EFFECTS OF FREEZE-THAW CYCLES ON THE MECHANICAL AND THERMOMECHANICAL PROPERTIES OF GFRP LAMINATES PRODUCED BY VACUUM INFUSION

This paper presents an ongoing study about the effects of freeze-thaw cycles (FTC) on the thermomechanical and mechanical properties of GFRP composite laminates produced by vacuum infusion using two different resins, unsaturated polyester (UP) and vinyl ester (VE). So far, the laminates were subjected to 100 and 200 FTC, from -20 ºC to 23 ºC. After each ageing period, the degradation was assessed by dynamic mechanical analysis (DMA) and different mechanical tests (tension, compression, flexure, in-plane shear and interlaminar shear). The results obtained so far indicate (i) slight-to-moderate reduction of the glass transition temperature, (ii) and also a decrease of the mechanical properties, especially in the flexural strength (up to 29%) and the compressive strength (up to 12%), which was partially reversible upon drying; and (iii) better overall performance of the VE composite.