Abstract: This invention relates to an improved process for the batch polymerization, neat, of a monomer system comprising N-vinyl pyrrolidone monomer utilizing an oil soluble,-thermally activated, free radical initiator. The improvement for reducing the monomer level from about 1 to 2% by weight of the polymerization product to a level below about 0.2 and preferably below about 0.1% by weight of the polymerization reaction product comprises continuously adding an oil soluble azo type free radical generating catalyst to the polymerization reaction product and establishing and maintaining the polymerization reaction product containing residual monomer at a temperature and for a time sufficient to effect substantial polymerization of the residual monomer. Typically the oil soluble, azo type free radical generating catalyst is azobis(isobutyronitrile).

Abstract: This invention relates to a short residence time polymerization reactor operating in periodic mode with multiple catalyst feeds and staged monomer feeds operating to minimize off specification product and optimize and control molecular weight and molecular weight distribution of the polymer produced. This invention contemplates the polymerization of olefins particularly alpha-olefins, particularly ethylene and propylene into homo, co and terpolymers.

Abstract: A 1,2-polybutadiene composition having an excellent reinforcing effect for rubber and synthetic resin materials including at least two polybutadiene components different in melting point from each other and each having, as a main structure, a 1,2-polybutadiene structure, produced by polymerizing a 1,3-butadiene-containing monomer in a water-containing polymerization system in the presence of a catalyst comprising a transition metal compound, an organic compound of one of the Group I to III metals, and one of carbon disulfide, phenyl isothiocyanate, and xanthic acid compounds, while adding a melting point-regulating agent comprising at least one of ketones, aldehydes, alcohols, esters, nitriles, sulfoxides, amides, and phosphoric acid esters in one or two or more separate adding operations or a continuous adding operation.

Abstract: An improved process for making vinyl aromatic/allylic alcohol copolymers is disclosed. Gradual addition of a free-radical initiator during the course of the polymerization results in a substantial increase in the polymer yield obtained compared with the yield from conventional processes in which all of the free-radical initiator is charged initially. The process is particularly useful for making commercially important varieties of styrene-allyl alcohol copolymers.

Abstract: Simultaneous control of the molecular weight and the molecular weight distribution in the production of toner resins can be accomplished by using a starve fed emulsion polymerization process, which includes: selecting a desired molecular weight and molecular weight distribution of the polymer resin; determining a starve fed fraction to achieve the desired molecular weight and molecular weight distribution; and charging a reaction vessel with a chain transfer agent and a first monomer emulsion, and polymerizing monomer in the first monomer emulsion while simultaneously adding to the reaction vessel additional monomer, in the form of a second monomer emulsion, and additional chain transfer agent. The resins thus produced may be used in dry toners, liquid developers and inks suitable, for example, for ink jet applications.

Abstract: According to the present invention, in a vapor phase polymerization of olefins, there is provided an efficient polyolefin manufacturing process capable of preventing the formation of a sheet-like polymer and allowing an olefin polymerization reaction to be started stably.

Abstract: An improved process for making allyl polymers and copolymers is disclosed. Conversions of the allyl monomers are substantially increased by adding the free-radical initiator gradually during the polymerization. The process is particularly useful for making polymers and copolymers from common allyl monomers such as allyl alcohol, allyl acetate, and propoxylated allyl alcohol.

Abstract: A one step process for the preparation of toner compositions which comprises adding to an extruder a base resin, initiator, pigment, and optional charge enhancing additive; effecting crosslinking of the base resin in the extruder to provide a toner comprising a pigment, optional charge additive and crosslinked resin comprising linear portions and crosslinked portions; and wherein said crosslinked portions are comprised of densely crosslinked microgel particles.

Abstract: A method is provided for controlling the dosage of a fluidized polymerizing catalyst into a polymerization reactor. The method comprises mixing a solid polymerization catalyst with wax and feeding the flowing catalyst-wax mixture through a pipe to the dosage pump. The inlet opening of the cylinder of the dosage pump is opened to draw catalyst-wax mixture through the inlet opening by means of the back motion of the piston. The inlet opening is then closed and the outlet opening is opened. Flowing catalyst-wax mixture is then pressed from the cylinder through the outlet opening by means of the back motion of the piston. The outlet opening is then closed. Opening and closing of the inlet and outlet openings is carried out by rotating an intermediate pipe arranged between the cylinder and piston so that a transmission opening in the intermediate pipe moves upon either the inlet or outlet opening. The intermediate pipe surface always covers at least one of the inlet or outlet openings.

Abstract: A process for producing a vinyl chloride-based polymer in which an aqueous suspension of a vinyl chloride-based monomeric material placed in a polymerization vessel equipped with an agitating element is subjected to suspension polymerization by introducing a polymerization initiator to the aqueous suspension at a position located inside the diameter of the agitating element being rotated. By this process it is possible to prevent totally the deposition of polymer scale on the inside wall of the polymerization vessel, particularly in the vicinity of a gas-liquid interface. Therefore, troubles arising from polymer scale formation and labor needed for removing such polymer scale are obviated, and a vinyl chloride-based polymer of high quality can be produced efficiently.

Abstract: Novel ethylene homopolymers and ethylene copolymers which are suitable for film production and have a density from 925 to 940 kg /m.sup.3, a melt flow index (MFI) of <1 g/10 min at 190.degree. C. and at an applied force of 2.16 kp can be prepared by free radical polymerization of the monomers at from 500 to 5000 bar and reaction temperatures T of from 40.degree. to 320.degree. C. by means of an initiator with virtually complete exclusion of oxygen in at least n=3 polymerization stages. In the first stage, the total amount or the predominant part of the monomers is subjected to the polymerization by means of part of the required initiator until the polymerization virtually comes to a stop. A further part of the initiator and, if required, of the monomers is then added to the mixture cooled to 20.degree.-60.degree. C. This process is repeated in the subsequent stages until the n th stage, at least the initiators used in the n th stage having a half-life temperature of from 90.degree. to 260.degree. C.

Abstract: The invention relates to copolymers containing carboxyl groups and having an acid number of 20 to 150 mg of KOH/g and a number average molecular weight of 2000 to 8000, which can preferably be prepared from copolymers containing hydroxyl groups by reaction with carboxylic anhydrides, to a process for their preparation and their use in coating agents. The copolymers contain a vinyl ester, a vinyl aromatic, a hydroxyalkyl ester of an .alpha.,.beta.-unsaturated carboxylic acid, and optionally other monomers that may contain acid groups.

Abstract: A process for controlling the continuous gas-phase polymerization of one or more alpha-olefins in a fluidized and/or mechanically stirred bed reactor using a high activity catalyst based on a transition metal of groups IV, V or VI of the Periodic Table comprises introducing into the reactor, continuously and simultaneously, an activity retarder and an activator, in very small amounts, in a molar ratio and at flow rates which are varied with time in order to maintain substantially constant either the polymerization rate or the transition metal content of the polymer produced.

Abstract: A process for emulsion polymerization to form a latex having a particle size greater than about 0.5 micrometers by charging to a reaction vessel under agitation a reaction mixture including water, emulsifiers at an initial concentration slightly greater than or equal to the critical micelle concentration, a protective colloid, ethylenically unsaturated monomers, and an ionically balanced combination of an anionic and a cationic water soluble free radical initiator or a nonionic initiator; reacting the mixture to form an emulsion of polymerized monomer; and adding additional monomer, emulsifier, and protective colloid and a water soluble chain transfer agent to the reactor while continuing to agitate the mixture under conditions such that the emulsifier concentration does not exceed that at which new polymeric nuclei are formed.

Abstract: A process for preparing a blend of a norbornene polymer and a vinyl polymer, the process comprising (a) injecting into a mold a reaction mixture comprising from about 30 to about 70 weight percent, based on the total monomer weight, of at least one substituted or unsubstituted norbornene monomer, from about 70 to about 30 weight percent of at least one polymerizable monomer, a metathesis catalyst system comprising a transition metal catalyst and a cocatalyst, and a free radical initiator, and (b) subjecting the reaction mixture to temperature conditions to sequentially initiate polymerization of the norbornene monomer and the vinyl monomer.

Abstract: Polyethylene and copolymers of predominant amounts of ethylene and minor amounts of comonomers which are polymerizable with ethylene are obtainable by free radical polymerization of the monomers under from 1,500 to 5,000 bar and at from 40.degree. to 250.degree. C. by means of an initiator with virtually complete exclusion of oxygen in not less than n=3 polymerization stages, by a method in which, in the first stage, the total amount of the predominant part of the monomers are subjected to polymerization using some of the initiator required, until said polymerization comes virtually to a stop, thereafter a further part of the initiator and, if required, of the monomers are added to the mixture, which has been cooled by 20.degree.-60.degree. C., and this process is repeated in the subsequent stages until the n th stage, with the proviso that the initiators used in the (n-1) th stage have a half-life temperature of from 80.degree. to 160.degree. C.

Abstract: A conjugated diene compound prepolymer solution useful for the production of a vinyl aromatic compound high impact polymer material is produced by a process in which a prepolymerization mixture is prepared from 1 to 70 parts by weight of a conjugated diene compound and 30 to 99 parts by weight of a vinyl aromatic compound, and is prepolymerized at 0.degree. C. to 150.degree. C. in the presence of a prepolymerization catalyst which can cause the conjugated diene compound to be selectively polymerized but is substantially not effective for the polymerization of the vinyl aromatic compound to an extent such that the conjugated diene compound and the vinyl aromatic compound are prepolymerized at degrees of conversion of the conjugated diene compound at least 50% and 10% or less, respectively, and the resultant prepolymer solution is further polymerized by a radical or anionic polymerization method so that the vinyl aromatic compound is polymerized with the conjugated diene compound prepolymer.

Abstract: A process for producing a styrene-based polymer having a high syndiotactic configuration, which comprises polymerizing a styrene-based monomer with addition of catalyst in such amounts that the conversion at 30 minutes after the polymerization starts becomes 2 to 50%, and then continuing the polymerization with additions of the catalyst when the conversion exceeds 10%.According to the process, the productivity can be improved while easily attaining safe running of the reactor and successful controlling of reaction heat.

Abstract: A process for preparing an ethylene polymer by a two-stage polymerization of ethylene or ethylene and an .alpha.-olefin in an inert hydrocarbon at 50.degree.-100.degree. C. using a coordination polymerization catalyst containing a solid component and an organoaluminum compound, said solid component containing a transition metal compound, which process comprises:(a) in a first stage, producing 10-90% by weight based on the total polymer quantity of a polymer having a melt index in the range of 0.0001 to 0.5 g/10 min as measured according to ASTM D 1238-73, Condition E, using as said solid component a solid product obtained by supporting chromium trioxide or a compound which on calcining forms chromium oxide at least partially, on an inorganic oxide carrier followed by calcining, and using as said organoaluminum compound a compound of the general formula ##STR1## wherein R is a hydrocarbon radical having 1 to 18 carbon atoms and n is 2.ltoreq.n.ltoreq.

Abstract: The processability of a polybutadiene with a high content of 1,4-cis-structure is improved by means of the addition of PCl.sub.3 before the polymerization reaction is quenched and when Mooney viscosity of polybutadiene has reached a prefixed value, preferably lower than, or equal to 30; the polymerization of butadiene is carried out in a solution in an aliphatic or cycloaliphatic solvent, in the presence of a catalytic system based on rare earths, preferably a neodymium-based catalytic system.

Abstract: Solutions of VCl.sub.4 in inert organic solvent are stabilized by incorporation of decomposition retardants being halogenated organic compounds having at least two halogen atoms attached to the same carbon atom and activated by adjacent electron donor groups or carbon-carbon double bonds. One of the especially preferred stabilizers is butyl perchlorocrotonate. The solutions are useful in polymerization processes.

Abstract: Metals from Groups I and II and organometallic compounds thereof can be used to catalyze the polymerization of diene monomers into polymers. The polymers formed in such polymerizations are terminated with the metal used to catalyze the polymerization and are sometimes referred to as living polymers. Very useful blends of such polymers can be made by utilizing the process of the present invention.

Abstract: Water-soluble polymers or copolymers of acrylic and/or methacrylic acid which contain at least 50 base mole percent of these acids and as end groups hydrogen atoms, hydroxyl groups and moieties of a water-soluble mercaptan or moieties with a sulfoxide group formed therefrom are produced in a readily reproducible manner and free of mercaptan odor in aqueous solution by polymerization with an initiator system consisting of hydrogen peroxide, a water-soluble mercaptan and an iron salt and used as calcium-binding additives or as dispersants in aqueous systems.

Abstract: An improved process is provided for preparing stable low viscosity polymer-polyols containing less than about 100 ppm residual monomers by using a monoperoxycarbonate initiator in combination with at least one initiator selected from diperoxyketals and peroxyesters, as chaser catalysts, at or near the end of the polymerization. The polymer-polyols prepared by the instant invention can be used to prepare high resiliency (load bearing) polyurethane foams.

Abstract: Copolymers of ethylene with vinyl esters are prepared in a continuously operated tubular polymerization system at high pressure and temperatures by feeding a mixture of ethylene, vinyl ester, initiator and, if appropriate, regulant into the polymerization system in the form of a mainstream at the inlet point thereof and at the same time through two or more secondary streams downstream of the inlet point, secondary streams (I) being metered in at points where the reaction temperature has just exceeded a maximum temperature due to the heat of polymerization and secondary streams (II) at points which, relative to the direction of flow of the ethylene, are upstream of the feed points of secondary streams (I) and upstream of the respective maximum temperature.

Abstract: A process is provided for the free radical polymerization of monomers derived from substituted or unsubstituted acrylic acid/methacrylic acid and esters thereof for the production of a polymer having a narrow molecular weight distribution and an average molecular weight of less than 4000. These polymers are produced by the solution polymerizing of said monomers wherein 20-40% by weight of the monomer composition is hydroxyalkyl acrylate or methacrylate in the presence of a solvent system suitable for high solids coating applications and in the presence of an initiating amount of a tertiary alkyl hydroperoxide and/or its derivatives having at least 5 carbons wherein the initiator and monomers, alone or in combination, are added continuously at a programmed rate wherein the rate of addition corresponds approximately to the rate of decomposition of said monomer and initiator. These polymers are used for high solids coating applications.

Abstract: Device and process for introducing a powder with catalytic activity into a fluidized bed polymerization reactor (1), the said device comprising:a storage enclosure (2) for powder with catalytic activity, provided with a feed line (3) for powder with catalytic activity and a shut-off valve (26), this enclosure being connected to a metering device (4) making it possible to deliver periodically a given volume of powder with catalytic activity,an intermediate chamber (5), placed below the metering device to receive direct the powder delivered by the latter, this intermediate chamber comprising in its upper part a tube (6) bringing in an inert carrier gas, provided with a shut-off valve,piping for conveying the powder (8) connecting the bottom part of the intermediate chamber to the fluidized-bed reactor, this piping having a portion which is more or less horizontal, the said powder conveying piping being provided with a full-bore rapid-opening valve (10).

Abstract: A bromate/bisulfite redox initiator system has been found useful for polymerizing tetrafluoroethylene to make resins of good stretch capability.

Abstract: Water-in-oil emulsions of monomers which form water-soluble polymers are polymerized in the presence of a biphase initiator system containing both an oil-soluble initiator and a water-soluble initiator or activator or alternatively a water-soluble initiator and an oil-soluble activator which results in polymers having improved performance characteristics. In addition, the system permits the satisfactory polymerization of monomers which could not have been reproducibly polymerized.

Abstract: An improved process is provided for producing porous PVC resin particles by a thickened aqueous suspension polymerization process comprising polymerizing vinyl chloride monomer in an aqueous suspension wherein said aqueous medium contains at least one dispersant capable of thickening water, and optionally at least one secondary surfactant, at least one oil-soluble free radical generating catalyst, the improvement comprising charging said free radical catalyst as a solution wherein the solvent for said catalyst solution has a density equal to or less than that of the monomer being polymerized and the catalyst solution has a density less than water.

Abstract: The present invention relates to the production of 1,4-cis-polybutadiene and of copolymers of butadiene with other conjugated diolefins, by means of the catalytic polymerization or copolymerization of monomer butadiene, by an either continuous or batch process, operating in the presence or in the absence of diluents, and carrying out a portionwise addition, during the polymerization, of a portion of the organometallic compound of aluminum (or of the related hydride derivative), constituiting also one of catalytic components.

Abstract: Device and process for introducing a powder with catalytic activity into a fluidized bed polymerization reactor (1), the said device comprising:a storage enclosure (2) for powder with catalytic activity, provided with a feed line (3) for powder with catalytic activity and a shut-off valve (26), this enclosure being connected to a metering device (4) making it possible to deliver periodically a given volume of powder with catalytic activity,an intermediate chamber (5), placed below the metering device to receive direct the powder delivered by the latter, this intermediate chamber comprising in its upper part a tube (6) bringing in a inert carrier gas, provided with a shut-off valve,piping for conveying the powder (8) connecting the bottom part of the intermediate chamber to the fluidized-bed reactor, this piping having a portion which is more or less horizontal, the said powder conveying piping being provided with a full-bore rapid-opening valve (10).

Abstract: A new class of hydrocarbon foaming agents which are block copolymers, one block of which is a styrene derivative, the other a vinylsilane derivative. Said hydrocarbon foaming agents are nonreactive with common anionic initiators.

Abstract: An improved process is provided for producing porous PVC resin particles by a thickened aqueous suspension polymerization process comprising polymerizing vinyl chloride monomer in an aqueous suspension wherein said aqueous medium contains at least one dispersant capable of thickening water, and optionally at least one secondary surfactant, at least one oil-soluble free radical generating catalyst, the improvement comprising charging said free radical catalyst as a solution wherein the solvent for said catalyst solution has a density equal to or less than that of the monomer being polymerized and the catalyst solution has a density less than water.

Abstract: In a gas-phase fluidized-bed polyethylene reactor using a Ziegler catalyst under operating conditions, a co-catalyst, such as triethyl aluminum, is added to the reactor by mixing the TEA with some of the feed ethylene and pumping the solution into the reactor.

Abstract: Process of polymerizing a monomer charge including ethylene by (1) drying an inorganic oxide having surface hydroxyl groups to form a support that is substantially free of adsorbed water, (2) reacting the surface hydroxyl groups of the support with at least a substantially stoichiometric amount of at least one organometallic compound corresponding to the formula R.sub.x MR'.sub.y R".sub.z, wherein M is a metal of Group III of the periodic table, R is an alkyl group containing 1 to 12 carbon atoms, R' and R" are independently selected from the group consisting of H, Cl, and alkyl and alkoxy groups containing 1 to 12 carbon atoms, x has a value of 1 to 3, and y and z both represent values of 0 to 2, the sum of which is not greater than 3-x, (3) reacting the thus-treated support with at least about 0.001 mol, per mol of organometallic compound, of at least one vanadium compound prepared by reacting one molar proportion of VOCl.sub.3 and/or VOBr.sub.3 with about 0.

Abstract: Process of polymerizing a monomer charge including ethylene by (1) drying an inorganic oxide having surface hydroxyl groups, e.g. silica, alumina, magnesia, etc. to remove adsorbed water (2) reacting the surface hydroxyl groups with at least a stoichiometric amount of an organometallic compound having at least one alkyl group attached to a Group III metal, e.g., a trialkylaluminum, (3) reacting the thus-treated inorganic oxide with a vanadium halide, such as (a) VOCl.sub.3, VOBr.sub.3, and/or mono-, di-, and/or trihydrocarbyloxy derivatives thereof and/or (b) VCl.sub.4, VBr.sub.4, and/or mono-, di-, tri-, and/or tetrahydrocarbyloxy derivatives thereof, (4) reacting that reaction product with at least about 0.1 mol, per mol of organometallic compound, of an ether-alcohol corresponding to the formula R"[OCHR'(CH.sub.2).sub.n CHR].sub.

Abstract: Process of polymerizing a monomer charge including ethylene by (1) drying an inorganic oxide having surface hydroxyl groups to form a support that is substantially free of adsorbed water, (2) reacting the surface hydroxyl groups of the support with at least about 0.5 mol, per mol of surface hydroxyl groups, of at least one organometallic compound corresponding to the formula R.sub.x MR'.sub.y R".sub.z, wherein M is a metal of Group III of the periodic table, R is an alkyl group containing 1 to 12 carbon atoms, R' and R" are independently selected from the group consisting of H, Cl, and alkyl and alkoxy groups containing 1 to 12 carbon atoms, x has a value of 1 to 3, and y and z both represent values of 0 to 2, the sum of which is not greater than 3-x, (3) reacting the thus-treated support with at least about 0.001 molar proportion, per mol of organometallic compound, of a vanadium component consisting essentially of a mixture of about 10-90 mol percent of VOCl.sub.

Abstract: Process of polymerizing a monomer charge including ethylene by (1) drying an inorganic oxide having surface hydroxyl groups to form a support that is substantially free of adsorbed water, (2) reacting the surface hydroxyl groups of the support with at least a substantially stoichiometric amount of at least one organometallic compound corresponding to the formula R.sub.x MR'.sub.y R".sub.z, wherein M is a metal of Group III of the periodic table, R is an alkyl group containing 1 to 12 carbon atoms, R' and R" are independently selected from the group consisting of H, Cl, and alkyl and alkoxy groups containing 1 to 12 carbon atoms, x has a value of 1 to 3, and y and z both represent values of 0 to 2, the sum of which is not greater than 3-x, (3) reacting the thus-treated support with at least about 0.001 mol, per mol of organometallic compound, of at least one vanadium compound corresponding to a formula selected from (RO).sub.n VOX.sub.3-n and (RO).sub.m VX.sub.4-m, in which formulas R represents a C.sub.1 -C.

Abstract: A desired unreacted monomer concentration is maintained in the reaction effluent removed from a polymerization reactor by manipulating the catalyst feed rate to the polymerization reactor.

Abstract: A diene rubber composition comprising 25 to 90 parts by weight of at least one high molecular weight diene rubber (A) having an intrinsic viscosity [.eta.] of at least 2.0 and a glass transition point of not lower than -50.degree. C. and 75 to 10 parts by weight of at least one low molecular weight diene rubber (B) having an intrinsic viscosity [.eta.] of 0.01 to 2.0, said composition having an average intrinsic viscosity of at least 1.8.Since this composition has an excellent wet grip and rolling resistance property and moreover has excellent processability, it is employed as tire tread rubber.

Abstract: Process for preparing copolymers of vinyl-aromatic monomers with ethylenically unsaturated nitriles having a very low content of unreacted residual monomers, consisting in adding to the polymerization dispersion, containing a compound capable of giving free radicals, and in the final step of the polymerization process, from 0.2 to 2% by weight of a comonomer which is reactive towards the unreacted monomers.

Abstract: There is provided a method for the suspension polymerization of one or more styrenic monomers. This method involves increasing the amount of substantially water insoluble free radical initiator in the suspension after the conversion of the monomer has reached at least 50%. The temperature of the suspension is at least 110.degree. C. throughout the entire polymerization.

Abstract: A process of preparing a bimodal or multimodal homopolymer of a conjugated diene or a bimodal or multimodal copolymer of a conjugated diene with another conjugated diene or with a vinyl aromatic compound consists in polymerizing the monomer(s) in a reaction medium at a temperature of between 20.degree. C. and 200.degree. C. in the presence of a catalytic system comprising an organolithium initiator, a barium, strontium or calcium compound, and an organometallic compound of a metal of group 2B or 3A of the periodic classification of elements of the Mendeleev Table and adding hydrogen as a modifying agent to the reaction medium during the course of the polymerization reaction.

Abstract: Polytetrafluoroethylene dispersions obtained from dispersion polymerization which have high solids content and small polytetrafluoroethylene particles are obtained by employing a combination of disuccinic acid peroxide and an inorganic persulfate, and a combination of an anionic and a hydrocarbon dispersing agent, precharged to the polymerization mixture, and by adding a combination of disuccinic acid peroxide and an anionic dispersing agent during the course of the polymerization.

Abstract: A process of preparing a bimodal or multimodal homopolymer of a conjugated diene or a bimodal or multimodal copolymer of a conjugated diene with another conjugated diene or with a vinyl aromatic compound consists in polymerizing the monomer(s) in a reaction medium at a temperature of between 20.degree. C. and 200.degree. C. in the presence of a catalyst system comprising an organolithium initiator, a barium, strontium or calcium compound, and an organometallic compound of a metal of group 2B or 3A of the periodic classification of elements of the Mendeleev Table, and adding to the reaction medium during the course of the polymerization reaction a compound of a transition metal of groups 1B to 7B and 8 or a magnesium compound of the general formula Mg(A).sub.2.

Abstract: A process for reducing the residual monomer level of a polymer latex prepared by emulsion polymerization comprises exposing the latex in a separate vessel from that in which the main polymerization has been carried out to conditions under which free radicals are produced by a secondary catalyst added to the latex, the said catalyst being oil soluble or having an oil soluble component. In a preferred embodiment a polymer latex prepared by the emulsion polymerization of styrene alone or a mixture containing styrene having a residual styrene level not exceeding 0.1% based on latex volume may be obtained.

Abstract: The present invention involves compositions of super absorbent polymers which absorb many times their weight in water and aqueous fluids. Super absorbent polymers in the prior art have effectively absorbed many times their weight of water, however, they become slimy to the touch or become so fluid as to migrate away from their point of application.The absorbent composition of the current invention absorbs substantial amounts of water without becoming slimy and migrating out from its applicator, as in absorbent articles. The absorbent composition of the current invention comprises a copolymer of acrylic acid cross-linked with a first cross-linking component comprising a monomer having at least two vinyl groups and a second cross-linking component comprising an ionic divalent cation. In the current invention, this composition can be mixed with cellulose fibers to enhance wicking.

Abstract: A process for controlling polymer particle size distribution in the vapor phase polymerization of olefins comprises contacting fresh catalyst with a stream of wetting liquid before the catalyst is dispersed in the polymer bed, said wetting liquid being introduced at a wetting liquid flux density greater than about 20.

Abstract: There is disclosed a process for the aqueous polymerization of acrylamide to produce polymers of high molecular weight utilizing mixtures of water and monomer, at least one of which can be contaminated with small amounts of polymerization inhibiting components. In the process of the invention, a minimum amount of a redox pair catalyst is utilized in order to obtain the desired high molecular weight polymer. The minimum amount of catalyst is automatically provided to the polymerization mixture by adding a first member of a redox pair to the polymerization mixture and intimately combining a second member of the redox pair catalyst with an organic polymer capable of forming a colloidal dispersion in an aqueous medium and adding this intimate mixture to the mixture of water, acrylamide monomer, and a first member of the redox pair catalyst.