CHEMICAL RECYCLING OF FIBERGLASS REINFORCED THERMO-SETTING PLASTICS USING SUPERCRITICAL ETHANOL IN THE PRESENCE OF NaOH

Abstract

In recent decades, the issues of recycling polymer composite materials, especially fiberglass, have gained increasing relevance due to the growing amount of waste and the environmental resistance of these materials. Thermosetting resin-based composites are among the most challenging to recycle because of their high thermal resistance and chemical stability. This study examines the recycling process of fiberglass composites with epoxy and epoxy vinyl ester matrices using solvolysis in a supercritical ethanol environment in the presence of NaOH. Using thermal analysis methods, the dependence of the matrix degradation degree on the time and concentration of caustic soda was established. The optimal conditions for the degradation of epoxy and epoxy vinyl ester matrices were found to be an NaOH concentration of 0,3 g per 1 g of composite, at a temperature of 250 °C, with a processing time of 5 hours. Thermal analysis indicated that the epoxy vinyl ester matrix is more resistant to degradation under the studied conditions. The recovered glass fillers were used to produce short fiber-reinforced composites, with reinforcement content varying from 5 % to 60 %. The best mechanical properties were achieved in composites containing 30 wt. % of the recovered glass fillers.