Effect of silane coupling agent adsorbate structure on adhesion performance with a polymeric matrix

The effect of the silane coupling agent adsorbate structure on adhesion performance is investigated. Glass beads are treated with two different sets of silanes where each set contains the same organo-functional group, but a different number of alkoxy groups, viz. one, two, or three. Adhesion strength measurements were obtained from tests in which single, silane-treated glass beads were imbedded into rectangular poly (vinyl butyral) specimens that were then subjected to an applied tensile stress until failure occurred at one of the poles of the sphere. The results indicate that the mono-alkoxy silanes have the least effect on adhesion, the consequence of poor attachment of the silane to the mineral surface, while the di- and tri-alkoxy silanes produce a marked increase in adhesion strength due to the increased stability of their bonds to the glass surface and their ability to form more extensive interphases with the polymer. (C) 2003 Elsevier Science Ltd. All rights reserved.