Abstract: In the solution polymerization process wherein monomers comprising at least one conjugated diene are polymerized followed by coupling with a polyfunctional coupling agent which results in some alkyl chloride formation and solvent recovered from said polymerization is used in a subsequent solution polymerization process, the improvement comprising contacting said solvent with a molecular sieve to remove alkyl chloride therefrom before said solvent is used in said subsequent polymerization.

Abstract: An alpha-methylstyrene polymerization reaction mass is cooled by including therein a component which is readily vaporizable under the conditions of polymerization thereby to remove undesirable or excess heat, thus controlling the reaction temperature to a desired value. In one embodiment a living polymer is produced followed by addition of a second monomer to the living polymer still in solution followed by polymerization onto the living polymer, forming a living block copolymer which is coupled with a linking agent.

Abstract: Filamentary vinyl polymer compositions are commonly prepared according to the following procedure:(a) polymerizing a vinyl monomer in a concentrated aqueous inorganic salt solution to produce a vinyl polymer solution;(b) spinning the resulting vinyl polymer solution into a coagulating bath containing an aqueous solution of the same inorganic salt as that employed in the polymerization step, the concentration of inorganic salt in the coagulating bath being maintained at a level which affords precipitation of the vinyl polymer to form a coherent filamentary gel;(c) washing the gel so produced;(d) recovering the concentrated aqueous inorganic salt solution from the washing and coagulation steps; and(e) recycling the recovered concentrated aqueous inorganic salt solution into the polymerizing step. In such a process, undesirable copper ion impurities accumulate in the recovered concentrated aqueous inorganic salt solution.

Abstract: There is described an improved process for the discontinuous suspension polymerization of alkenyl-aromatic compounds, which comprises re-using the aqueous polymerization medium, after separation of the polymer beads, as the polymerization medium of a subsequent polymerization. Monomer-soluble and water-soluble initiators and, optionally fresh water and dispersing agent, are added. Re-using the aqueous polymerization medium does not negatively affect the color and mechanical properties of the polymer obtained. The process of the invention results in considerable saving of energy.

Abstract: Improved continuous process for synthesis of cis-1,4 poly(isoprene). In the commercial process for synthesis of cis-1,4 poly(isoprene) only a portion of the monomer charged is polymerized. The polymer, thus obtained, is separated from the unreacted monomer which in turn is recycled with solvent back into the system for conversion to additional polymer. Fresh monomer must be added from a separate feed to this recycle stream in sufficient quantity to replace or "make-up" for that which was converted to polymer. In the improved process of this invention, this "make-up" isoprene monomer is dried and then is introduced into the process subsequent to the initiation of polymerization of the isoprene monomer already present within the system, but prior to deactivation of the polymerization catalyst. Dehydration of "make-up" isoprene prior to its introduction into the process stream at the above juncture avoids deactivation of the still active catalyst with water.

Abstract: Vapor phase polymerization of an olefin which comprises conveying inactive high yield titanium catalyst component to a vapor phase polymerization reactor with a liquid comprising recycled quench liquid, reactivating said inactive high yield titanium catalyst component inside the reactor with a metal alkyl reducing agent and polymerizing olefin under gas phase polymerization conditions with reactivated high yield catalyst to form a resinous polymer of an olefin having a low level of catalyst residues.

Abstract: Apparatus and process is herein disclosed by which a polymerizable monomer or mixture thereof can be economically and efficiently converted to polymeric substances with a high yield catalyst and, optionally, co-catalyst by a vapor phase, essentially isobaric, polymerization process using a horizontal, stirred-bed, quench-cooled, essentially total reactor off-gas recycle reactor.

Abstract: In conventional olefin polymerization using TiCl.sub.3 -containing Ziegler type catalysts, the catalyst-containing reaction product may be de-ashed by treatment with titanium-solubilizing compounds such as alcohols and the polymer product from the de-ashing step washed with a hydrocarbon to separate it from catalyst residue. It is desirable to treat the dirty hydrocarbon wash liquid to recover purified hydrocarbon suitable for recycle to the polymerization reaction. According to this invention the dirty hydrocarbon wash liquid is treated with an epoxy compound in the presence of an alcohol and distilled to recover purified hydrocarbon suitable for recycle.

Abstract: A process for cooling a polymerization reaction of compounds in a dispersion and/or solution involves evaporation of one or more liquids contained in the dispersion and/or solution, condensation of the vapors in a reflux condenser, and recycling of the thus-condensed vapors into the reactor, together with the use of a controllable flow of coolant which is introduced into the reflux condenser jacket. In this process the amount of heat given off during condensation serves as the control variable for a controller for controlling the input of cooling medium for the reflux condenser.

Abstract: The fouling of autorefrigeration polymerization systems because of entrained particles in the vaporized solvent-diluent is substantially reduced by returning the recycle solvent-diluent into the reaction zone through nozzles which provide a solvent-diluent spray of an average droplet size of less than 1000 microns, preferably between about 225 and 300 micron average particle size, which spray removes major amounts of entrained particles down to 5 microns in size. The solvent diluent may be an inert material or unreacted alpha-olefin, such as propylene.

Abstract: Novel rubbery polymer having a uniform and broad molecular weight distribution, a ratio of weight average molecular weight to number average molecular weight of 3 or more, a content of monovinyl aromatic compound of 0 to 30% by weight, a bonding manner of conjugated diolefin of 60% or more of 1,4-linkage and improved processability and physical properties can be obtained by circulating living polymer in the polymerization or copolymerization of conjugated diolefins or copolymerization of conjugated diolefin and monovinyl aromatic hydrocarbon carried out with a lithium-based catalyst.

Abstract: A desiccant regeneration system is disclosed which employs polymerization diluent as regeneration medium for monomer recycle desiccant driers in ethylene-alpha olefin copolymerizations and utilizes existing diluent purification systems (i.e., systems employed in polymerization processes for diluent recycle), thereby avoiding separate regeneration facilities, providing high purity regeneration fluid and allowing regeneration at relatively mild temperatures.

Abstract: A continuous process for recycling hydrogen for reuse in making blends of olefin copolymers of high and low molecular weights which comprises copolymerizing ethylene with at least one higher olefin monomer in a solvent in separate reactors in the presence of a coordination catalyst, at least one, but not all, of said reactors containing hydrogen in an amount sufficient to produce low molecular weight copolymer. The resulting solutions of high and low molecular weight copolymers are mixed, unreacted monomers and hydrogen are flashed from the mixture, and the copolymer blend is isolated from the unflashed residue.

Abstract: A method is herein disclosed by which a polymerizable monomer or a mixture thereof can be economically and efficiently converted to polymeric substances with a high yield catalyst in a vapor phase polymerization process using a stirred-bed, quench-cooled, horizontaL reactor together with essentially total reactor off-gas recycle and melt finishing. The method is further characterized by being essentially isobaric at least up to the polymer finishing steps.

Abstract: A cyclic process is provided for the polymerization and hydrogenation of certain polymers wherein the monomer is anionically polymerized in solution, the living polymers then being terminated by the use of a proton donor, after which the polymer is subjected to catalytic hydrogenation wherein the catalyst is optionally activated with certain polar compounds after which the polymer is coagulated and heated to remove any residual terminator and activator and the solvent is fractionally distilled to recover and recycle the solvent without contamination from the substantially higher boiling terminator and optional activator.

Abstract: A propylene oxide slurry polymerization process having high catalyst efficiency comprises (A) homopolymerizing or copolymerizing propylene oxide in isobutane in the presence of a catalyst substantially soluble in isobutane, (B) separating isobutane with catalyst dissolved therein from propylene oxide polymer, and (C) recycling isobutane and dissolved catalyst for further polymerization. The catalyst comprises (1) at least one trialkylaluminum compound wherein each alkyl group contains from 2 to 10 carbon atoms, (2) at least one diketone containing from 5 to 20 carbon atoms and (3) water. The catalyst may also contain (4) at least one dialkyl ether or cycloalkyl ether containing from 2 to 12 carbon atoms and/or (5) at least one ether alcohol containing from 2 to 12 carbon atoms.

Abstract: A process is provided for recovering hexane from the mixed recycle stream from a plurality of ethylene polymerization reactors. The recycle stream containing hexane and periodically vinyl acetate and/or an alkyl acrylate admixed with vinyl acetate to provide a mixed feed stream containing at least 45% by weight vinyl acetate. This feed stream is distilled at atmospheric pressure and all of the hexane is recovered as an overhead azeotrope containing about 57% hexane. The overhead fraction is redistilled at a superatmospheric pressure of at least 4 atmospheres in a second column. The overhead fraction of the second column will be enriched in vinyl acetate and pure hexane is recovered as a bottoms fraction from the second column. The vinyl acetate and/or alkyl acrylate contained in the bottoms fraction of the first column is recovered by atmospheric distillation in a third column.

Abstract: A melt finish process is disclosed herein for working up solid, particulate polymer from a vapor state polymerization reactor, which reactor employs high yield catalysts, whereby the polymer is moved out of the reactor and into a post polymerization zone characterized by essentially adiabatic polymerization and the heat of such polymerization is used in raising the temperature of and melting said solid, particulate polymer to form molten polymer for further processing.