THE SYNERGISTIC EFFECT OF HYBRID FLAME RETARDANTS ON PYROLYSIS BEHAVIOUR OF HYBRID COMPOSITE MATERIALS

The aim of this investigation is to comprehensively understand the polymeric composite behavior under direct fire sources. The synergistic effects of hybrid flame retardant material on inhabiting the pyrolysis of hybrid reinforced fibers, woven roving (0°- 45°) carbon and kevlar (50/50 wt/wt), and an araldite resin composites were studied. The composites were synthesised and coated primarily by zinc borate (2ZnO.3B2O3.3.5H2O) and modified by antimony trioxide (Sb2O3) with different amounts (10-30 wt%) of flame retardant materials. In the experiments, the composite samples were exposed to a direct flame source generated by oxyacetylene flame (~3000oC) at variable exposure distances of 10-20 mm. The synergic flame retardants role of antimony trioxide and zinc borate on the composite surface noticeably improves the flame resistance of the composite which is attributed to forming a protective mass and heat barrier on the composite surface and increasing the melt viscosity.