Abstract: In a multistage counter current wash operation wherein an original solvent contained in a cake of polymeric material is displaced with a wash solvent which enters the final stage and progresses forwardly a mathematical model of the counter current wash operation is developed for providing a feedforward control system. In use, the feedforward control system maintains a desired weight fraction of the original solvent that remains in the cake exiting the final wash stage at a desired low level by manipulating the wash solvent flow rate as a function of the flow rate of the feed material. Additionally a feedback control is used in conjunction with the feedforward control.

Abstract: A process is provided to recover at least one modifier compound and at least one polar organic compound from a poly(arylene sulfide) reaction mixture comprising high molecular weight poly(arylene sulfide), low molecular weight poly(arylene sulfide), cyclic and linear poly(arylene sulfide) oligomers, at least one polar organic compound, at least one modifier compound, and an alkali metal halide by-product.

Abstract: A process is provided for curing poly(arylene sulfide) polymers by achieving and maintaining curing conditions in a cure vessel, then intermittently adding uncured polymer to said cure vessel and intermittently removing polymer from the cure vessel wherein the removal of polymer from the cure vessel is performed at intervals such that the presence of uncured polymer is minimized or avoided.

Abstract: A novel treatment and recovery process is provided which produces commercially desirable high molecular weight poly(arylene sulfide)s from undesirable low molecular weight poly(arylene sulfide)s. The novel process reduces the quantity of low molecular weight poly(arylene sulfide)s which otherwise have little or no commercial value and can require disposal.

Abstract: A process is provided for producing a poly(arylene sulfide) polymer which employs at least one base as a reactant, wherein the base is contacted with the polymerization reaction mixture incrementally during the polymerization.

Abstract: A method is provided for hydrovisbreaking hydrocarbon polymers, particularly those derived from scrap articles, in which a mixture of at least one hydrocarbon polymer and a solvent is contacted with hydrogen under conditions sufficient to hydrovisbreak the polymer. The solvent comprises a combined weight percentage of C.sub.n H.sub.2n-8 and C.sub.n H.sub.2n-10 hydrocarbons of at least about 10 weight percent, where n is an integer of at least 8 in C.sub.n H.sub.2n-8 and n is an integer of at least 10 in C.sub.n H.sub.2n-10. The hydrovisbroken polymer can be fed to a catalytic cracker for cracking to cracked products.

Abstract: Continuous production of arylene sulfide polymer is provided in a series of two or more substantially liquid-full reactors maintained at seriatim reduced temperature and pressure and discharging into a final zone which has a vapor space above a controlled liquid level and is maintained at a pressure lower than the liquid-full reaction train by vapor withdrawal with the reaction temperature increased at least to exceed all but the highest temperature in the liquid-full reactors so that at least a portion of the water produced in the arylene sulfide polymerization and a portion of the organic amide diluent are vaporized to concentrate the reaction slurry. The reaction slurry effluent from the vaporizing reactor can then be flashed with or without the aid of superheated steam dilution to produce a vapor which can be condensed, separated and recycled to the continuous reaction process and a particulate, polymeric product.