Evaluation of antimony-free flame retardants for pPVC synthetic leathers intended for safer automotive interiors

Antimony-based compounds have been the state-of-the-art flame retardants (FRs) for plasticized PVC (pPVC) due to their superior efficiency at very low loading. However, the use of antimony compounds poses more than an issue, for both human health and the environment, related to their extraction, processing and use. In order to follow the consequent need to phase out antimony compounds, different FRs for high-performance plasticized PVC (pPVC) synthetic leathers (SLs), intended for automotive interiors applications, have been selected amongst readily available on the market additives and tested in highly plasticized formulations. These FRs have been evaluated either alone or in combination in order to ascertain possible synergistic effects. The samples have been obtained with standard procedures used in the R&D laboratory of Vulcaflex S.p.A., and tested for thermal stability, mechanical and flame resistance, following standard and internal methods. Results have been then compared to those of a neat pPVC foil (DUP) and of a foil containing 2 phr of antimony trioxide (ATO). Amongst the alternatives tested, various combinations proved effective in improve flame retardancy without negatively affecting mechanical properties, and proving to be, thus, promising candidates to substitute ATO as FRs in pPVC materials.