Adhesive bonding of eastern hemlock glulam panels with E-glass/vinyl esterreinforcement

The development of novel hybrid fiber-reinforced polymer (FRP) wood composi tes requires the study of resin matrices not commonly associated with wood adhesive bonding. Vinyl ester resin systems are used extensively in the pro duction of FRP composite materials due to excellent chemical resistance and tensile strength combined with low viscosity and fast curing. An efficient composite panel for decking applications is proposed by reinforcing easter n hemlock glulam panels with E-glass/vinyl ester resin face sheets. In this study, we examined the adhesive shear strength of vinyl ester resin bonded wood, and compared this to phenol resorcinol formaldehyde (PRF) bonded woo d using a modified ASTM D 905 Compression Shear Test and a cyclic delaminat ion test. A hydroxymethylated resorcinol (HMR) primer was also examined as a means to improve vinyl ester bonding with wood. Shear specimens were test ed dry and tested wet after vacuum-pressure saturation. Cyclic delamination specimens were evaluated during five cycles of accelerated-aging exposure. Results indicated that vinyl ester resin with HMR primer can form strong a nd exterior-durable adhesive bonds with wood.