Silicon-containing polymers

An aromatic polymer is prepared by heating an aromatic sulphonyl halide containing at least two sulphonyl halide groups with a silicon-containing aromatic substance having replaceable nuclear hydrogen atoms under such conditions that SO2 and HC1 are evolved. The number of mols. of the Si-containing aromatic substance per mol. of aromatic sulphonyl halide is not greater than the number of SO2Cl groups in the sulphonyl halide. Examples of suitable sulphonyl halides are: benzene-1,3-disulphonyl chloride; biphenyl-4,41-disulphonyl chloride; and diphenyl ether-4,41-disulphonyl chloride. The aromatic silicon containing compound may contain more than one aromatic nucleus and may be a cyclic or linear oligomeric aromatic siloxane. It may be a polymer formed from repeating units where Z and Z1 each represent monovalent aromatic radicals and Ar is a divalent aromatic radical. The starting material may have a molecular weight of 1000 to 10,000 and reaction may take place at 200-375 DEG C. A catalyst may be used, e.g. copper and copper halides (see Specification 959,605). Examples relate to polymers prepared from (i) octaphenylcyclotetrasiloxane and benzene-1,3-disulphonyl chloride, (ii) a condensation polymer of diphenyldichlorosilane and hydroquinone with benzene-1,3-disulphonyl chloride, (iii) condensation polymers of diphenyldichlorosilane and resorcinol of varying molecular weight with benzene-1,3-disulphonyl chloride.