EPDM composition filled with mixtures of aluminum hydroxide (ATH) and carbon black were evaluated for electrical applications. Aluminum hydroxide, known for its characteristics of flame retardancy, is a semi-reinforcing filler and, in this sense, it is unable to impart the reinforcement level necessary to several applications. Thus, to have in the same artifact the non-flammability properties together with a high mechanical performance, carbon black, the most widely used reinforcing filler, has also been used. The choice of EPDM can be justified by the availability of this polymer in the brazilian market, allied to its characteristics to accept large amounts of filler and its apolar chemical character, which is a basic requirement for application in electrical insulation. To meet the Brazilian Technical Standards - ABNT, mechanical and flammability tests were carried out in order to find out the relative amounts of the two fillers which would give the best balance of properties. Amounts as high as 160 phr of aluminum hydroxide are required to achieve good flame resistance.
EPDM compositions; aluminum hydroxide; flammability; mechanical properties
