Sulfonated polyarylether ketones

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. 

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. 

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. 

In order to enhance the sulfonic acidity and therefore improve the polymer proton conductivity, a different synthetic pathway has been elaborated to introduce the sulfonic acids in the ortho position to electron-withdrawing groups (sulfones, ketones). Based on a procedure widely developed by Jan-nasch et al. for the synthesis of proton exchange polyarylethers [82,83], Chen et al. [84] designed an original and interesting monomer (Fig. 9). However, the harsh experimental conditions required (BuLi, gaseous SO2) and relatively low overall yields (24.7%) should preclude the wide development of such monomers. 

Considerable attention has been devoted to the preparation of fluorine-containing polymers because of their unique properties and high temperature performance (I). Recently we reported the preparation and characterization of novel fluorine-containing polyimides and polyethers which exhibit low moisture absorption and low dielectric constants (2, 3). Fluorinated polyimides absorb 1 wt% water and have dielectric constants of about 2.8 (all dielectric constants reported in this paper were measured at 10 kHz) vtdiereas their non-fluorinated analogs absorb as much as 3 wt% water and have dielectric constants of about 3.2. Fluorinated polyarylethers, which are free of polar groups such as ketones, imides and sulfones, absorb as little as 0.1 wt% water and have dielectric constants less than 2.8. 

Almost simultaneous with the report of the preparation of polyarylether sulfones, aromatic polyether ketones were prepared via the Ni(0) catalyzed polymerization of aromatic ether ketones with chloro groups at each terminus (equation 53) (181). The reaction proceeds rapidly under mild conditions. 

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