TOF-SIMS AND XPS STUDIES OF THE INTERACTION OF SILANES AND MATRIX RESINS WITH GLASS SURFACES

The interface between glass, glass fibres and epoxy resin in a composi te has been studied using time-of-flight secondary ion mass spectromet ry in static and scanning modes in combination with x-ray photoelectro n spectroscopy. The presence of a multilayer of the polymeric hydrolys ed gamma-aminopropyltriethoxysilane (HAPS) on the glass surfaces has b een confirmed. After extraction with bot water or toluene only a monom olecular interfacial layer of HAPS is chemically bound to the immediat e glass surface through siloxane bonds, leaving the amino groups at th e outer surface and available for reaction. It has been demonstrated t hat this interfacial layer plays an essential role in the coupling rea ction between the amino group of the HAPS deposit and the epoxide grou p of the epoxy resins, diglycidyl ether of bisphenol A or S (DGEBA or DGEBS). These interfacial reactions were complicated by the presence o f polydimethylsiloxane and the incorporation of substrate aluminium in to the HAPS deposit. The aluminium sites appeared not to be involved i n the coupling reaction.