Influence of carbon black on thermal properties and flammability of cross-linked elastomers

The paper presents the results of testing thermal properties and combustibility of butadiene-acrylonitrile rubber vulcanizates with different contents of bounded acrylonitrile: Perbunan NT 1845 and Perbunan NT 3945 from Bayer. The rubbers were cross-linked by means of dicumyl peroxide. Four types of carbon black with different specific surfaces were used as fillers. The test results were obtained with the use the derivatograph, DSC-204 of Netzsch, measurements of flammability by the method of oxygen index and in air. The results of measurements have shown that the thermal stability and flammability of the vulcanizates under investigation are affected by the activity of solid phase and the degree of surface development as well as the flexibility of polymeric chain and the degree of its unsaturation. A clear relationship has been found between the thermal properties and flammability of the cross-linked butadiene-acrylonitrile rubbers.