Abstract: This invention relates flame retardant compositions containing low molecular weight brominated anionic, chain transfer, vinyl aromatic polymers, hereinafter “ACTVAP”. The compositions can accommodate high bromine content while still exhibiting a low thermally labile bromine content. The compositions have glass transition temperatures, Tg, that are predictive of acceptable melt flows and heat distortion temperatures (HDT) in HIPS and ABS based formulations substrates. The compositions, are suitable flame retardant candidates for use in thermoplastic formulations, e.g. polystyrene and ABS formulations.

Abstract: A method for producing polymer particles includes a preparation step for preparing a first oily liquid containing an oily olefin monomer, a radical polymerization initiator, and an iodine molecule, a synthesis step for obtaining a second oily liquid containing at least an iodine compound produced by a reaction between a radical generated by cleavage of the radical polymerization initiator and the iodine molecule in the first oily liquid, a suspension step for obtaining an oil droplet of the second oily liquid by suspending the second oily liquid in water, and a polymerization step for polymerizing the oily olefin monomer in the oil droplet.

Abstract: The present invention relates to a process for the preparation of water-absorbing polymer structures, comprising the following process steps: I) providing an untreated, water-absorbing polymer structure; and II) bringing the untreated, water-absorbing polymer structure into contact with a salt comprising a divalent or higher-valent cation of a metal and at least one organic base as anion. The invention relates also to the water-absorbing polymer structures obtainable by that process, to water-absorbing polymer structures, to a composite comprising a water-absorbing polymer structure and a substrate, to a process for the preparation of a composite, to the composite obtainable by that process, to chemical products, such as foams, molded articles and fibers comprising water-absorbing polymer structures or a composite, to the use of water-absorbing polymer structures or of a composite in chemical products and to the use of a salt in the treatment of the surface of water-absorbing polymer structures.

Abstract: Bromination of styrenic polymer is carried out in a closed reaction system to retain HX coproduct (where HX is HBr or HCl, or both) in the bromination reaction mixture at superatmospheric pressure. Preferably, the reaction mixture which includes the brominated styrenic polymer and substantially all of the HX coproduct formed is discharged into an aqueous quenching medium. By operating in this manner, the reaction is terminated and the brominated styrenic polymer of desired bromine content and substantially all HX coproduct are captured in the same operation, process equipment costs are reduced, and processing of the reaction mixture is facilitated.

Abstract: According to the present invention, during or after the process of separating an aqueous solution of hydrochloric acid by-produced from a chlorinated vinyl chloride resin slurry obtained by chlorinating vinyl chloride resin or a copolymer of vinyl chloride and another copolymerizable monomer, hypochlorite is added to the chlorinated vinyl chloride slurry or water-containing resin. Due to this, the concentration of hydrochloric acid in the chlorinated vinyl chloride resin or chlorinated vinyl chloride copolymer resin before drying is reduced, and the problem of removing hydrochloric acid in the subsequent drying treatment is reduced, whereby the problem of corrosion of a drier can be reduced.

Abstract: The invention relates to crosslinked polymerizates which are capable of absorbing, which are based on partially neutralized, monoethylenically unsaturated monomers that carry acidic groups, which exhibit improved properties, in particular, with regard to their ability to transport liquids when in a swollen state, and which have been subsequently crosslinked on the surface thereof with a combination consisting of an organic crosslinker compound, with the exception of polyols, and of a cation provided in the form of a salt in an aqueous solution.

Abstract: A composition and the method for sustaining the biocidal activity of chlorinated polystyrene hydantoin beads. The method comprises supplying a continuous low level halogen concentration to the chlorinated polystyrene hydantoin beads in the water to be treated that flows in contact with the chlorinated polystyrene hydantoin beads, resulting in treated water suitable for drinking.

Abstract: The present invention relates to powdered, crosslinked polymer compositions, containing a) 55-99.9 wt.-% of at least one polymerized, ethylenically unsaturated, polymerizable monomer which contains acid groups neutralized to at least 25 mole-%, b) 0-40 wt.-% of polymerized, unsaturated monomers copolymerizable with a), c) 0.01-5.0 wt.-%, preferably 0.1-2.0 wt.-% of one or more crosslinking agents, d) 0-30 wt.-% of a water-soluble polymer, the weight amounts a) through d) being based on anhydrous polymer composition, and the sum of these components always being 100 wt.-%, which compositions can be obtained by continuous polymerization wherein at least one parameter biasing the polymerization is varied according to a recurring pattern. The present invention also relates to a process for their production and to their use.

Abstract: A process for making poly(hydroxystyrene)s whose phenolic hydroxyl groups are partially protected by acid-decomposable or -eliminable groups, by which the degree of deblocking of the phenolic hydroxyl groups is controlled. Namely, the production of a polymer containing, in the molecule, repeating units of the general formula (IA) and those of the general formula (IB), comprising adding an acid to polymer (B) containing in the molecule repeating units of general formula (II) in an organic solvent with the molar ratio of the acid to the OR3 group being 0.0001 equivalent or above but below 0.05 equivalent, and reacting the polymer with the acid. In the general formulae, R1 is hydrogen or methyl; R2 is C1-6 alkyl; R3 is an acid-decomposable or -eliminable group; R4 is hydrogen or a group derived from R3 by decomposition with acid; and p is 0, 1, or 2, with the proviso that the IB/IA molar ratio ranges 98/2 to 30/70.

Abstract: A method of fluorinating a substance comprises providing a reaction mixture comprising a liquid or supercritical carbon dioxide reaction medium, a first reactant, and a second reactant, wherein the first reactant is a fluorinating reagent, and then contacting the first reactant and the second reactant in the carbon dioxide such that the first reactant fluorinates the second reactant.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, the floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.

Abstract: A polyvinyl chloride resin having an average particle diameter of not less than 150 &mgr;m and porosity at 31-1,011 psi of not less than 0.15 cc/g is suspended in an aqueous medium and chlorinated by blowing gaseous chlorine into the aqueous suspension. In this way, floating resin formation during chlorination can be prevented and a chlorinated polyvinyl chloride resin excellent in free flow property and showing good resistance to initial discoloration and good thermal stability in heating and molding processes can be produced.

Abstract: In producing chlorinated polyvinyl chloride resin having chlorination degree of 60-73% by weight, wherein polyvinyl chloride resin is suspended in an aqueous medium and chlorine gas is blown into said suspension under beam of a mercury lamp in the temperature range of 40-90° C., an organic peroxide compound having a 10 hour half-life in the range of 40-90° C. is added into the reaction vessel in the ratio of 0.01-1 parts to 100 parts of the polyvinyl chloride resin by weight before the chlorination reaction is started. By this method, the time for chlorination reaction can be shortened without sacrificing the initial coloring and the heat stability, whereby chlorinated polyvinyl chloride can be produced with significantly improved productivity.

Abstract: C.sub.4 -C.sub.16 alkyl rubbers are brominated by reacting the alkyl rubbers with bromine in the presence of organic azo compounds and/or alkali metal and/or alkaline earth metal hypochlorites and in the presence of linear, branched and/or cyclic alkanes and water at temperatures of 10.degree. to 100.degree. C., optionally under pressure, wherein the quantity of bromine is 0.2 to 1.2 times the molar quantity of double bonds contained in the rubber, 0.1 to 3 times the molar quantity of hypochlorite and/or azo compounds is used relative to the quantity of bromine used, providing that the concentration of the hypochlorites in an aqueous solution is 2 to 20 wt. %, and wherein 5 to 20 wt. % of water, 60 to 90 wt. % of alkanes and 5 to 25 wt. % of alkyl rubber are used relative to 100 wt. % of the total of alkyl rubber, alkanes and water.

Abstract: A chlorinated ethylene-propylene copolymer having a chlorine content of 20 to 45% by weight and a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 10 to 150 is produced by chlorinating in two or three stages, by contact with chlorine gas in an aqueous suspension, an ethylene-propylene copolymer having a propylene content of 15 to 40% by weight, a melt flow index of 0.01 to 5.0 g/10 minutes, a melting peak as measured by differential scan calorimeter (DSC) of 80.degree. C. or more, a crystallinity as measured by X-rays of 3% or more, an index M.sub.W /M.sub.N of the distribution of molecular wieght, determined by gel permeation chromatography (GPC), of greater than 4, and a Mooney visocisty (ML.sub.1+4, 100.degree. C.) of 10 to 180.

Abstract: A process for preparing linear block and three arm star block copolymers having blocks of polyisobutylene and blocks of anionically polymerizable monomers comprises mixing a first solution of a polyisobutylene having a number average molecular weight of from about 4,000 to about 60,000 and having from 1 to 3 terminal allylic halogens with a second solution of a living alkali metal terminated polymer having a number average molecular weight of from about 4,000 to about 60,000 in relative proportions at a temperature of from about 10.degree. C. to about 80.degree. C. for a period of time of from about 30 minutes to about 24 hours whereby a significant amount of linear block or three arm star block copolymer is formed. A polyisobutylene having from 1 to 3 terminal allylic halogens is provided and a process for preparing said polyisobutylene.

Abstract: N-vinylformamide is polymerized with or without other water-soluble monoethylenically unsaturated monomers and with or without water-insoluble monoethylenically unsaturated monomers in not less than 30% strength by weight aqueous monomer solutions in the presence of a polymerization initiator at not more than 150.degree. C. in a kneader by a method in which the polymerization is carried out to such an extent that the initially formed water-containing polymer gel disintegrates into fine particles and the finely divided polymer obtainable in this manner is hydrolyzed, preferably in the kneader, so that not less than 0.1 mol % of the N-vinylformamide units present in the polymer are converted into vinylamine units. The polymers obtainable in this manner dissolve readily in water. The aqueous solutions are used, for example, in papermaking and tertiary oil production.

Abstract: A process for halogenating star-branched butyl rubber is provided wherein water and a wetting agent or wetting agent precursor are added to a solution comprising the star-branched butyl rubber, solid particles of branching agent and an organic solvent prior to the neutralization step to increase the rate of neutralization of the hydrogen halide by-product of the halogenation reaction.

Abstract: A method of producing solvent-soluble chlorinated polyolefin as resin for paint, ink, adhesion and film-forming uses comprising suspending polyolefin powder finely pulverized to a specific surface area of 300 to 20,000 cm.sup.2 /g into aqueous medium and conducting chlorination.

Abstract: A method of producing organic solvent-soluble chlorinated rubber is disclosed, which is characterized in that, in the method of chlorinating rubber latex with chlorine gas up to 60 to 75% chlorine content in the aqueous medium as it is,(A) nonionic or cationic surfactant is added to rubber latex prior to chlorination and then acid is added to perform the acidifying treatment of latex,(B) rubber latex is chlorinated up to at least not less than 30% chlorine content at a temperature of not higher than 50.degree. C. blocking off the light in the first step of chlorination, and(C) remaining chlorination is performed while irradiating ultraviolet rays in the second step of chlorination. The chlorinated product is also claimed.

Abstract: A chlorinated ethylene-propylene copolymer having a chlorine content of 20 to 45% by weight and a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 10 to 150 is produced by chlorinating in two or three stages, by contact with chlorine gas in an aqueous suspension, an ethylene-propylene copolymer having a propylene content of 15 to 40% by weight, a melt flow index of 0.01 to 5.0 g/10 minutes, a melting peak as measured by differential scan calorimeter (DSC) of 80.degree. C. or more, a crystallinity as measured by X-rays of 3% or more, an index M.sub.W /M.sub.N of the distribution of molecular weight, determined by gel permeation chromatography (GPC), of greater than 4, and a Mooney visocisty (ML.sub.1+4, 100.degree. C.) of 10 to 180.

Abstract: A halogenation process is provided for halogenating a polymer, in which process the halogenation reaction product is neutralized by reaction of an aqueous alkaline material in the presence of a critical limited amount of alcohol to increase the neutralization rate.

Abstract: A composite comprises a coating which is adhered to a highly saturated elastomer having a corona discharge activated surface which is chemically fixed by a halogenating agent. A coating such as a paint, a weather-resistant film, etc., or an adhesive layer, is adhered to the activated and fixed surface. Various halogenating agents include N-halohydantoins, N-haloimides, N-haloamides, aqueous chlorine or bromine solutions, and acidified hypochlorite solutions. The composite is useful for EPDM roofing and consumer goods, e.g., a flexible polyurethane paint applied to the sidewalls of tires, as a decorated article, bonded composites, and the like.

Abstract: It has been found that the properties of polycyclic cycloolefins, in particular poly(dicyclopentadiene), can be substantially improved by halogenation of the surface. Both aqueous and gaseous treatments of the polymer have been found to significantly improve the resistance to various acids and solvents. Chlorine, fluorine and bromine, in particular, when incorporated into the surface of the polymer increase chemical resistance, improve retention of properties upon aging, reduce emission of residual monomer, and encourage better adhesion of paint.Among the substances found to provide the desired chemical resistance on the polymer surface were dry chlorine gas, aqueous chlorine, immersion in liquid bromine, aqueous bromine, and fluorine gas. Similar improvement in chemical resistance can be obtained through treatment with pseudohalogen compounds or interhalogen compounds.

Abstract: A process for the rapid bulk polymerization of polybutadiene/nylon-6 block copolymers comprises the steps of preparing a mixture comprising from about 100 to about 50 parts by weight of a low molecular weight polybutadiene terminated by an isocyanate or isothiocyanate and end-capped with caprolactam providing a stable imide type terminated polymer, with from about 0 to about 50 parts by weight of a dry non-cold flowing rubber neutralized with caprolactam, charging the polymer mixture without hydrolyzing the end-capped polybutadiene to a reaction vessel with caprolactam and polymerizing the caprolactam at a temperature sufficient to flash off any solvents introduced during the step of preparing to form a block copolymer with the end-capped polybutadiene.

Abstract: The invention provides finely dispersed, agglomeration-free chloropolyethylene having good rubber and anti-blocking properties. The invention provides furthermore a process for the manufacture of such a chloropolyethylene, according to which chlorination of the starting polyethylene is carried out in the presence of a dispersing agent system of poly-N-vinylprrolidone and hydrophobic silicic acid. This process allows also the use of polyethylene types having a pronounced tendency to agglomeration.

Abstract: An after-chlorinated ethylene/butene-1 copolymer useful as a rubber material having especially good cold resistance characterized by having(a) 1 to 2 methyl groups per 100 carbon atoms,(b) a chlorine content of 25 to 35% by weight,(c) a weight average molecular weight of not less than 100,000,(d) a heat of fusion, determined by differential scanning calorimetry, of not more than 0.5 cal/g, and(e) an ethylene content of 93 to 97% by weight and a butene-1 content of 7 to 3% by weight.A process for its production is also provided.

Abstract: Method for the fluorination of a surface layer of articles molded from plastic, vulcanized rubber or other such macromolecular substances by the exposure of at least a part of the article's surface to a fluorine-yielding liquid in a controllable reaction, the liquid consisting of a solvent or solvent mixture containing dissolved elemental fluorine. Suitable solvents are especially halogen hydrocarbons in accordance with DIN 8962, which are liquid within a temperature range from -30.degree. C. to +10.degree. C., but also water and solvents having perfluoroalkyl groups. The liquid, in which a fluorine concentration between 0.5.times.10.sup.-3 and 1.times.10.sup.-2 mol/l is established by the introduction of fluorine diluted with inert gas, is used to treat the articles for about 20 seconds to 30 minutes; the fluorine can be activated if desired. The liquid can additionally contain sulfur dioxide, oxygen, carbon monoxide, chlorine, bromine, or mixtures thereof.

Abstract: The present invention pertains to the chlorination of polyvinyl chloride resin particles by exposing said particles of polyvinyl chloride particles while associated with chlorine to high-intensity pulsating actinic radiation.

Abstract: The disclosure relates to a process for making fine particulate, non-agglomerating chloropolyethylene by subjecting pulverulent polyethylene to a chlorination reaction in aqueous or aqueous/hydrochloric acid-suspension with chlorine gas at a temperature of about 20.degree. to 140.degree. C. in the presence of silicic acid and silicon oil, separating, washing and drying the chloropolyethylene. More particularly, the disclosure provides for the chlorination to be terminated and for the aqueous hydrochloric acid-suspension of chloropolyethylene to be then intensively mixed with an aqueous or aqueous/hydrochloric acid-dispersion having talc as well as an orthophosphoric acid mono- and/or diester or a polysiloxane by means of an emulsifier dispersed in it, and for the chloropolyethylene to be separated from the mixture, to be washed and dried.

Abstract: A process is disclosed which permits the photochlorination of poly(vinyl chloride) resin ("PVC"), in an aqueous medium without the use of swelling agents such as are conventionally used. The chlorination reaction proceeds in an aqueous suspension having a high PVC concentration, yet allows the production of essentially uniformly chlorinated poly(vinyl chloride) resin ("CPVC") of excellent quality and uniformity, with a heat distortion temperature ("HDT") of at least 100.degree. C. The transfer of chlorine from the gaseous phase into the aqueous phase, and then into the solid PVC phase, has been accelerated by this process which provides a critical combination of photo-illumination, elevated temperature and elevated pressure in a reactor devoid of oxygen and a swelling agent for the PVC. The "water-chlorination process" of this invention provides a "soak" period, after removal of oxygen from the aqueous PVC suspension, at a soak temperature of about 60.degree. C. to about 75.degree. C.

Abstract: A simple and practical method for making post-chlorinated polymers based upon vinyl chloride is provided based upon conducting the chlorination reaction on a granular polymer suspended in aqueous hydrochloric acid in the presence of a stoichiometric excess of liquid chlorine and in the absence of any significant amount or organic solvent/swelling agent. Use of photo-radiation techniques is also avoided since the reaction is activated by means of a minor fraction of a percent based upon weight of said polymer of an organic peroxy compound which decomposes to form free radicals at the temperatures involved in the reaction.

Abstract: A process is disclosed for the preparation of chlorinated poly(vinyl chloride), (hereinafter "CPVC" for brevity), in the form of free-flowing macrogranules which are derived from solid free-flowing macrogranules of poly(vinyl chloride), (hereinafter "PVC" for brevity), by causing from about 0.6 to about 3.0 parts by weight (wt) of liquid chlorine which are absorbed perunit wt of solid PVC macrogranules to react with the PVC, without shedding reacted material from the macrogranules. The macrogranules of PVC containing absorbed liquid chlorine held therewithin, are maintained in a wetted but free-flowing, apparently dry reaction mass (due to which the process is referred to as "the relatively dry chlorination" or "the low liquid chlorine" process), in a reaction zone maintained at a temperature in the range from about -50.degree. C. to about 50.degree. C., and a pressure sufficient to maintain the chlorine in its liquid state.

Abstract: Salts of formamidines with polymers containing sulfonic acid groups; processes for producing these salts; and the use thereof in combating pests.

Abstract: Polyfunctional N-chloramide derivatives of homo-or copolymers of acrylamide or methacrylamide. These may be copolymers of methacrylamide and acrylamide; or of either of these with any of styrene, methylstyrene, dimethylstyrene, chlorostyrene and alkylacrylate. Preferred alkylacrylate include methyl-, methylmeth-, ethyl-, ethylmethyl-, butylmeth-, hexyl-, hexylmeth-, decyl-, decylmeth-, dodecyl- and dodecylmeth- species. The derivatives may be cross-linked by divinylbenzene or divinylether.

Abstract: A process is disclosed for making polyfunctional N-chloramide derivatives of homo--or copolymers of acrylamide or metharylamide wherein a homo--or copolymer of acrylamide or methacrylamide is chlorinated by means of chloride in a dilute aqueous suspension of a mineral acid at a temperature of 0.degree. to 40.degree. C.

Abstract: This invention relates to a polyfunctional isocyanate which is an acrylamide or methacrylamide homopolymer or interpolymer having 20 to 100% of its secondary .alpha. and tertiary .alpha. carbon atom amide groups converted to isocyanate groups, said polyfunctional isocyanate being free of alkali and urea groups.The polyfunctional isocyanates are prepared by reacting the N-chloramide derivative of the acrylamide or methacrylamide polymer, in an inert solvent, with a tertiary amine having a pK.sub.a value of more than 7.The polyfunctional isocyanates are useful for forming coating compositions.

Abstract: Surfaces of articles formed from (1) normally solid polymers of aliphatic mono-1-olefins and (2) elastomeric and resinous polymers of conjugated dienes and vinyl-substituted aromatic compounds are conditioned by contact with a fluorine-containing gas under conditions and for a period of time sufficient to render the surface receptive to adhesives, coatings, paints, inks, decorations, and the like. The fluorine-containing gas can be pure or admixed with up to about 99 volume percent inert gas.

Abstract: A process for preparing a fluorine-containing polymer having carboxyl groups, which comprises subjecting a fluorine-containing polymer having sulfonyl halide groups bonded to it to an oxidation reaction at a temperature of not more than 250.degree. C.; and a process for electrolysis, using as a diaphragm a member of the polymer obtained by the above process.

Abstract: A solution of butyl rubber in an inert solution such as n-hexane is halogenated in a continuous process using bromine chloride vapor and high intensity mixing means for both the halogenation and subsequent neutralization steps. Adjustment of the mole ratio of bromine chloride to isoprene, where an isobutylene-isoprene butyl copolymer is used, to less than about 1.5 to 1 prevents overhalogenation and significant molecular weight loss, while the use of bromine chloride vapor results in improved process safety.The doubly halogenated product, containing both bromine and chlorine in its structure can be vulcanized in the absence of sulfur, e.g., with zinc oxide. It is particularly useful in rubber compositions where the singly halogenated product is employed, but demonstrates product performance advantages compared to both brominated butyl rubber and chlorinated butyl rubber.

Abstract: When an elastomeric copolymer of a C.sub.4 or C.sub.5 conjugated diene and an aromatic vinyl compound is brominated in latex while keeping the uniformity of the latex until the amount of bormine combined with the copolymer reaches 0.5-15% by weight, the resulting brominated conjugated diene-aromatic vinyl compound rubber contains 3-80% by weight of a toluene-insoluble fraction formed by the bromination and has a high green strength and a good processability. A vulcanized rubber obtained from said brominated rubber has a high modulus of elasticity and a high tensile strength. When an anionic surfactant is used as an emulsifier, the uniformity of the above-mentioned latex can be kept by adjusting the pH value of the bromination reaction system to 9 or highter, preferably 10 or higher, during the reaction or by auxiliarily adding a nonionic surfactant. When a cationic or nonionic surfactant is used as an emulsifier, regulation of pH is unnecessary.

Abstract: A process is described for the preparation of a polymer having a recurring unit of the formula: ##STR1## where R is hydrogen or methyl, C.sub.n H.sub.2n is lower-alkylene, R.sub.1 and R.sub.2 are aryl or lower-alkyl, and x is 0 or 1. A polymer having a recurring unit of the formula: ##STR2## where X is chloro, bromo, iodo, chloroalkyl, bromoalkyl or iodoalkyl, is reacted with the appropriate aryl or alkyl chloride or bromide and arsenic trichloride, arsenic tribromide or arsenic trioxide in the presence of sodium, magnesium, or lithium metal. The resulting polymer is an intermediate in the preparation, by oxidation, of the corresponding As-oxide which polymer is useful as a catalyst for the conversion of isocyanates to the corresponding carbodiimides.

Abstract: A process is described for the preparation of a polymer having a recurring unit of the formula: ##STR1## where R is hydrogen or methyl, C.sub.n H.sub.2n is lower-alkylene, R.sub.1 and R.sub.2 are aryl and x is 0 or 1. A polymer having a recurring unit of the formula: ##STR2## where X is chloro, bromo, iodo, chloroalkyl, bromoalkyl or iodoalkyl, is reacted with a triarylarsine in the presence of lithium or sodium-potassium alloy. The resulting polymer is an intermediate in the preparation, by oxidation, of the corresponding As-oxide. The latter is useful as a catalyst for the conversion of isocyanates to the corresponding carbodiimides.

Abstract: A process for the preparation of chlorinated aliphatic polymers wherein chlorine-free polymers are chlorinated by using gaseous chlorine in chlorinated hydrocarbons as solvents and the chlorinated aliphatic polymers are recovered from the chlorinating solution by steam distillation in which process from 15 to 50% by weight of a lacquer resin is added to the chlorinating solution before steam distillation. The chlorinated polymers contain less residual solvent.

Abstract: In a process for the manufacture of a heat-stable, nuclear-brominated polystyrene by brominating, at -20.degree. C. to +40.degree. C., a polystyrene dissolved in a chlorinated hydrocarbon in the presence of a Lewis acid catalyst, an improvement is provided wherein the catalyst further comprises 0.02 to 2 moles, per mole of Lewis acid, of a nucleophilic substance which acts as a Lewis base for the Lewis acid.

Abstract: A process for the preparation of PVP-iodine by reacting polyvinylpyrrolidone powder with elementary iodine at from 70.degree. to 100.degree. C. The reaction is carried out in the presence of formic acid, oxalic acid or an ammonium salt or amide of carbonic acid, formic acid or oxalic acid. The process avoids the disadvantage of long periods of heating, which can result in degradation of the polyvinylpyrrolidone, and is particularly suitable for the preparation of a stable PVP-iodine using a low molecular weight polyvinylpyrrolidone.

Abstract: An improved process for chlorinating high density polyethylene "in bulk" is described, with a two-stage reaction, the first at temperatures below the crystalline melting point, and the second above that temperature, and using a polyethylene starting material having a critical combination of characteristics, as described.