Physico-mechanical and Electrical Properties of NBR Structure Foams

Nitrile butadiene rubber, NBR, structure foam of different apparent
densities was obtained by using different concentrations of foaming agent,
azodicarbonamide, ADC/K. The swelling factor in kerosene and benzene as a
function of time was measured to elucidate the structure of these foams. This
study was assisted by the current-voltage characteristics which were measured
under the effect of different ratios of compressions: 0%, 10%, 30%, 40%, 50%
and 60%. Under Joule heating limit, deviation of conductivity from Ohmic type
of conduction, detected before, was observed as a result of compression. Shape
factor, free current carrier mobility, and the equilibrium concentration of
charge carrier in the conduction band were produced as functions of
compressive strain. The conduction mechanism was found to follow the
conventional band approach.