In situ pultrusion of vinyl ester/nano-mica matrix composites: Process feasibility and process parameters

We conducted a feasibility study on the pultrusion of glass fiber-reinforced vinyl ester/nano-mica matrix composites through a proprietary in situ method. The matrix prepolymer for pultrusion is to be prepared by blends of vinyl ester, initiator (t-butyl perbenzoate), and nano-mica. It is desired to investigate the process feasibility and parameters of the unidirectional glass fiber-reinforced vinyl ester/nano-mica matrix composites through in situ pultrusion. The characteristics of long pot life, high reactivity, and excellent glass fiber wet out of the vinyl ester/nano-mica matrix confirmed its excellent process feasibility for in situ pultrusion. The effects of the optimal process parameters, including die temperature, pulling rate, postcure temperature and time, filler (nano-mica) content, and glass fiber content, were investigated. The optimal die temperature was determined on the basis of a differential scanning calorimetry diagram and conversion of the vinyl ester/nano-mica matrix. The mechanical properties of pultruded composites decreased with increasing pulling rate and increased at a suitable postcure temperature and time. Furthermore, the properties decreased because of the degradation of pultruded composites for a long postcure time. The mechanical properties of pultruded composites achieved maximum values at 2 phr and 75.6 vol% corresponding to nano-mica and glass fiber content and then decreased.