The development of glass fiber reinforced polystyrene for pultrusion. II: Effect of processing parameters for optimizing the process

This paper presents a novel process developed to manufacture polystyrene (PS) pultruded composites. The effects of the processing parameters on the mechanical properties (tensile strength, flexural strength, flexural modulus, etc.) of the glass fiber reinforced PS composites by pultrusion have been studied. The processing parameters investigated include die temperature, pulling rate tin-line speed), postcure temperature and time, filler type and content, and glass fiber content. The optimum die temperature was determined from DSC diagrams, molecular weight, and mechanical properties tests. It was found that the mechanical properties increased with increasing die temperature and glass fiber content, and with decreasing pulling rate. The optimum die temperature, pulling rate, and glass fiber content were determined to be 160-200 degrees C, 20-60 cm/min and 50-60 vol%, respectively. The mechanical properties reached a maximum value at 10 phr kaolin, and then decreased. However, the properties decreased with increasing talc content. The mechanical properties increase at a suitable postcure temperature and time. Furthermore, the properties that decreased as a result of composite degradation after long postcure time are discussed.