19F n.m.r. end-group analysis of a poly(aryl ether ether ketone) (PEEK)

19F n.m.r. spectroscopy of poly(ether ether ketone) (PEEK) and related model compounds has been performed in various solvents including sulphuric acid. Different chemical shifts have been observed on sulphonated samples and long range shielding effects are discussed. An alternative method for the M̄n evaluation of PEEK is proposed.