Process for the preparation of optionally branched polyarylene sulphides having reduced corrosiveness with ketone diluent and organic solvent

Process for the preparation of high molecular weight polyarylene sulphide which comprises forming a reaction mixture by reacting

• (a) 50-100 mol % of aromatic dihalogen compound corresponding to the formula:
• ##STR3## and 0-50 mol % of aromatic dihalogen compound corresponding to the formula ##STR4## wherein X represents halogen atoms in the meta or para position to each other,
• R.sup.1 is identical or different and is hydrogen, alkyl, cycloalkyl, aryl, alkylaryl, arylalkyl, or two groups each represented by R.sup.1 in the ortho position to each other are linked together to form an aromatic or heterocyclic ring, and one R.sup.1 is always other than hydrogen, and
• (b) 0 to 5 mol %, based on the sum of components (a) and (b) of an aromatic tri- or tetrahalogen compound corresponding to the formula:
• ArX.sub.n
• wherein
• Ar represents an aromatic or heterocyclic group,
• X represents chloro or bromo and
• n represents the number 3 or 4, and
• (c) alkali metal sulphide or a mixture of alkali metal sulphide with alkali metal hydroxide, 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, with the molar ratio of alkali metal sulphide (c) to the organic solvent (d) lying within the range of from 1:2 to 1:5, and
• (e) water in the form of water of hydration or free water, the molar ratio of (c):(e) lying within the range of from 1:0 to 1:3 with the process being carried out at a reaction temperature of 160.degree. C. to 270.degree. C.,
• wherein after completion of the reaction, the reaction mixture is introduced into an organic diluent comprising a ketone whereby a polyarylene sulphide precipitate is formed and the precipitate is subsequently washed.