Modification of montmorillonite and its effect on the thermal stability of PP/APP

Abstract

The effect of montmorillonite (Mt) and the treated montmorillonite (MtT) with sulfuric acid on the efficiency of nanoparticles of ammonium polyphosphate (APP) has been studied. Five samples containing different percentage of montmorillonite are prepared and other five samples containing treated montmorillonite also prepared. The chemical analysis (XRF), the spectroscopic measurements (XRD and IR) and the morphology (SEM) studied have been performed to identify the sulfuric acid treatment for the montmorillonite on the chemical composition and on the structure of the montmorillonite layers. The results have been revealed that the acid treatment changes the layered structure of montmorillonite and no effects on the chemical composition. The thermogravimetric analysis (TGA) is used to evaluate the ammonium polyphosphate (APP)/ montmorillonite (Mt) or APP/ montmorillonite treatment (MtT) as flame retardants for Polypropylene (PP). The results show that both treated and untreated montmorillonite when mixed with APP accelerate the first step of the thermal degradation. Also, it is indicated that the time of degradation increased by adding treated or untreated montmorillonite to APP in the following sequence PP<PP/APP<PP/(APP/Mt)<PP/(APP/MtT). Overall, the results indicated that the modification of added montmorillonite to App improves the flammability of the PP.