Poly(ether ketone)s by Fluoride Catalyst Systems

Abstract

Potassium fluoride or a mixture of potassium fluoride and iV-neopentyl-4-(dialkylamino)pyridinium chlorides 7,8, or 9 were used as catalysts to improve poly(ether ketone) syntheses of dichloroaryl monomers such as l,4-bis(4-chlorobenzoyl)benzene (1) via nucleophilic displacement. Polymers of increased molecular weight within a significantly reduced reaction time can be obtained by this method, as demonstrated with condensations of 2,2-bis(4-hydroxyphenyl)pentane (4) or 2,2-bis(4-hydroxyphenyl)heptane ( 5) with 1. Furthermore, high molecular weight semicrystalline poly(ether ether ketone)s, commonly known as PEEKK, were synthesized by fluoride anion assisted polycondensation of 1. Under severe conditions, fluoride induced nucleophilic cleavage of the activated ether linkages of the polymers was found.

Highly Fluorinated Poly(arylene ether ketone) Prepared by a CaH2‐Mediated Polycondensation Reaction

“…This reaction represents a completely different mechanism to that associated with the chain degradation of non-fluorinated polyether ketones and sulfones, [14][15][16][17][18][19][20] where the center of the degradation is the ether group. Clearly in the case of the fluorinated polymers, the ketone groups are more sensitive to nucleophilic attack than ether groups.…”

“…The presence of trace amounts of water in association with fluoride ions produced during the reaction in the solution will cause serious polymer degradations by side reactions such as hydrolysis and chain scission. [17][18][19][20] It has been reported that the introduction of calcium or magnesium carbonates into the reaction associated with an alkali metal carbonate facilitates the polycondensation. [21][22][23][24][25] Very high molecular weight poly(arylene ether)s have been synthesized when a mixture of calcium carbonate and a small amount of potassium carbonate is used, whereas only low molecular weight polymers are produced using potassium carbonate alone.…”

“…This is extremely advantageous since the presence of F À in the reaction solution can attack the polymer and degrade the polymer chain in addition to hydrolysis and cyclization reactions. [14][15][16][17][18][19][20] …”

Cesium fluoride-mediated synthesis of aromatic polysulfides from aromatic dithiols and activated aromatic dihalides

“…It was reported that activated ether linkages could be cleaved by fluoride ion 10,11) . By analogy, it is reasonable that CsF used for the polymerization, coupled with higher reaction temperature (160 8C), cleaved sulfide linkages and resulted in molecular weight decrease of the aromatic polysulfides.…”

Properties of a few aromatic poly(thioether ketones) as sulfur‐containing high‐performance polymers

“…[1][2][3][4] Further, PEEK is a very expensive polymer because highly electrophilic but costly 4,4Ј-difluorobenzophenone is necessary as a monomer to obtain high molecular weight PEEK. 1,5,6 In an attempt to overcome these drawbacks, various poly(ether ketones) (PEKs) have been developed, and their properties in relation to their chemical structures have been extensively studied. [2][3][4][5][7][8][9][10][11] We previously prepared PEK-1 with both high T g (228°C) and good solubility resulting from the use of a 2,6-dimethyl-1,5-bis(benzoyl)naphthalene unit in the polymer.…”