Studies of vapour-phase chemical derivatisation for XPS analysis using model polymers

Vapour-phase chemical derivatisation carried out on a vacuum adsorption rig has been investigated. Model polymers were used to evaluate the reactivity and selectivity of trifluoroacetic anhydride (TFAA) and hydrazine. Results have shown that TFAA is a good derivatising reagent for hydroxyl groups, while hydrazine is not suitable for carbonyl groups. Chemical derivatisation with TFAA of flame-treated polypropylene surfaces has shown that under various flame conditions an aoproximately constant proportion (ca. 20%) of the oxygen introduced by flame treatment was present as hydroxyl groups. Selective removal of OH groups by derivatisation has a large effect on the adhesion of a flame-treated polypropylene surface to a reactive polyurethane paint, evidence of chemical reaction at the interface.