Victrex polyethersulphone

Victrex polyethersulphone was introduced in 1972 by ICL It is prepared by the self-condensation of 4,4 -dichlorodiphenylsulphone in a strong base using a high boiling point solvent. 

The first commercial polymer Table 21.3, II) was offered in 1965 by Union Carbide as Bakelite Polysulfone, now renamed Udel. In 1967 Minnesota Mining and Manufacturing introduced Astrel 360 Table 21.3, V), which they referred to as a polyarylsulfone. In 1972 ICI brought a third material onto the market which they called a polyethersulphone (III) and which they then marketed as Victrex. They also introduced a material intermediate between III and V known as Polyethersulphone 720P (IV) but which has now been withdrawn. In the late 1970s Union Carbide introduced Radel (VI), which has a higher level of toughness. Around 1986 Union Carbide sold their interest in polysulphones to Amoco. In addition the Astrel materials were produced by Carborundum under licence from ICI. 

Epikote 828 resin (Shell) cured with 4,4 -diaminodiphenylsulphone (DDS) and blended with polyethersulphone (Victrex 5003P)... 

There is, however, an Important practical difference between the reaction conditions required for successful operation of the routes to polyetherketones as compared with those for the polysulphones and this arises from a crucial difference between the two classes of polymers. Polyethersulphones are amorphous or only slightly crystalline and dissolve readily in polar organic solvents such as nitrobenzene or dimethyl sulphoxide at room temperature, but many polyetherketones develop considerable crystallinity and dissolve only at temperatures close to their melting points in this type of solvent. The insolubility of these polymers presented a major synthetic problan as it limits the molecular weights that could be obtained before the growing chains crystallised out from the polycondensation system and this is the main reason why commercial development of the polyetherketones lagged behind that of the polyethersulphones Solutions to this problem for the polyaroylation reactions, (1), were found first by du Pont and then by Raychem, while for the polyether syntheses the problem was solved by ICl. Raychem manufactured a polymer of structure 1, named Stilan, between 1972 and 1976, and manufacture of the ICI polymer, II, trade name Victrex PEEK", started in 1982. 

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