Polyether ether ketone structure

Polyether ether ketone (PEEK) (structure B of Table 21.5). This material was first prepared in the laboratories of ICI in 1977 and test marketed in 1978. The material is now marketed by Victrex as Victrex PEEK. 

High purity 4,4 -diphenoxy benzophenone is a key starting material for the production of high molecular weight polymers. Thus, its polycondensation with terephtaloyl chloride in presence of Friedel-Crafts catalyst gives polyether-ether ketones (PEEK) with the structure depicted on scheme 17 ... 

More recently, thermoplastics such as polyphenylene sulfide (PPS), polyether sulfone, and polyether ether ketone (PEEK) have entered the primary structures market in competition with thermosets. 

Thermoplastic matrices, is particularly attractive for automotive applications PP, for example, is economical, it can be processed quickly and can provide much better mechanical properties such as impact resistance, (i.e., bumpers, body panels [11]). PA are successfully applied in both under hood (i.e., inlet manifolds, radiator fans) and interiors (instrument panels, doors, front-end structures). For better temperature performance and mechanical properties, in some special application areas (motor racing sector, gearbox parts), polyether ether ketone and polyphenylene sulfide ( high performance thermoplastics ) are also used as matrices. 

In terms of polymer matrices for composite materials, there will be a compromise between solvent and water resistance. Thus non-polar resins are likely to be less resistant to hydrocarbon solvents, which have low polarity, but more resistant to moisture absorption. Polar resins behave in the opposite way. Strongly polar solvents, such as dimethyl sulphoxide or similar, can interact with polar structures in the resin and are difficult to resist. Crystalline thermoplastic polymers are often better for such applications. For example, polyethene will only dissolve in hydrocarbon solvents (of similar solubility parameter) at temperatures above the crystalline melting point. Polar semi-crystalline polymers such as the polyamides or nylons can be dissolved in highly polar solvents, such as cresol, because of a stronger interaction than that between molecules within the crystallites. High performance thermoplastic polymers such as polyether ether ketone (PEEK) have been promoted for their resistance to organic solvents (see Table 3.5) [12], The chemical resistance of unsaturated polyester and vinyl ester and urethane resins is indicated in Table 3.6 [15]. 

Intrinsically non-flammable polymers are few, but phenolic resins have a good reputation both in Are and smoke performance, which has resulted in their becoming increasingly favoured for reinforced plastics structures, for example, underground transport, where such concerns are greatest. Polyether ether ketone (PEEK) is also a low fire and smoke polymer. Unsaturated polyesters, vinyl esters and epoxy resins bum readily, but modified versions are available with improved behaviour. For example, both bromine and chlorine are used extensively in the form of chlorendic (HET) acid, tetrachlorophthalic anhydride (TCPA) and tetrabromo-phthalic anhydride (TBPA) which can be reacted into the polyester in small quantities and can act as permanent (non-migrating) flame retardants. 

Polyether ether ketone 30% mica and mica and glass fiber reinforced High-dimensional stability components, structural housir... 

Polyether ether ketone (PEEK) is a linear, aromatic, semi-crystalline thermoplastic possessing excellent thermal stability, chemical resistance and mechanical properties under engineering applications. It has the repeating unit structure, 0—Ph—O—Ph—CO Ph—, wherein "Ph" is the 1,4-phenylene unit. Its true scientific name is poly (oxy-1, 4-phenylene-oxy-l, 4-phenylenecarbonyl-l, 4-phenylene). The polymer is featured in a wide range of applications including transportation, energy, industrial, electronics, semiconductor and medical. 

Polyether ether ketones (PEEKs) are a polycondensation product of 4, 4 -difluorophenyl ketone, hydroquinone, and anhydrous sodium carbonate (or potassium carbonate). The molecular structure is as follows ... 

The family of aromatic polyether ketones includes structures that vary in the location and number of ketonic and ether linkages on their repeat unit and therefore include polyether ketone (PEK), polyether ether ketone (PEEK), polyether ether ketone ketone (PEEKK), as well as other combinations. Their structures are as shown in Fig. 1.39. AH have very high... 

Polyether ether ketone, hard plasticizer-firee polymer with the general structure (with x= 2, y=l) ... 

Over the past decade, literally dozens of new AB2-type monomers have been reported leading to an enormously diverse array of hyperbranched structures. Some general types include poly(phenylenes) obtained by Suzuki-coupling [54, 55], poly(phenylacetylenes prepared by Heck-reaction [58], polycarbosilanes, polycarbosiloxanes [59], and polysiloxysilanes by hydrosilylation [60], poly(ether ketones) by nucleophilic aromatic substitution [61] and polyesters [62] or polyethers by polycondensations [63] or by ring opening [64]. 

Other backbone structures that have generated interest are the polyether ketones. An attempt was made to synthesize amino-terminated arylene ether ketones, which were subsequently converted into the corresponding maleimide-terminated oligomers (37). The aim of this approach was to obtain tough, solvent resistant, high temperature BMI thermosets. 

The majority of the structures is prepared from AB2 monomers by polycondensation, to result in hb polyesters, polyamides, polyethers, poly(ester amide)s, polysulfones, poly(ether ketone)s, polyphenylenes (among others), and increasingly also by polyaddition leading to, for example, poly(carbosilane)s, poly(urea urethane)s, polyarylenes, poly(ether amide)s or polythioethers, and many others [6-11, 13, 17, 21]. In particular, cycloaddition reactions offer the advantage of an often very selective and clean, high-yield reaction that is not influenced by special functionalities [33]. The relatively easy synthesis of the hb polyphenylenes described by Mullen et al. [34]. is an excellent example of this. In addition, certain cycloaddition reactions form as Hnear units nonstable intermediates, which allows the preparation of hb polymers without any linear units, which therefore exhibit formally a DB of 100% [35]. 

The history of PEEK can be derived back to the s)mthesis of polyether ketone with the repeating unit stnicturie ofPh 0—Ph-CO-- (PEK) in 1960s. Broadly, polyetherketones can include a vast range of unit structures including ether, ketone and biphenylene units. However, the commercial PEKs consist of simple repeat units... 

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