Polyaryl ether ketone

The polyaryl ether ketones quickly became established as outstanding heat-... 

Polyaryl ether ketones may be processed on conventional injection moulding and extrusion equipment, providing sufficiently high temperatures can be achieved. Melt temperatures required are typically 370°C for unreinforced PEEK, 390°C for reinforced PEEK and both unreinforced and reinforced PEK and unreinforced PEEKK, and 410°C for reinforced PEEKK. For the latter material a temperature profile from feed zone to nozzle would be... 

Various kinds of engineering thermoplastics such as polyether sulfone, polyether imide, polyaryl ether ketone, and polyphenylene oxide have been studied as toughening agents for... 

Polyaryl(ether-ketone-carbaborane)s have also been synthesized by using CF3SO3H as both solvent and catalyst to give linear amorphous polymers [Eq. (54)] [163]. These polymers have low molecular weights (IV = 0.24-0.59) and low thermolytic weight loss upon pyrolysis (10-15% at 1000° C)... 

Several polyaryl ether ketones, generically given the abbreviation PAEK, have been reported in the literature, including those shown in Table 21.5. Of these, three have been in commercial production. They are ... 

J. Koch, G. Schuermann, and G. Heinz. Stabilized polyaryl ether ketone molding compositions containing a phosphorus compound. US Patent 5 145894, September 8, 1992. 

Poly(ether ether ketone) (PEEK) was one of the first of the new generation of engineering thermoplastics introduced and developed by ICI in 1977 and was first marketed in 1978 (Chen and Porter 1994). PEEK is one of the highest-rated thermoplastic materials in terms of heat resistance. The material is one of the polyaryl ether ketone families, which are a group of partially crystalline polymers that are suitable for use at high temperatures. The useful properties of the material are retained at temperatures as high as 315°C. 

The convenience of size exclusion chromatography (SEC) as a means for the determination of the molecular mass distribution of a wide variety of synthetic polymers was appreciated early [1]. It was developed, however, for low-temperature application principally for reasons of safety and ease of use. Tetrahydrofuran, THF, had been adopted as a general-purpose mobile phase, and its low boiling point and the ease with which it formed peroxides restricted its use to temperatures below 40°C. This meant that many commercially important polymers, such as polyethylene, polypropylene, and polyaryl ether ketone could not be analysed, since they required high temperatures for dissolution. The high-boiling halogenated aromatics and substituted phenols were found to be suitable solvents for these polymers, and with increased temperature the scope for SEC was vastly increased. 

This polymer is used widely in engineering applications. Understanding its thermal and rheological behaviour is critical to predicting its moulding processability, post process properties and structural behaviour and properties. Such studies focus on the influence of molecular weight on thermal and rheological properties of polyaryl ether ketones. 

Yuan and co-workers [14] used DSC, dynamic mechanical thermal analysis and capillary rheometry to compare T, crystallinites, crystallisation temperature and rheological properties of polyaryl ether ketones with different molecular weights. 

Fig. 11.10 Water uptake isotherms of various ionomers and sulfuric acid at 80 C. Dowex 50 is an ion-exchange resin made of 4% cross-linked polystyrene divinyl benzene BPSH 40 is a 2-mil 40% randomly sulfonated biphenol sulfone 700 EW PFSA is a 1-mil membrane with a structure similar to Nafion Nafion 112 is a 2-mil extruded membrane and, PAEK triblock is a 1-mil triblock polyaryl ether ketone with a sulfonated middle block (Reproduced from C.K. Mittelsteadt and H. Liu. [30] by permission from John Wiley Sons)...

Raman spectra of polyaryl ether ether ketone and polyaryl ether ketones. 

High-temperature thermoplastics, such as polysulfone, polyether sulfone, polyphenylene sulfide, polyether imide, polyaryl ether ketone, and polyphenylene ether are processed at high temperatures (some above 300 °C). Here, the limit of pyrolysis is almost reached. Degradation and cross-linking as well as discoloration can occur thermal-oxidative and thermal-mechanical degradation under processing conditions have not been sufficiently investigated [38]. 

Polyaryl ether ketones are resistant to almost all organic and inorganic liquids at room temperature. The only exceptions are sulfuric acid and some strongly oxidizing media, such as fuming nitric acid. Even at elevated temperature, the chemical resistance of this class of products is superior to that of other high-temperature thermoplastics. Hairline cracks are formed in acetone [723]. 

Polybutylcyanoacrylates [63], polyacrylics [64], polybutadiene [65], flame retardant PE [66], PS [67-70], PS - divinyl benzene copolymer [71], PS - acrylonitrile copolymer [72], acrylonitrile-butadiene-styrene terpolymer [73, 74], styrene-maleic anhydride copolymer [75], polyvinyl-cyclohexane [76], polyphenylene triazine [77], poly-4-vinyl pyridine [78], polyethylene sulfide [79], PSF [80], brominated PES [81], tetrafluoroborate doped polythiophene [82], polysiloxane [56, 83], vinyl pyrrolidone-methacryloxy silicone copolymer [50], polyvinyl indene [84], poly-E-lactide [3, 85, 86], epoxy resins [87, 88], polyaryl ether ketone [89, 90], ethylene... 

Blends of BPADA-based Pis are also miscible with polyaryl ether ketones such as polyetherether-ketone (PEEK). As injection molded, many PEEK-PEI blends are transparent. 

Table 12.1 The Structures of Several Commercial Polyaryl Ether Ketone Polymers... 

A study was made of the miscibility in the amorphous region of melt mixed blends composed of a novel polyaryl ether ketone (PK99) and PEEK using various methods. 

Polyaryl ether ketone (PAEK) (PEEK, polyetheretherketoneketone (PEEKK), polyether ketone (PEK)) Liquid crystal polymer (LCP)... 

Polyaryl ether ketones are composed of aryl ether groups and aryl ketone groups. 

Aromatic polymers have many desirable properties such as good lap shear strength, thermal stabihty, and tensile strength, which make them useful for a wide variety of applications. The term aromatic polymer is used herein to mean a polymer, which has aromatic groups incorporated in the repeat unit of their backbone chain. Such polymers include polyimides (Pis), polyetherimides, polysulfones, polyether sulfones, polyaryl ether ketones, polycarbonates, poly-arylates, and the like [20]. 

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