TOF SIMS AND XPS STUDY OF THE INTERACTION OF AMINOSILANISED E-GLASS FIBERS WITH EPOXY-RESINS .1. DIGLYCIDYL ETHER OF BISPHENOL-S

The interaction between hydrolysed gamma-aminopropyltriethoxysilane (H APS) and the epoxy resin, diglycidyl ether of bisphenol S (DGEBS), wit h E-glass fibres has been studied by means of time-of-flight secondary ion mass spectrometry (TOF SIMS) and X-ray photoelectron spectroscopy (XPS). The contamination of the as-received, apparently non-silanised or non-coupled, E-glass fibre surface by a patchy monomolecular layer of HAPS has been demonstrated. Its influence on the chemisorption of an epoxy resin on to the fibre surface was also studied. After treatme nt of the non-coupled fibres with a fresh aqueous HAPS solution, the f ormation of a multilayer of HAPS on the fibre surface with the amino g roups at the outer surface and in a non-ionised form available for cou pling with the epoxy groups of DGEBS was apparent. On the DGEBS coated HAPS-coupled fibre surface, the formation of a coupling reaction prod uct between the amino groups of the HAPS deposit with the epoxy groups in the DGEBS deposit during the treatment has been demonstrated. Beca use of the presence of the HAPS contaminates, a similar result was als o obtained from the DGEBS coated non-coupled fibre surface. This provi des direct evidence for the interfacial microchemistry which explains the adhesion of the non-coupled fibres to an epoxy resin matrix implic it in a similar interfacial shear strength to that of the HAPS-coupled ones (Comp. Sci. Technol., 48 (1993) 89-96).