Utilizing hydrolyzed powder recyclates as filler in polystyrene

In the present study, hydrolyzed powder coating wastes were used as filler materials in polystyrene compounds, and the effect on the mechanical properties, melt flow index and density of polystyrene compounds were investigated. Epoxy/polyester, epoxy and polyurethane systems with thermoset structure were used as powder coating recyclates. After separately hydrolyzing these wastes, 5%, 10%, 20% and 30% by weight were homogeneously mixed with polystyrene, initially mechanically and subsequently with an extruder in the melt at 180 degrees C. The resulting compounds were cooled and granulated, and by use of an injection molding machine at 180 degrees C to 200 degrees C, standard tensile test bars were produced. Tensile strength, bending strength and izod impact strength of the test bars were measured and the variations of the mechanical properties of the polystyrene compounds as a function of the type and amount of filler were examined. In addition, melt flow index and density of the compounds were determined. Furthermore, the bonding mechanism of filler and matrix material was examined by electron microscopy.