Synergistic effects of cerium(IV) phosphate with intumescent flame retardant in styrene butadiene rubber

Abstract

Cerium(IV) phosphate [CeP(IV)] was synthesised by hydrothermal synthesis and used as a synergistic agent on the flame retardancy of styrene butadiene rubber (SBR)/intumescent flame retardant (IFR) system. The IFR system mainly consisted of ammonium polyphosphate and pentaerythritol. Limiting oxygen index, UL-94 test, thermogravimetric analysis, cone calorimeter, scanning electron microscopy and microscale combustion calorimeter were used to evaluate the synergistic effects of CeP(IV). The addition of CeP(IV) to SBR/IFR composites leads to the improvement in UL-94 values of the SBR/IFR/CeP(IV) composites, and the peak of heat release rate decreases with increasing CeP(IV) content. SEM was used to analyse the morphological structure of the residue chars formed from the SBR/IFR systems with and without CeP(IV). A possible mechanism for catalysing carbonisation was discussed. The experimental results indicated that there existed a synergistic effect between CeP(IV) and IFR for the flame retardancy of SBR.