SURFACE MODIFICATIONS OF POLY(ETHER ETHER KETONE)

Reactions of semicrystalline poly(ether ether ketone) (PEEK) film with carbonyl-selective reagents at the film-solution interface produce modified film samples containing a thin surface layer of the reagent-induced functionality. Semicrystalline PEEK film is robust and unaffected by a variety of solvent and temperature conditions, allowing a range of standard ketone derivatizations to be carried out. In contrast, amorphous PEEK film is swollen and physically deformed by solvents that do not affect crystalline PEEK. Crystalline PEEK reacts with 2,4-dinitrophenylhydrazine to yield PEEK approximately C=NNHPh(NO2)2 and with hydroxylamine to PEEK approximately C=NOH. Reaction with methylenetriphenylphosphorane gives PEEK approximately C=CH2. Dimsylsodium adds to the PEEK carbonyl, rendering PEEK approximately C(OH)CH2S(O)CH3. Sodium bis(2-methoxyethoxy)aluminum hydride reduces the PEEK carbonyl (PEEK approximately CHOH). Cyanosilylation of PEEK with trimethylsilyl cyanide yields PEEK approximately C(CN)OSiMe3. PEEK approximately CHOH and PEEK approximately C=NOH react with benzenesulfonyl isocyanate to yield PEEK approximately CHOC(O)NHSO2Ph and PEEK approximately C=C(O)NHSO2Ph, respectively. PEEK approximately CH=CH2 reacts with bromine to form PEEK approximately CHBrCH2Br; reaction of PEEK approximately CHOH with thionyl chloride yields PEEK approximately CHCl. Reactions were monitored and products were characterized by contact angle, XPS, and ATR IR. Yields were assessed by quantitative XPS analysis of the outer 40 angstrom and were generally approximately 50% for reactions with PEEK. One non-carbonyl-selective reaction, oxidation with potassium chlorate/sulfuric acid is also reported.