Influence of intumescent flame retardant and sepiolite on the mechanical and rheological behavior of polypropylene

The mechanical and dynamic-mechanical properties and the capillary rheological behavior of polypropylene (PP) containing an intumescent flame retardant and sepiolite nanoparticles are investigated. Previous studies demonstrated that the combination of 0.5 wt% of organically modified sepiolite (OSEP) with 12 wt% of flame retardant (ET) allows to obtain interesting fire properties. In this study it is shown that such combination also ensure an improvement of the mechanical properties with respect to both the neat resin and the corresponding binary formulations. This result may be related to the higher degree of crystallinity observed for this ternary formulation by DSC characterization. This advantages are obtained without worsening the processability of the hosting matrix.