TRIFLUOROETHANOL DERIVATIZATION OF CARBOXYLIC ACID-CONTAINING POLYMERS FOR QUANTITATIVE XPS ANALYSIS

The carboxylic acid groups of poly(acrylic acid) (PAA) and poly(methac rylic acid) (PMAA) were derivatized in the solid state using a procedu re resulting in esterification by trifluoroethanol vapour. X-ray photo electron spectroscopy analyses indicate that stoichiometric reaction w ith PAA was reached after 10 h. However, PMAA did not attain a yield g reater than 60%, an effect rationalized in terms of steric hindrance. It is postulated that steric restraints are imposed by conformational inflexibility related to the pendant methyl group within isotactic por tions of the chain.