ABSTRACT
This paper presents a study of the interaction of γ-aminopropyltriethoxy silane (APS) with an E-glass surface and subsequent dosing with a range of phenolic resins of differing chemistry (Novolaks and Resoles) and of differing molecular weight. High resolution XPS surface analysis showed that the APS deposit contained free and protonated amine components. It was confirmed that during aqueous treatment the extraction of non-silica substrate elements occurred with aluminium enrichment of the deposit. It is postulated that the protonated amine component may involve the presence of Al—OH in the deposit and penetration of the silane into the denuded glass surface.
On treatment with phenolic resins a quaternary ammonium ion forms which can be attributed to a reaction product of the phenolic resin with the amine group of the silane. Furthermore, a strong hydrogen bonded component was also observed which could be intermediate in this reaction. In addition, differing degrees of phenolic resin penetration into the ‘silane’ deposit was observed, which appeared to be related to the molecular weight of the resin.
Thus under the conditions employed the aminosilane can be involved in the chemical coupling of the phenolic resin to the glass surface. The micromechanics of adhesion to the glass fibres was examined by bimatrix fragmentation. This confirmed the chemical evidence that APS was an effective coupling agent for the range of phenolic resins.
