Abstract: The invention relates to the purification of polymers, particularly resorbable polyesters, using shear fields produced mechanically or by fluid dynamics.

Abstract: A polymer hydrogel substantially free from monomers and oligomers is prepared by contacting a previously prepared polymer hydrogel with a single-phase mixture of water and a solvent and then separating the mixture of water and solvent from the hydrogel.

Abstract: A polyarylene sulfide having a low content of electrolytic ions is economically recovered from a mixture consisting mainly of polyarylene sulfide and an alkali metal halide which mixture is obtained by reacting a polyhalogenated aromatic compound and an alkali metal sulfide containing water in an organic polar solvent, by dehydrating the mixture by distillation, mixing the dehydrated mixture with a solvent which is a poor solvent for both polyarylene sulfide and alkali metal halide and which is soluble in the organic polar solvent to prepare a slurry consisting essentially of the polyarylene sulfide and the alkali metal halide, subjecting the slurry to solid-liquid separation, washing the resultant cake with the poor solvent, drying the cake, adding water to the cake to wash away the alkali metal halide through dissolution, and subjecting the slurry to solid-liquid separation to recover polyarylene sulfide.

Abstract: Phenolic impurities are removed from polyaryloxyphosphazenes by extracting a solution of the crude polyaryloxyphosphazene with an aqueous lower alcohol alkali metal base solution such as aqueous methanolic sodium hydroxide.

Abstract: The invention is a process for reducing catalyst residues from a Group VIII metal compound-containing polymer of CO, ethylene and optionally at least one of olefinically unsaturated hydrocarbon. The process comprises contacting the polymer with an effective amount of a bidentate phosphine ligand having the general formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 represent hydrocarbon groups which may contain polar or non-polar substituents and R represents a bivalent organic bridging group containing at least two carbon atoms in the bridge.

Abstract: The molecular weight distribution of polytetrahydrofuran and of copolymers of tetrahydrofuran and alkylene oxides is narrowed by a process in which the polymers are mixed with a solvent mixture consisting of (a) an alkanol, (b) a hydrocarbon and (c) water, the content of the individual components a, b and c in the mixture being from 8 to 60% by weight, after which the three phases formed are separated from one another and the polymer having the narrower molecular weight distribution is isolated from the two lower phases.

Abstract: A process for achieving a high yield of rubber and/or resin from rubber containing plants such as guayule plants by crushing the plants, forming a slurry with a solvent and fine grinding said slurry with a high shear mixer. The time required by the process is very short in comparison with prior art techniques.

Abstract: A precipitation procedure for preparing pulverulent coating compositions of high molecular weights by post condensation and based on polyamides having at least ten aliphatically bound carbon atoms per carbonamide group. The starting materials are uncontrolled polyamides having a relative solution viscosity of between 1.7 and 2.0 (measured in 0.5% meta cresol solution at 25.degree. C.) and contain not more than 0.2% by weight of phosphoric acid. After the cooling stage of the precipitation step of the polyamides, from 0.3 to 1.2% by weight of phosphoric acid referred to the polyamide are dispersed in the suspension prior to the precipitation in the solution or after the precipitation stage.

Abstract: Coating powders for the melt film coating method, based on polyamides and adhesion improving additives. The polyamides are aliphatic homo- and/or copolyamides having at least six carbon atoms containing functional groups consisting of at least 80% of primary, secondary, or mixtures of primary and secondary amino groups. As the adhesion improving additive there is added from 0.1 to 10% by weight referred to the polyamides of an isophoronediisocyanate capped with lactams, an isophoronediisocyanate capped with acetonoxime or an isophoronediisocyanate capped with an oligomer of acetonoxime.

Abstract: An improved process for preparing pulverulent coating compositions pigmented with titanium dioxide and based on polyamides having at least ten aliphatically bound carbon atoms per carbonamide group using the precipitation method. The titanium dioxide pigments used are without nucleating effects or only have weak nucleating effects on the polyamide precipitation. The pigments have nucleating effects less than or equal to 3.degree. C. where .DELTA.T=(T.sub.max p)-(T.sub.o). T.sub.max p is the maximum temperature at which precipitation takes place in a solution of polyamide having pigment therein and T.sub.o is the maximum temperature at which precipitation takes place in polyamide solution having no pigment therein.

Abstract: Polyamide based coating powders having a practically uniform grain size distribution are prepared employing the precipitation procedure provided that the polyamide is dissolved in ethanol at 127.degree. to 135.degree. C. and that the solution is cooled while distilling the ethanol in such a manner that the reactor jacket temperature does not drop below the temperature of the reactor contents until the end of the precipitation stage.

Abstract: The invention concerns an improved precipitation process in the manufacture of coating powders based on polyamides having at least ten aliphatically bound carbon atoms per carbonamide group. Rapid cooling takes place with stirring mainly by distilling the ethanol solvent until the temperature of precipitation is set in the range from 90.degree. to 113.degree. C. With the beginning of the saturation limit (about 125.degree. C.), the temperature difference between the coolant in the jacket and the solution inside is maintained at most at .+-.3.degree. C. The solution is maintained during the precipitation stage at constant temperature (isothermal procedure) by further distillation of the ethanol.

Abstract: A process for extracting rubber and/or resin from rubber containing plants such as guayule utilizing a monophase mixture of an organic polar solvent and a hydrocarbon solvent.

Abstract: A process for separating cyclic oligomeric dihydric phenol carbonate from high molecular weight linear aromatic polycarbonate which comprises admixing a solution of aromatic polycarbonate and oligomeric dihydric phenol carbonate in a halogenated organic solvent with an antisolvent selected from the group consisting of butanol, isobutanol and an alkane of from five to about nine carbon atoms, inclusive, separating the solid aromatic polycarbonate from the solution of cyclic oligomeric dihydric phenol carbonate, increasing the antisolvent to halogenated organic solvent ratio and thereby precipitate the cyclic oligomeric dihydric phenol carbonate.

Abstract: A process for preparing a polycyanoaryl ether powder which comprises;reacting at a temperature between 100.degree. and 350.degree. C. a dihalogenobenzonitrile with an alkali metal salt of at least one of hydroquinone and dihydroxydiphenyl in the presence of a solvent (i) selected from the group consisting of dimethyl sulfoxide, diethyl sulfoxide, sulfolane, N-methylpyrrolidone, N-methylacetoamide and N-methylformamide to form a reaction mixture containing a dissolved polycyanoaryl ether; andwhen the concentration of said dissolved polycyanoaryl ether in the reaction mixture is in the range of from 2 to 15% by weight, adding to said reaction mixture, a solvent (ii) which is miscible with said solvent (i) but which is not a solvent for said polycyanoaryl ether, said solvent (ii) being added in an amount of from 30 to 200% by volume based on the volume of said solvent (i) and said solvent (ii) being added at a temperature of from 10.degree. to 100.degree. C.

Abstract: The invention relates to a new polyacrylamide adhesive suitable for the fixing of fine-particle sorbent layers based on organic and/or inorganic compounds, used in overpressured one- and multilayer chromatographic procedures.The said adhesive is prepared by polymerizing the aqueous solutions of acrylamide and N,N'-methylene-bis-acrylamide in the presence of a catalyst pair at from 21.degree. to 30.degree. C., pulpifying the precipitate thus obtained and repeating the precipitation and the pulpification more times.

Abstract: A process is provided herein wherein a solid polymer slurry diluted with a specific diluent is continuously discharged under controlled conditions from a high pressure zone to a low pressure zone substantially maintained at atmospheric pressure and the slurry is then separated into said diluent and dried polymer, the improvement wherein the discharged amount of the solid polymer slurry is strictly controlled by varying the heat in the second zone and simultaneously adding a diluent which is gaseous under normal temperature and pressure so that by the control of these two perimeters a continuous slurry discharge can be maintained at predetermined levels.

Abstract: A formed product of a high molecular compound having a glass transition temperature of not more than about 60.degree. C., which is substantially free of halogenated solvents harmful to the human body, is produced by mixing the high molecular compound, a halogenated solvent and an organic solvent other than the halogenated solvent which is compatible with the solvent and is less apt to dissolve the high molecular compound to prepare a solution and then maintaining the solution at a temperature around the boiling point of the halogenated solvent.

Abstract: A method of isolating polymer resins from organic solvents is provided wherein the organic solvent is volatilized in the presence of an aqueous slurry of solid polymer particles of a particular size which provide agglomeration sites for the polymer resin within solution. The process can function continuously with various polymers including polycarbonates, polystyrene, polyetherimides, polyphenylene ethers, polyesters, etc.

Abstract: Disclosed is a process for modifying accumulated cross-linked polymer in an apparatus used for the production of a vinylaromatic compound, comprising optionally softening the polymer with an organic solvent; precipitating the polymer with a light, polar non-solvent for the polymer and expanding the softened polymer by bringing the softened polymer in contact with steam whereby the polymer is converted into a state which enables it to be more easily removed from the apparatus.

Abstract: A continuous process for the extraction of 3-hydroxybutyrate polymers from micro-organism cells wherein a non-solvent is added to the extracted syrup to permit separation of the polymer and, by distillation, the bulk of the extraction liquid, which may be a solvent/non-solvent mixture, is recovered for re-use. Preferably the non-solvent added to the syrup is also recovered in the distillation.

Abstract: Improved rate of dissolution in liquid hydrocarbon fuels, of specified tert-butylstyrene copolymers capable of imparting anti-misting characteristics to the fuel, is obtained when the copolymer, following its production by aqueous emulsion polymerization of the monomers, is isolated from the resulting latex by a process of flocculation, separation, washing and drying at moderate temperatures. The copolymer thus isolated is advantageously incorporated in the liquid fuel in the form of a slurry with a hydroxylic liquid and an amine.

Abstract: A method for making a quite finely divided particulate copolymeric perfluorocarbon having pendant cation exchange functional groups, and having an equivalent weight of at least in excess of 900 but not greater than about 1500. In the method, the perfluorocarbon copolymer is solvated in a solvent and then precipitated from solution by addition of a substance miscible in the solvent but having essentially no capability for solvating the perfluorocarbon copolymer. The method is conducted at a temperature generally below about 300.degree. C.

Abstract: A continuous process for the preparation of polymer compositions having low volatile content which comprises passing a styrene polymer-containing polymerization fluid composition obtained by solution polymerization or bulk polymerization through a volatile component separator comprising vertical foaming preheaters and vacuum vessels directly connected therewith and thereby removing volatile components continuously from the polymerization fluid composition in three stages to obtain a polymer composition having low volatile content, the process being characterized in that each of three stages includes at least one vertical foaming preheater and one vacuum vessel, the first stage is carried out under such pressure and temperature conditions that the polymerization fluid composition leaving this stage contains said styrene polymer in an amount of 60 to 80% by weight and the temperature of the polymerization fluid composition passing through this stage lies between 70.degree. and 120.degree. C.

Abstract: A method is provided for reducing the solvent content and increasing the sticking temperature of polyvinyl alcohol, which is prepared from the alcoholysis of polyvinyl acetate, charged to a dryer. The polyvinyl alcohol from the alcoholysis reaction, without prior vacuum drying at an elevated temperature, is slurried in a liquid medium comprising methanol, methyl acetate, water and, optionally, a nonsolvent for polyvinyl alcohol. The slurry is heated to at least 60.degree. C. for at least 5 minutes. The polyvinyl alcohol burnt particle count is reduced in the subsequent drying step and a product is afforded which has a reduced ash content and increased cold water solubility and low temperature solubility.

Abstract: Benzene is removed from carboxy polymethylene resin by dissolving the resin to form a solution and dispersing the solution as fine droplets in a gas phase or aerating the solution to introducing into it a fine dispersion of gas bubbles. The benzene transfer from the solvated resin to the gas phase and a benzene-free resin or solution can be obtained which may be usable in pharmaceutical and food products.

Abstract: A process for the continuous glycolytic cleavage of polyurethane plastics waste in multi-shaft screw machines by the addition of optionally preheated diols, at a degradation temperature of 250.degree. C., while maintaining a pressure at least such that the polyurethane-diol mixture is in the liquid phase, by the discharge of the glycolysate mixture after short residence times of from 2 to 30 minutes in the reaction screw, and by rapid cooling of the glycolysate mixture.

Abstract: Polypropylene powder is produced by dissolving polypropylene in a solvent mixture at an elevated temperature, cooling the solution to below about 80.degree. while maintaining it in quiescent condition for precipitation of the polypropylene as particles which are composed of polypropylene grains, separating the precipitate, drying, and subjecting the dry particles to mechanical comminution.

Abstract: An improved method for the production of polyphenylene ethers is disclosed. The method comprises oxidatively coupling monohydric phenols in the presence of a complex catalyst and in a liquid medium which is a solvent for the monomer and catalyst and a non-solvent for the polyphenylene ether. The polyphenylene ether precipitates to form a slurry of particulate solids which is then washed with an aqueous solution of a chelating agent to remove catalyst residue.

Abstract: In the preparation of a high molecular weight polyphenylene ether from a monohydric phenol by an oxidative coupling reaction with oxygen in the presence of a catalyst complex obtained from a metal salt and an organic amine and in the presence of a solvent, and isolation of the metal ion component of the catalyst from the polyphenylene ether solution by means of a complex-forming or chelate-forming compound, the catalyst is removed by a method wherein complex formation and isolation of the metal ion component of the catalyst are carried out in an aqueous medium in the presence of from 0.1 to 5,000 mg of an anionic or non-ionic surfactant.

Abstract: Disclosed is a process for modifying accumulated cross-linked polymer in an apparatus used for the production of a vinylaromatic compound, comprising optionally softening the polymer with an organic solvent; precipitating the polymer with a light, polar non-solvent for the polymer and expanding the softened polymer by bringing the softened polymer in contact with steam whereby the polymer is converted into a state which enables it to be more easily removed from the apparatus.

Abstract: Rubber, hydrocarbons, i.e., resins, and other useful by-products are extracted, recovered and isolated from shrubs such as guayule and guayule-like shrubs by a procedure wherein the entire non-defoliated shrub, after being comminuted, is processed in an aqueous and/or a non-aqueous system. An optional water treatment step can be used to remove water solubles and/or facilitate processing and achieve increased yield of desired by-products.

Abstract: A polymer is precipitated from a cement containing the polymer dissolved in a nonpolar solvent by mixing the cement with a nonsolvent alcohol and water wherein the relative amount of water to the alcohol is different from the alcohol/water azeotropic composition and being such as to produce a polymer product in the form of discrete particles, the product having bulk density in excess of 0.08 g/cc or 5 lb/ft.sup.3, is capable of being easily filtered and dried, and is a polymer of a monomer that contains at least one norbornene group.

Abstract: Removal of acrylonitrile from latex by azeotropic distillation with methanol.

Abstract: Process for precipitating a polycycloolefin from polymer cement comprising mixing said cement with a sufficient amount of a lower alcohol and water precipitant to cause said polymer to precipitate, and separating said polymer from the remaining liquid phase, the polymer cement having about 15 to 80% solids concentration and being a honey-like solution in a nonpolar hydrocarbon solvent of a polymer formed by ring opening polymerization of at least one monomer containing at least one norbornene group. The precipitation process can be either batch or continuous throughout.

Abstract: Precipitation of a polymer from polymer cement containing about 15 to 80% solids is accomplished by mixing the cement with water and a nonsolvent near or above the boiling point of a ternary azeotrope whereby the polymer precipitates forming a slurry and the ternary azeotrope is withdrawn as a vapor, separating the polymer from the liquid phase and recycling the liquid phase to the mixing step, the polymer cement being a honey-like solution in a nonpolar solvent of a polymer prepared by ring opening polymerization in the nonpolar solvent of at least one cyclic olefin containing at least one norbornene group, the nonsolvent is selected from lower alcohols that form binary azeotropes with water, and the ternary azeotrope comprising the nonpolar solvent, the nonsolvent, and water. The process can be operated either in batchwise segments or continuously throughout.

Abstract: Solid copolymers of butene-1 and 4-vinylcyclohexene prepared by copolymerizing the monomers in the presence of a titanium halide coordination catalyst have an unobvious balance of properties including a broader molecular weight distribution, shorter crystallization half-time, greater isotacticity and greater crystallinity than butene-1 homopolymers prepared with identical catalysts.

Abstract: Precipitation of polymer from a polymer cement comprising the polymer dissolved in cyclohexane is accomplished by mixing the cement with methanol whereby the polymer precipitates forming a polymer slurry comprising polymer solids dispersed in cyclohexane and methanol, heating the polymer slurry to vaporize methanol and cyclohexane in azeotropic proportion, condensing the vaporized methanol and cyclohexane whereby it separates into an upper phase that is nearly all cyclohexane and a lower phase that is rich in methanol, separating the phases, and separating the polymer from the residual slurry comprising polymer solids dispersed in methanol, the polymer being a reaction product formed by ring opening polymerization of at least one monomer containing at least one norbornene group. The process can be conducted in batchwise segments or continuously throughout.

Abstract: Method for removing chlorinated solvents from chlorinated polymers which retain them as a result of a chlorination process, wherein after being dried and pulverized, said chlorinated polymer is treated with a non-halogenated aliphatic organic solvent or a halogenated aromatic organic solvent. Said organic solvent pertains to the following groups: alcohols such as methanol, ethanol, isopropanol; esters such as methyl formate, ethyl formate, methyl acetate; nitriles such as acetonitrile; aromatic halides such as chlorobenzene; hydrocarbons such as n-hexane; and acetone.

Abstract: Insulating wire coating enamels containing a mixture of polyvinyl acetal, phenolic and epoxy resins are prepared by precipitating the resins from a tetrahydrofuran solution with water. The precipitated resins are dried and electrostatically applied to transformer wire.

Abstract: A saponified ethylene-vinyl acetate copolymer composition, improved in behavior in the molten state, which comprises: a saponified ethylene-vinyl acetate copolymer, with an ethylene content of 20-80 mole percent and a saponification degree of at least 85 percent, and 0.00005 to 0.005 percent by weight, based on said copolymer, of manganese, copper or mixtures thereof; said composition, when extracted with pure water, giving an acidic extract, is disclosed, along with a method of making the same.

Abstract: Poly (.beta.-hydroxy butyric acid), PHB, is extracted from a suspension of bacterial cells by causing the cells to flocculate, by pH modification, optionally with heating, and then extracting the PHB from the flocculated cells with a suitable extraction solvent. Flocculation of the cells renders subsequent separation of the PHB solution from the cell debris more facile. Preferably lipids are extracted from the flocculated cells before contact with the PHB extraction solvent.

Abstract: A method of precipitating a copolymer comprising maleic anhydride from a solution comprising an organic solvent, the method comprising mixing a solution of an organic solvent and a copolymer of maleic anhydride and a monomer copolymerizable therewith with hot water and agitating the resulting mixture for a sufficient period of time and at a sufficiently high shear rate to yield precipitated particles of said copolymer that are substantially free of internal organic solvent.

Abstract: A thermoplastic polymeric material comprises a copolymer which is a poly(bisphenol A tere- and/or isophthalate) copolycarbonate having a molar ratio of phthalate to carbonate units in the inclusive range from 2 to 10, preferably 3 to 8. The material, which may be prepared by techniques which are known, may be used in applications for high temperature transparent thermoplastics, eg transparencies for the aerospace industry.

Abstract: Polymeric soaps prepared from copolymers of hydrophobic monomers and hydrophilic monomers are useful as granulation and/or drying aids for polymeric gels, especially those gels of polyacrylamide.

Abstract: Polyamide powder coating compositions for the coating of metals at high temperatures are obtained by the precipitation method from polyamides having at least 10 aliphatically bound carbon atoms per carbonamide group, copolyamides having at least 70% of these polyamides and mixtures of homopolyamides and copolyamides having at least 70% of these polyamides.A. For the preparation of powder coating compositions useful in the fluidized bed coating method the polyamides with 10 or more carbon atoms and having a relative viscosity between 1.4 and 1.8 are added to at least twice the amount by weight of ethanol and while the mixture is being mechanically mixed in a closed vessel is converted into a solution at temperatures between 130.degree. and 150.degree. C. This solution is adjusted to a precipitation temperature of between 100.degree. and 125.degree. C. while avoiding the formation of local sub-cooling and is agitated under an inert gas atmosphere to suppress boiling.

Abstract: A process for the preparation of dispersions of optionally cross-linked ethylene-vinyl ester graft polymers wherein an ethylene-vinyl ester copolymer is used as graft substrate and a vinyl ester of a C.sub.1 -C.sub.18 carboxylic acid and/or a C.sub.1 -C.sub.10 -alkyl ester of acrylic and/or methacrylic acid are used as a graft monomer which is polymerized, optionally together with a cross-linking agent having two or more C--C double bonds, in organic solution until at least 25% by weight of the graft monomer has been reacted, the reaction product is converted into a stable finely divided dispersion by the addition of a precipitating agent under the action of shearing forces and polymerisation is completed before, during or after the formation of the dispersion.

Abstract: Polyolefin polymer powder containing active catalyst residues is deactivated by (1) purging with an inert gas containing water vapor and (2) then contacting such powder with a gas mixture containing an inert gas, water vapor, and a third component selected from the group consisting of oxygen, carbon monoxide, carbon dioxide, C.sub.1 -C.sub.4 alcohols and C.sub.2 -C.sub.4 alkeneoxides.

Abstract: A process for purifying an acetylene-terminated polyimide oligomer containing residual solvent in which the oligomer is initially dissolved in the same solvent used as the reaction medium in its synthesis. After precipitating the oligomer from solution by mixing with an aqueous solution of potassium or sodium chloride, the precipitated oligomer is washed successively with a plurality of liquids of decreasing polarity to provide an oligomer free of residual solvent.

Abstract: The tensile strength of shaped articles made from arylene sulfide/sulfone polymers is increased by treating the article with an organic liquid at an elevated temperature. In one embodiment, the organic liquid comprises at least one of selected hydrocarbons, alcohols, and esters.