introductionAromatic poly(ether ketone) such as PEEK (3), has gained considerable importance due to its chemical resistance and excellent mechanical and thermal properties. Rose et al. ') were first to succeed in preparing high-molecular-weight 3, 4,4'-biphenyldiolbased poly(ary1 ether ketone), 4, and related semicrystalline polymers by choosing diphenyl sulfone as the reaction medium at a reaction temperature above 300°C.McGrath et al. *), and later Risse and Sogah3), reported the synthesis of an amorphous high-molecular-weight prepolymer containing removable tert-butyl substituents on the polymer chain. The bulky group could be cleaved to produce semicrystalline poly(ary1 ether ketone)s. Homogeneous hydrolysis of poly(ary1 ether ketimine) with trifluoromethanesulfonic acid was also reported by McGrath et al. ' ). The melting temperature, T,, of the resulting semicrystalline polymer was significantly lower than that of PEEK. The present paper describes a different approach to the hydrolysis of amorphous poly(ary1 ether ketimine)s 1 and 2. The required ketimine-to-ketone transformation was carried out under controlled heterogeneous hydrolysis conditions to afford semicrystalline poly(ary1 ether ketone)s. The polymers were characterized by differential scanning calorimetry (DSC) and the results were compared with the reported thermal transitions of PEEK and 4,4'-biphenyldioLbased poly(ary1 ether ketone) 4. Results and discussionSynthesis of poly(aryI ether ketirnine)s Polymerization of hydroquinone with appropriate ketimine functional difluoride was carried out in presence of potassium carbonate (excess) in N-methyl-2-pyrrolidone/ 0 1991, Hiithig & Wepf Verlag, Basel CCC 0173-2803/91/$01 .OO
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.