ABSTRACT
A flame retardant composite similar to a commercial flame retardant masterbatch was aimed to be developed in this study. The commercial masterbatch was characterized by its functional groups, the elemental composition, crystal structure, morphology, and thermal stability, and limiting oxygen index (LOI). It was a polypropylene matrix composite filled with a clay mineral most probably montmorrilonite and a phosphate compound. Thus vermiculite which is a clay mineral and a phosphate compound and zinc phosphate were added to polypropylene matrix in order to improve flame retardancy. Fillers were coated with stearic acid to make them compatible with polypropylene. It was observed that the composites having 20% zinc phosphate had the highest degradation onset temperature (261°C). The remaining mass at 600°C was 21% for commercial masterbatch, 22% for 20% zinc phosphate, 33% for 10% zinc 60phosphate, and 10% vermiculite and 43% for 20% vermiculite composite. The additives in the composites had no significant effect on the activation energy of polypropylene degradation, but they led the formation of more solid carbonized compounds. It was understood that 20% vermiculite composite had the highest smoke suppression capacity and formed less gaseous and more solid degradation products. The LOI was 22% for flame retardant masterbatch, 19% for polypropylene and composites having vermiculite and 18% for zinc phosphate. In conclusion the composites prepared were not as succesful as commercial masterbatch in flame retardancy, however, the composite with 20% vermiculite had higher smoke suppression capability and the composite with 20% zinc phosphate had highest degradation onset temperature (261°C).
