Polyarylether ketone

Once again there are problems due to crystallisation as the polymer is being formed. One way of avoiding this, with the consequent throwing out of the growing polymer from the reactant mixture, is to react in a high boiling solvent at a temperature close to the of the polymer. 

Several poly aryl 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  

The polyaryl ether ketones quickly became established as outstanding heat- 

Excellent toughness and wear resistance. For example, the resistance to cut through of wire coverings is far superior to that of most other heat-resisting plastics. It is interesting to note that in 1994, 50% of applications of PEEK were related to the excellent wear behaviour. 

Excellent hydrolytic stability. (For example, PEK has very good resistance to hot water at 125°C, under which conditions other heat-resisting plastics such as the polyimides are liable to fail.) 

The main differences between the commercial types of PAEK arise largely from the differences in the r . Whilst the higher may lead to a higher heat deformation temperature, there is also a corresponding higher processing temperature required and this can have an adverse effect on the therm stability. Some typical properties are given in Table 21.6 but it should be pointed out that the data have been acquired from different sources and are therefore not closely comparable. 

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 

---

Polyarylether Ketones. The aromatic polyether ketones are tme thermoplastics. Although several are commercially available, two resins in particular, poly ether ether ketone [31694-16-3] (PEEK) from ICI and poly ether ketone ketone (PEKK) from Du Pont, have received most of the attention. PEEK was first synthesized in 1981 (20) and has been well studied it is the subject of numerous papers because of its potential use in high performance aircraft. Tough, semicrystalline PEEK is prepared by the condensation of bis(4-fiuorophenyl) ketone with the potassium salt of bis(4-hydroxyphenyl) ketone in a diaryl sulfone solvent, such as diphenyl sulfone. The choice of solvent is critical other solvents, such as Hquid HE, promote the reaction but lead to premature low molecular-weight crystals, which do not exhibit sufficient toughness (21). 

Nylon, polyacetal, polycarbonates, poly(2,6-dimethyl)phenylene oxide (PPO), polyimides, polyphenylene sulfide (PPS), polyphenylene sulfones, polyaryl sulfones, polyalkylene phthalates, and polyarylether ketones (PEEK) are stiff high-melting polymers which are classified as engineering plastics. The formulas for the repeating units of some of these engineering plastics are shown in Figure 1.15. 

Industrially this is often called a polyctherether ketone to emphasize the ether character hence the abbreviation PEEK. In actuality it is a polyarylether ketone. 

Stiff polymers, such as polyphenylene, nylon 66, polyphenylene sulfone, and polyarylether ketone (PEEK), have relatively high Tg values because of the presence of phenylene and sulfone or carbonyl stiffening groups in the chain. 

Aromatic polymers such as PS are readily attacked by chlorine bromine, concentrated sulfuric acid, and nitric acid. These reactions do not decrease the degree of polymerization of the polymers. Aromatic polymers with stiffening groups, such as PPO, polyarylsulfone, polyarylether ketone (PEEK), and polyphenylene sulfide (PPS), are more resistant to attack by corrosives than those with flexibilizing groups. 

Polyarylether ketone (PEEK) has the following repeating unit ... 

Features of the new, inherent, flame-resistant active polymers such as PSU (polysulfone), PES (polyether sulfone), and PAEK (polyarylether ketone) include high levels of temperature resistance and very low smoke gas densities. 

Polyarylene ether ketone. See Polyether ketone Polyarylether ketone resin CAS 55088-54-5 60015-05-6 Synonyms PAEK PEKEKK Poly (1,4-benzenedicarbonyl-alt-bis (4-phenoxyphenyl) methanone) Poly ether ketone ether ketone ketone Poly (oxy-1,4-phenylenecarbonyl-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylenecarbonyl-1,4-phenylene) resin Classification Polymer... 

Poly ether ketone ether ketone ketone. See Polyarylether ketone resin... 

Ultranox 254. See 2,2,4-Tri methyl-1,2-dihydroquinoline polymer Ultranox 257. See p-Cresol/dicyclopentadiene butylated reaction product Ultranox 276. See Octadecyl 3,5-di-t-butyl-4-hydroxyhydrocinnamate Ultranox 641. See 2,4,6-Tri-t-butylphenyl 2-butyl-2-ethyl-1,3-propanediol phosphite Ultrapaque PCC. See Calcium monocarbonate Ultrapek KR 4176, Ultrapek KR 4177, Ultrapek KR 4178. See Polyarylether ketone resin... 

Polyarylate resin Polyarylether ketone resin Polyester carbonate resin Polyetherimide resin Polyethylene, chlorinated Polyethylene glycol Polyethylene, medium density Poly (p-methylstyrene) Poly (p-methylstyrene), rubber-modified Poly (oxy-1,2-ethanediyloxycarbonyl-2,6-naphthalenediylcarbonyl) resin Poly (oxy-p-phenylenesulfonyl-p-phenyleneoxy-p-phenyleneisopropylidene-p-phenylene) resin Poly (phenyleneterephthalamide) resin Polysulfone resin Poly (tetramethylene terephthalate) Polyvinylidene chloride Potassium sorbate Potato (Solanum tuberosum) starch Silica, colloidal Silicone Sodium N-alkylbenzenesulfonate Sodium bicarbonate Sodium tetraborate pentahydrate Starch, pregelatinized Styrene/acrylates copolymer Styrene/butadiene polymer Styrene/DVB copolymer , 1,1 -Sulfonylbis (4-chlorobenzene) polymer with 4,4 -(1-methylethylidene) bis (phenol) and 4,4 -sulfonylbis (phenol) Synthetic wax Tapioca starch Tetrafluoroethylene/perfluoro (propyl vinyl ether) copolymer Tocopherol Triglycidyl isocyanurate VA/crotonates copolymer Vinyl chloride/ethylene copolymer Wheat (Triticum vulgare) starch... 

Crotonic acid 2-Ethylhexyl chloride 2-Methylpropanal Pyrocatechol Triisobutylene resin synthesis, coatings m-Divinyl benzene resin, automotive components Polyarylether ketone resin resin, blow moldings Ethylene/methyl acrylate copolymer Polyarylether ketone resin resin, coatings Epoxy-novolac resin, coatings UV-curable... 

Ethylene/methyl acrylate copolymer resin, film extrusions Polyarylether ketone resin resin, food-contact coatings Epoxy-novolac... 

Polyarylether ketone resin 60018-94-2 Permethrin 60047-17-8 Linalool oxide 60063-90-3... 

A study by Yuan and co-workers [26] discusses the influence of molecular weight on the thermal and rheological behaviour of polyarylether ketone. Melt temperature, crystallisation phenomena and rheological properties were compared for polymers with different molecular weights. 

---