Aromatic polyetherketone

J. B. Rose and P. A. Staniland. Thermoplastic aromatic polyetherketones. US Patent 4 320 224, assigned to Imperial Chemical Industries Limited (London, GB2), March 16, 1982. 

During last years chemist-synthesists and technologists were interested in aromatic polyetherketones (PEK) and polyetheretherketones (PEEK). The main feature in the composition of aromatic thermoplastic polyethers - polyetherketones and polyetheretherketones is the presenee of one ether and one ketone group and two simple and one ketone group in their elementary bonds [1-3] ... 

Also, we have to notice, that the represented oligoketones in the capaeity of additive to high-density polyethilene can be used as fbrpolymers for the synthesis of high-molecular compounds of aromatic polyetherketones class which are very perspective materials of constmction purpose with higher physics and chemical characteistics. 

The first preparation of completely aromatic polyetherketones was reported by Bonner of du Pont [1], who obtained polymers of low molecular weight (Inherent. Viscosity, IV, 0.13-0.18) by the polyaroylation reactions (3) using both Isophthaloyl and terephthaloyl chlorides as monomers with... 

John B. Rose and Philip A Staniland. Thermoplastic aromatic polyetherketones. US Patent 4320224. March 12,1982. 

Polyetherketones and polyethersulfones, also referred to as polyketones and polysulfones, are synthesized by nucleophilic aromatic substitution between aromatic dihalides and bispheno-late salts [Cassidy, 1980 Clagett, 1986 Critchley et al., 1983 Harris and Johnson, 1989 Jayakannan and Ramakrishnan, 2001 Matsumura et al., 2001 May, 1988], This is shown in Eq. 2-206, where X is halogen and Y is C=0 or S02 ... 

Polyetherimides (PEI) are polyimides containing sufficient ether as well as other flexibi-lizing structural units to impart melt processability by conventional techniques, such as injection molding and extrusion. The commercially available PEI (trade name Ultem) is the polymer synthesized by nucleophilic aromatic substitution between 1,3-bis(4-nitrophthalimido) benzene and the disodium salt of bisphenol A (Eq. 2-209) [Clagett, 1986]. This is the same reaction as that used to synthesize polyethersulfones and polyetherketones (Eq. 2-206) except that nitrite ion is displaced instead of halide. Polymerization is carried out at 80-130°C in a polar solvent (NMP, DMAC). It is also possible to synthesize the same polymer by using the diamine-dianhydride reaction. Everything being equal (cost and availability of pure reactants), the nucleophilic substitution reaction is probably the preferred route due to the more moderate reaction conditions. 

Polymers such as polyetherketones and polyethersulfones can be prepared by electrophilic aromatic substitution using aromatic acid chlorides and aromatic sulfonyl chlorides, respectively [Eq. (25)]. However, due to ortho-substitution in addition to the desired para-substitution, it is difficult for these Friedel-Crafts acylations to compete with nucleophilic aromatic substitution of activated aromatic halides which are usually used for their synthesis. 

Several different approaches to the construction of poly(arylene-carborane)s were initially considered (Scheme 1). These included (i) nucleophilic polycondensation between a bis-phenol and an activated, carborane-based dihalide in the presence of base, a reaction used for the synthesis of commercial polyetherketones and polyethersulfones,4 (ii) electrophilic polycondensation between an aromatic diacid and a carborane-based diarylether in the presence of a strong-acid catalyst,5 and (iii) direct, homogeneously-catalysed coupling of a carborane-based dihalide.6 However,... 

A considerable amount of research has been carried out in recent years into the design of matrix materials for the next generation of supersonic civil transports and much of it has focused on amide, imide and related structures. Among resins studied are the polystyrylpyridine (PSP) family, the polyamide-imides, polyetherimides, polyetherketones, and for very high temperatures, the polyphenylquinoxalines, the polybenzimidazoles and the aromatic polyesters [50,51]. Some generalizations emerge [52] ... 

Compared to Nafion , a stronger confinement of water in the narrow channels of the sulfonated aromatic polymers leads to a significantly lower dielectric constant of the waters of hydration (20 compared to 64 in fully hydrated Nafion [185,186]). Of particular relevance to macroscopic models are the diffusion coefficients of water. As the amount of water sorbed by the membrane increases and molecular-scale effects are reduced, the properties approach those of bulk water on the molecular scale. Figme 26 shows the trend in proton mobility. Da, and water self-diffusion, Dh20. for Nafion and the sulfonated polyetherketone membrane [134]. 

Kadel Polyetherketone, aromatic, PEAK Amoco Performance Products... 

In fact all these properties were unavailable in conventional materials but may be covered by aromatic and heterocyclic Unear and thermosetting resins such as acetylene terminated resins, bismaleimides, polyetherimides, polyamide-imides, polybenzimidazoles, pol3dmides, polyetherketones, pol3qjhenylquinoxalines, polyphenylensulfides, polysulfones derivatives, polyst5nylp3nidines, fluoropol3mers, silicones, etc. 

Polyetherketone (PEK) is a partially crystalline high-performance aromatic ketone-based thermoplastic that is heat stable and readily processed. As a member of the ketone family it shares with PEEK such properties as good chemical resistance exceptional toughness. 

Polyetherketoneketone n A polyetherketone which contains two ketone links between benzene rings to each link. It has the highest glass transition and melting temperatures of all the commercial aromatic polyether ketones. 

These polymers have high glass-transition temperatures while their solubility in usual organic solvents enabling chemical modifications, is an indisputable asset. Moreover, as contrary to other aromatic polymers such as polyetherketone, polyether ether ketone, the polysulfone are fully amorphous their mechanical strength does not depend on crystallinity ratios and melting temperatures which are very sensitive to the nature of chemical modifications and to their extent. 

---