The development of glass fiber reinforced polystyrene for pultrusion. I: Process feasibility,dynamic mechanical properties,and postformability

A feasibility study on the pultrusion of a glass fiber reinforced polystyrene (PS) has been conducted using a proprietary method. The styrene prepolymer synthesized in this study was prepared from blends of styrene monomer and benzoyl peroxide (BPO). The process feasibility, dynamic mechanical properties, and postformability of the glass fiber reinforced PS by pultrusion have been investigated. By means of gel permeation chromatography, ¹H nuclear magnetic resonance (¹H-NMR), and a Brookfield viscometer, the molecular weight, conversion, and viscosity of the styrene prepolymer were obtained. From the investigations of the long pot life of styrene prepolymer, the high reactivity of styrene prepolymer, and excellent fiber wet-out, it was found that the PS resin showed excellent process feasibility for pultrusion. The dynamic storage modulus (E') of pultruded glass fiber reinforced PS composites increased with increasing die temperature, filler content, postcuring and glass fiber content, and with decreasing pulling rate. The composite can be postformed by thermoforming under pressure, and mechanical properties of postformed composites can be improved.