ANALYSIS BY PYROLYSIS-GAS CHROMATOGRAPHY MASS-SPECTROMETRY OF GLASS-FIBER VINYLESTER THERMAL-DEGRADATION PRODUCTS

The study of the thermal degradation of vinylester materials crosslinked with styrene by thermogravimetric analysis (TGA) and the identification of emission products by pyrolysis/chromatography/mass spectrometry (PY/GC/MS) demonstrates that thermal degradation begins with a polystyrene chain depolymerization. It continues with the breaking of vinylester prepolymer chains at higher temperatures Thermal degradation product analysis allowed us to confirm polystyrene formation during resin crosslinking. A post-cured material allowed us to obtain better thermal stability and to limit, for a given temperature, the fraction of volatile products. The use of a 45 instead of a 50% styrene resin allowed us to limit the degradation product yield. The presence of glass fiber in the vinylester matrix decreases the number of crosslinking points and the thermal degradation occurs more readily in the prepolymer chain end.