Interaction of silica with polystyrene: Mechanical properties, polymer/filler adhesion and failure behavior

Abstract

Composites of polystyrene with different loading of silica were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm. The mechanical properties of the composites such as tensile behavior, impact strength, and flexural properties were studied as a function of filler load-ing. The tensile moduli of the composites increased with silica content. To improve adhesion between the filler and the matrix, an amino silane cou-pling agent was used. The composites with coupling agents showed en-hanced mechanical properties. Thermal properties were measured using differential scanning calorimetry (DSC), thermogravimetry (TGA) and flammability tests. Composites with 15 wt.% and 0.5 wt.% coupling agent showed optimum properties. Scanning electron microscopy (SEM) studies of the tensile fractured samples revealed the extent of filler dispersion and filler/matrix interaction. Finally, experimental results were compared with theoretical predictions.