Thermal characterization of the interaction of a silane adhesive and dihydroxy vulcanized fluoroelastomers

The importance of this paper verifies that the interaction of adhesive to a dihydroxy rubber compound, for cure interactions, can successfully be monitored. The activity of an Aminosilane and Vinylsilane with a dihydroxy (Bisphenol AF) crosslinkable fluoroelastomer containing only Vinylidene Fluoride (VF2) and Hexafluoropropylene (HFP) was monitored using various techniques. The techniques used were the Differential Scanning Calorimeter (DSC) and X-Ray Photoelectron Spectroscopy (XPS). The results of the DSC showed that the introduction of an Aminosilane, or combination of the Aminosilane and Vinylsilane adhesive solutions to the cure system of the fluoroelastomer resulted in a shift in the exothermic cure peak. This shift indicates a change in the cure characteristic of the fluoroelastomer. (i.e. The onset cure temperature as well as the maximum cure temperature is lowered). Results also confirm that the organofunctional group on the silane reacts with the rubber. XPS analysis of the silane coated fluoroelastomer heated at 120°C, 160°C and 200°C, reveals that dehydrofluorination occurs from the interaction. It is our hypotheses that the amine group on the aminosilane could be a contributor to the dehydrofluorination of the fluoroelastomer.