Chemical blowing agents in the rubber industry. Past – present – and future?

Whether it be foamed aluminium in the A-pillar of a passenger car, Ytong autoclaved aerated concrete, Elastolit PU rigid foam or Semperform EPDM window profile – whatever the class of materials, there will inevitably be foamed versions. Some of these are new while others have been established for decades, and they are used in a wide range of industrial and consumeroriented applications. Defined foam structures have therefore become an essential tool in modern materials development. This article outlines the technical aspects of chemical blowing agents and the special mechanisms by which they act, which lead to the targeted production of different elastomeric foams. In addition, it reports on the status of the current REACH discussion concerning the blowing agent azodicarbonamide.