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

Claim 1

A process for the production of a high molecular weight polyarylene sulfide comprising first, forming a reaction mixture of (a) 50 to 100 mol % of a first dihaloaromatic material corresponding to the formula: ##STR3## and 0 to 50 mol % of a second dihaloaromatic material corresponding to the formula: ##STR4## wherein X are halogen in the meta- or para- position to one another, and R 1 can be the same or different and is hydrogen, alkyl, cycloalkyl, aryl, alkylaryl, arylalkyl, or two radicals R 1 in the ortho- position to each other linked together to form an aromatic or heterocyclic ring and one radical R 1 is invariably other than hydrogen, (b) from 0 to 5 mol %, based on the sum of components (a) and (b), of a tri-or tetra-haloaromatic material corresponding to the formula: ArX.sub.n wherein Ar is an aromatic or heterocyclic radical, X is halogen, and n is 3 or 4 (c) an alkali metal sulfide or mixture thereof with an alkali metal hydroxide, the molar ratio of (a+b):c being from 0.85:1 to 1.15:1, and (d) a polar organic solvent or mixture thereof with a catalyst, the molar ratio of the alkali metal sulfide (c) to the polar organic solvent (d) being from 1:12 to 1:15, and removing substantially all the water from the reaction mixture and second, reacting the dehydrated reaction mixture at a temperature from 160° to 270° C. in a vessel cascade comprising 2 to 6 vessels, where the reaction temperature is continuously raised over the individual reaction vessels.