Influence of ceramic particle features on the thermal behavior of PPO-matrix composites

Thermoplastic poly(phenylene oxide) (PPO)-matrix composites were prepared and characterized in order to evaluate the effect of different ceramic fillers on the thermal and combustion behavior of the matrix. In particular, ceramic particles having three different shapes were exploited as fillers, particles showing a platelet-like, a needle-like or an equiaxial morphology. The composite materials were produced through a melt blending method, which yielded a homogeneous distribution of the ceramic particles in the organic matrix. It was demonstrated that the presence of the inorganic particles influenced the temperature range in which the degradation processes of the polymer occurred. In addition, the three fillers modified the thermal behavior of PPO differently in terms of enthalpy. Finally, the presence of the filler induced a change in combustion behavior of the polymeric matrix; in particular, sepiolite was able to increase the charring ability of the PPO/polystyrene blend with the development of a visible carbonaceous layer.