression), typical for elastomeric materials in sealing application conditions. The state of dispersion of MWCNTs was correlated with mechanical response of the final materials.