Reactive and non‐reactive binders in glass/vinyl ester composites

Abstract This study characterizes and evaluates two types of preform binders: reactive thermosets, and non‐reactive thermoplastics. The interply adhesion between woven glass plies was measured as a function of binder type, concentration, and preforming conditions. It was found that reactive binders offer the potential to provide much larger interply adhesions between glass plies in a preform than thermoplastics, and are thus superior choices for the fabrication of complex‐shaped preforms requiring little or no springback. Laminated composite panels fabricated from preforms with varying binder concentrations were evaluated in regards to their interlaminar properties. It was found that both binder types degraded the interlaminar shear strength of a woven glass reinforced vinylester composite. Additionally, composite laminates made from preforms containing the thermoplastic binder showed decreases in the interlaminar fracture toughness of the composite by approximately 60%. However, composite laminates fabricated from preforms utilizing the reactive epoxy binder showed an increase in fracture toughness of approximately 47%. Hence, it is concluded that a range of interlaminar properties can be achieved depending on the type of binder, the amount of binder, and the processing of the binder and also that of the composite itself. POLYM. COMPOS., 26:377–387, 2005. © 2005 Society of Plastics Engineers