Curative-Silane Interactions for Low Temperature Curing Adhesives

As pushes for lower carbon footprint processes emerge, OEMs have been shifting to lower oven temperatures to reduce the amount of energy they use. The adhesives used within the automobile parts must properly cure at these lower temperatures and continue to meet specifications, which requires some reformulation to better the adhesive. One such additive that can help with lower temperature curing is silanes. As a preliminary trial, a methacrylate-functional silane adhesion promoter was used to improve adhesion at lower temperatures. Two different curatives used were an acrylate-based curative and a methacrylate-based curative. Due to the extra methyl group, the methacrylate-based curative has slower kinetics than the acrylate-based curative; however, with conjunction of the methacrylate-functional silane adhesion promoter, some unexpected changes to adhesion performance were observed. This study was to investigate the curing mechanisms by which the acrylate- and methacrylate-based curatives affect adhesion in the presence of a methacrylate-functional silane adhesion promoter.