Thermoplastic‐thermosetting hybrid polymer systems as gap‐filling adhesives

摘要

AbstractThe most important requirement for a hot melt adhesive to perform well in gap‐filling applications is the ability to yield or flow under shrinkage tension which develops in the adhesives during cooling, while maintaining a satisfactory bond to the substrate. In addition, such an adhesive must have a high room temperature viscosity and high green strength to effect an acceptable bond before curing. We found that the required combination of properties for the gap‐filling applications can be achieved with interpenetrating networks of selected thermoset‐thermoplastic polymers. The best results were obtained with systems consisting of an amorphous polyester and an epoxy blend. The properties of these adhesives depend on numerous variables. This study concerns the three composition variables which appeared particularly important in the performance of these adhesives: (1) epoxy‐polyester ratio, (2) molecular weight of the epoxy system, and (3) the quality of dis