Resin hardness and interlaminar shear strength of a glass-fibre/vinylester composite cured with high intensity ultraviolet (UV) light

Experimental results on properties achieved for bulk vinylester resin and a glass-fibre/vinylester composite cured through exposure to high intensity UV light, was reported. An epoxy vinylester resin was formulated ratio by weight of phosphine oxide-based photoinitiator. The bulk resin was poured into a 10 mm diameter cylindrical mould to a depth of 8 mm. The mould was placed under a high-intensity UV spotlight. The diameter of the aperture at the tip of the guide was 1 mm and the distance from the tip to the surface of the resin was 20 mm. Rockwell hardness testing for polymers was conducted according to ASTM D 785-89. A composite laminate for interlaminar shear testing was made by hand lay-up unidirectional E-glass fibres. Test samples were cut from the laminate using a watercooled diamond saw. The shear strength result and the observed fracture behavior support a conclusion that a high degree of cure and mechanical performance can be attained with high intensity UV curing.