Flammability of butadiene-acrylonitrile rubbers

The paper discusses the test results of butadiene-acrylonitrile rubber, Perbunan NT 1845 and Perbunan NT 3945, flammability and properties that characterise these elastomers under fire conditions. The flammability was tested by means of oxygen index and thermovision methods. The thorough testing of flammability performed by means of a cone calorimeter made it possible to assess the behaviour of these polymers under fire conditions. The following properties of the tested copolymers were taken into account in this assessment: ignitability, heat release during combustion, smoke-forming capability and toxicity of the gaseous products of thermal decomposition and combustion. It has been found that the increase in the acrylonitrile unit content in the copolymer decreases its flammability and the relative toxic fire hazard, but clearly increases the smoke-forming capability and so the specific extinction area. The interpretation of test results of the elastomers under investigation takes into consideration their thermal stability assessed on the basis of differential thermal analysis, thermogravimetry and other complementary methods.