Process for the preparation of high molecular weight, optionally branched polyarylene sulphides

Claim 1

In an improved process for the preparation of high molecular weight polyarylene sulphide by reacting: (a) 50-100 mol-% of dihalogenated aromatic compound corresponding to the formula ##STR3## and 0-50 mol-% of dihalogenated aromatic compound corresponding to the formula ##STR4## wherein X represents halogen in the meta- or para-position to each other and R 1 , which may be identical or different, represents hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl, and two of the R 1 groups in the ortho-position to each other may be linked together to form an aromatic or heterocyclic ring, and one R 1 always represents a substituent other than hydrogen, and (b) 0 to 5 mol-%, based on the sum of components (a) and (b), of a tri- or tetra-halogenated aromatic compound corresponding to the formula ArX.sub.n wherein Ar represents an aromatic or heterocyclic group, X represents chlorine or bromine and n represents the integer 3 or 4, and (c) alkali metal sulphide or alkali metal sulphide mixed with alkali metal hydroxides, the molar ratio of (a+b):c lying in the range of from 0.85:1 to 1.15:1, and (d) an organic solvent wherein the molar ratio of alkali metal sulphide (c) to the organic solvent (d) lies within the range of from 1:2 to 1:15, the improvement comprises heating a mixture of reactants which are anhydrous to 150° to 205° C., whereupon the reactants containing water are then added at such a rate that the water introduced with the water-containing reactants is distilled off continuously to thereby obtain and maintain an anhydrous reaction mixture and subsequently conducting the reaction in the absence of water at temperatures of from 210° to 270° C.