4,4 -Dichlorodiphenyl sulphone

The kinetics of aromatic polyether formation by the reaction of bisphenol salts with 4,4 -dichlorodiphenyl sulphone was studied by Schulze and Baron [205]. The potassium salts of three bisphenols were used, with dimethyl sulphoxide solvent. The rate was considerably faster in the early stages of the reaction, when the diphenoxide was present in higher concentrations than phenoxide chain ends. The faster reaction was assumed to be... 

A polysulphone prepared from bisphenol A and 4,4 -dichlorodiphenyl-sulphone... 

Polysulphones are polymers which contain recurring sulphone groups (-SO2-) in the main chain. Aliphatic polysulphones, prepared by reaction of sulphur dioxide with olefins, have been known for many years but lack of thermal stability has precluded any commercial utilization. In 1958 the preparation of stable aromatic polysulphones was described [5] and since this time a large number of such polymers has been investigated. However, at the present time, the only aromatic polysulphone to have achieved commercial significance is that prepared from 2,2-bis(4 -hydroxyphenyl)propane (bisphenol A) and 4,4 -dichlorodiphenyl sulphone. Only this polysulphone, manufacture of which was started in 1965 by the Union Carbide Corp. (U.S.A.), is described in this chapter. 

The disodium salt of bisphenol A is pre-formed by the addition of aqueous sodium hydroxide to a solution of bisphenol A in dimethyl sulphoxide/chloro-benzene. The mixture is gradually heated to about 160°C under an inert atmosphere the water-chlorobenzene azeotrope is removed to leave an anhydrous solution of the bisphenol A salt in dimethyl sulphoxide. A solution of 4,4 -dichlorodiphenyl sulphone in chlorobenzene is then added slowly, the temperature being maintained at 160 C. Polymerization is very rapid at this temperature and can lead to a molecular weight of about 80 000 in 1 hour. In the preparation of commercial polymers, the molecular weight is restricted to 20 000—40 000 by the addition of a monofunctional chain-stopper such as sodium phenate or methyl chloride. Sodium chloride is removed from the reaction mixture by filtration and then the polymer is isolated by precipitation with ethanol. Finally, the product is dried at about 135°C. 

Photolysis of polysulphone 4.84) prepared from the polycondensation of bisphenols (e.g. 2,2-bis-(4-hydroxyphenyl)propane) with 4,4 -dichlorodiphenyl-sulphone occurs by the following mechanism [4, 79, 740] ... 

Polysulphone is obtained by condensation of bisphenolA and dichlorodiphenyl sulphone as under ... 

Beilstein Handbook Reference) 4,4 -Dichlorodiphenyl sulfone AI3-01386 AI3-02901 Benzene, 1,1 -sulfonylbis(4-ohioro- Bis(4-chlorophenyl) sulfone Bis(4-chlorophenyl) sulphone Bis(p-chlorophenyl) sulfone BRN 2052955 Di-p-chlorophenyl sulfone EINECS 201-247-9 HSDB 5233 NSC... 

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