Abstract: As the sealant material composition forming a sealant layer of a pneumatic tire provided with the sealant layer on a tire inner surface, the sealant material composition prepared by blending from 0.1 parts by mass to 20 parts by mass of a crosslinking agent, from 0.1 parts by mass to 40 parts by mass of an organic peroxide, and from 10 parts by mass to 400 parts by mass of a liquid polymer per 100 parts by mass of a butyl rubber is used.

Abstract: A method for producing chlorinated polyvinyl chloride includes bringing chlorine gas into contact with a mixture comprising a polyvinyl chloride powder and at least one inorganic filler; and irradiating the mixture with UV light to perform a chlorination reaction. At least one inorganic filler is selected from the group consisting of silica, carbon black, and talc.

Abstract: The invention relates to an energy efficient, environmentally favorable process for the preparation of brominated butyl rubbers, that uses a bromination agent and a oxidizing agent in order to enhance the utilization of bromine contained in the bromination agent. In a preferred embodiment a common medium for both solution polymerization and subsequent bromination of the rubber is employed.

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: Described are a particular group of novel aromatic hydrocarbon telomers that, on bromination, result in the formation of novel flame retardants having a uniquely beneficial combination of properties. The resultant flame retardants and uses thereof are also described. The disclosure includes descriptions of methods for preparing both the aromatic hydrocarbon telomers and the brominated flame retardant polymers.

Abstract: A polyalkenyl succinic anhydride is prepared with low amounts of resinous or chlorinated byproducts in a two-step process whereby a polyalkene is first reacted with an unsaturated organic acid in a thermal ene reaction, followed with exposure to a gaseous halogen in presence of an additional amount of the unsaturated organic acidic reagent. The foregoing process produces a polyisobutenyl succinic anhydride having a high ratio of succinic anhydride functional groups to polyisobutenyl backbone groups. Such a polyisobutenyl succinic anhydride is particular suitable for the production of oil-soluble hydrocarbyl succinimides that have good dispersant properties when added to lubricating oil compositions.

Abstract: The present invention provides a method for producing a stabilized fluoropolymer which comprises producing the stabilized fluoropolymer by subjecting a treatment target substance containing a sulfonic-acid-derived-group-containing fluoropolymer to a fluorination treatment, wherein the sulfonic-acid-derived-group-containing fluoropolymer is a fluoropolymer containing —SO3M (in which M represents H, NR1R2R3R4 or M11/L; R1, R2, R3 and R4 are the same or different and each represents H or an alkyl group containing 1 to 4 carbon atoms; and M1 represents an L-valent metal), and the treatment target substance has a moisture content of not higher than 500 ppm by mass.

Abstract: The disclosure describes methods of metathesizing unsaturated organic compounds, each method comprising contacting at least one feedstock comprising at least one olefinic or acetylenic precursor with a solid transition metal-based metathesis catalyst in the absence of a liquid solvent or precursor to form a polymer product.

Abstract: A composition and method of making having a perfluoroelastomer gum with a nitrogen-containing cure site and an end group represented by —CF3—CF2H, —CFH2, and/or —CH3, and having a low carbonyl-containing end group ratio, which yield cured fluoroelastomers with improved retained sealing force and articles therefrom.

Abstract: The present disclosure relates to a process for neutralizing a sulfonated block copolymer with a metal compound, to metal-neutralized block copolymers, and to various articles comprising the metal-neutralized block copolymers, e.g., in form of a water vapor permeable membrane which comprises the metal-neutralized block copolymers. The present disclosure further relates to a means and a method for storing and stabilizing a polar component such as a metal compound in a non-polar liquid phase by immuring the polar component in micelles of the sulfonated block copolymer in the non-polar liquid phase.

Abstract: Preparing brominated styrenic polymer by maintaining a mixture formed from (i) brominating agent, (ii) a solvent solution of styrenic polymer, and (iii) aluminum halide catalyst, at ?20 to +20° C., and terminating bromination in 20 minutes or less. New brominated anionic styrenic polymers have better melt flow and/or lower initial ?E values than the best previously-known brominated anionic styrenic polymers. Other features of such new polymers include high thermal stabilities at 320° C. and/or very low initial color values. Brominated styrenic polymers, especially brominated anionic styrenic polymers, are useful as flame retardants for thermoplastic polymers.

Abstract: Butadiene copolymers are brominated in solution using bromine as the brominating agent. The bromination is conducted in the presence of an excess of an aliphatic alcohol, relative to the amount of bromine that is used. The bromination proceeds rapidly at mild conditions, and is selective in that only aliphatic carbon-carbon double bonds are brominated, and unwanted bromination at tertiary carbon atoms is largely or completely avoided. The resulting brominated polymers are characterized in having very good thermal stability.

Abstract: Concurrently fed into a reaction zone held at about 10° C. or less are brominating agent, aluminum halide catalyst, and a solution of anionic styrenic polymer having a GPC Mn about 2000-30,000. The components are in at least two separate feed streams. The feeds are proportioned to maintain (a) the amount of aluminum halide being fed at about 0.8 mole percent or less based on the amount of aromatic monomeric units in the polymer being fed, and (b) amounts of brominating agent and unbrominated polymer in the reaction zone that produce a final washed and dried polymer product containing about 60-71 wt % bromine. The catalyst is deactivated, bromide ions and catalyst residues are washed away from the reaction mixture, and the brominated anionic styrenic polymer is recovered and dried. The dried polymer has a volatile bromobenzene content of about 600 ppm (wt/wt) or less as well as other beneficial properties.

Abstract: New branched or star-branched styrene polymeric, telomeric, and monomeric product distributions, their preparation, their use as raw materials for bromination to produce flame retardants, the flame retardants themselves, and their use as flame retardants in various polymeric substrates are described.

Abstract: A polyalkenyl succinic anhydride is prepared with low amounts of resinous or chlorinated byproducts in a two-step process whereby a polyalkene is first reacted with an unsaturated organic acid in a thermal ene reaction, followed with exposure to a gaseous halogen in presence of an additional amount of the unsaturated organic acidic reagent. The foregoing process produces a polyisobutenyl succinic anhydride having a high ratio of succinic anhydride functional groups to polyisobutenyl backbone groups. Such a polyisobutenyl succinic anhydride is particular suitable for the production of oil-soluble hydrocarbyl succinimides that have good dispersant properties when added to lubricating oil compositions.

Abstract: The residual chlorine content of a polyolefin-substituted carboxylic acylating agent formed by a halogen-assisted reaction of a polyalkene and at least one olefinic, monounsaturated mono- or dicarboxylic acid, anhydride or ester, is reduced when the reaction is conducted in the presence of a controlled amount of a metal compound.

Abstract: Concurrently fed into a reaction zone held at about 10° C. or less are brominating agent, aluminum halide catalyst, and a solution of anionic styrenic polymer having a GPC Mn about 2000-30,000. The components are in at least two separate feed streams. The feeds are proportioned to maintain (a) the amount of aluminum halide being fed at about 0.8 mole percent or less based on the amount of aromatic monomeric units in the polymer being fed, and (b) amounts of brominating agent and unbrominated polymer in the reaction zone that produce a final washed and dried polymer product containing about 60-71 wt % bromine. The catalyst is deactivated, bromide ions and catalyst residues are washed away from the reaction mixture, and the brominated anionic styrenic polymer is recovered and dried. The dried polymer has a volatile bromobenzene content of about 600 ppm (wt/wt) or less as well as other beneficial properties.

Abstract: Preparing brominated styrenic polymer by maintaining a mixture formed from (i) brominating agent, (ii) a solvent solution of styrenic polymer, and (iii) aluminum halide catalyst, at ?20 to +20° C., and terminating bromination in 20 minutes or less. New brominated anionic styrenic polymers have better melt flow and/or lower initial ?E values than the best previously-known brominated anionic styrenic polymers. Other features of such new polymers include high thermal stabilities at 320° C. and/or very low initial color values. Brominated styrenic polymers, especially brominated anionic styrenic polymers, are useful as flame retardants for thermoplastic polymers.

Abstract: A method for hydrogenation of a conjugated diene polymer is provided. The conjugated diene polymer in an inert organic solvent is brought into contact with hydrogen in the presence of a hydrogenation catalyst composition to selectively hydrogenate the unsaturated double bonds in the conjugated diene units of the conjugated diene polymer. The hydrogenation catalyst composition includes: (a) a titanium compound; (b) a compound represented by formula (II) or formula (III): wherein R is C1-C12 alkyl, C3-C12 cycloalkyl, aryl or alkyl aryl, M is C1-C12 alkyl, C1-C12 alkoxy, aryl, alkyl aryl, phenoxy or hydroxyl, and n=1˜3; and (c) a alkylaluminum compound.

Abstract: At least partially neutralized chlorosulfonated ethylene/alpha-olefin elastomers containing 0.5-10 weight percent chlorine and 0.25 to 5 weight percent sulfur are prepared from ethylene/alpha-olefin copolymer base resins having a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) less than 3.5.

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: The present invention relates to a method for recovering antimony catalysts wherein the formation of insoluble solids is reduced.

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: An object of the present invention is to provide a heavy metal ion scavenger having more excellent scavenging performance than previously. In order to attain this object, organic polymer materials of the present invention are characterized in that they have a polymer side chain derived from a haloalkyl-substituted styrene on the backbone of an organic polymer base and a functional group capable of forming a complex with a heavy metal ion has been introduced onto said polymer side chain. These organic polymer materials have excellent heavy metal ion scavenging performance so that they can be suitably used as heavy metal ion scavengers.

Abstract: The present invention is to provide a continuous anion polymerization method for preparing transparent high impact vinyl aromatic polymer comprising the steps of: i) charging and polymerizing vinyl aromatic monomers and initiator to obtain vinyl aromatic polymer in the presence of solvent and polar organic compounds in the first reactor (1a); ii) continuously charging and polymerizing vinyl aromatic monomers and conjugated diene monomers to the vinyl aromatic polymer obtained in the first reactor to obtain tapered vinyl aromatic polymer chain in the presence of organic solvent in the second reactor (1b); iii) continuously charging and polymerizing vinyl aromatic monomers and multi-functional compounds to the vinyl aromatic polymer chain obtained in the second reactor to obtain high impact vinyl aromatic polymer in the presence of organic solvent in the third reactor (1c); and iv) terminating the reaction with terminator and removing the remaining hydrocarbon solvent and unreacted monomers to obtain transparen

Abstract: Monofunctional polyfluorooxetane oligomers and polymers are prepared by the cationic polymerization of fluorooxetane monomers with a monoalcohol. The fluorooxetane oligomers or polymers can be copolymerized with generally cyclic ethers. Alternatively, the polyfluorooxetane oligomer or polymer having a single hydroxyl end group can be functionalized with a variety of compounds so as to yield a functional end group such as an acrylate, a methacrylate, an allylic, an amine, etc., with the functionalized oligomer or polymer being suitable for use in radiation curable or thermal curable coating compositions. These functionalized polymers can be copolymerized and cured to provide improvements in wetting and surface properties that have previously been provided by migratory chemicals such as waxes and oils.

Abstract: A brominated polystyrene product made by the process comprising pretreating a solution of a polystyrene reactant comprising from about five to about 20 percent by weight of the polystyrene reactant, in a halogenated hydrocarbon solvent with at least about 0.1 percent by weight of an additive to suppress halogenation of the polystyrene backbone, prior to brominating the polystyrene in the presence of a catalyst; subsequently adding a metal halide bromination catalyst to the solution, capable of effecting bromination of the ring without causing crosslinking of the polystyrene; adding to the solution from about 1 to about 3.4 moles of a brominating agent, per mole of polystyrene repeating units; reacting the polystyrene with the brominating agent at a temperature of from about −20° C. to about 50° C., and isolating the brominated polystyrene. A brominated polystyrene is provided having a backbone halogen content of less than about 750 ppm and a &Dgr;E color of from about 5 go about 19.

Abstract: Monofunctional polyfluorooxetane oligomers and polymers Zare prepared by the cationic polymerization of fluorooxetane monomers with a monoalcohol. The fluorooxetane oligomers or polymers can be copolymerized with generally cyclic ethers. Alternatively, the poly-fluorooxetane oligomer or polymer having a single hydroxyl end group can be functionalized with a variety of compounds so as to yield a functional end group such as an acrylate, a methacrylate, an allylic, an amine, etc., with the functionalized oligomer or polymer being suitable for use in radiation curable or thermal curable coating compositions. These functionalized polymers can be copolymerized and cured to provide improvements in wetting and surface properties that have previously been provided by migratory chemicals such as waxes and oils.

Abstract: Monofunctional polyfluorooxetane oligomers and polymers are prepared by the cationic polymerization of fluorooxetane monomers with a monoalcohol. The fluorooxetane oligomers or polymers can be copolymerized with generally cyclic ethers. Alternatively, the polyfluorooxetane oligomer or polymer having a single hydroxyl end group can be functionalized with a variety of compounds so as to yield a functional end group such as an acrylate, a methacrylate, an allylic, an amine, etc., with the functionalized oligomer or polymer being suitable for use in radiation curable or thermal curable coating compositions. These functionalized polymers can be copolymerized and cured to provide improvements in wetting and surface properties that have previously been provided by migratory chemicals such as waxes and oils.

Abstract: Monofunctional polyfluorooxetane oligomers and polymers are prepared by the cationic polymerization of fluorooxetane monomers with a monoalcohol. The fluorooxetane oligomers or polymers can be copolymerized with generally cyclic ethers. Alternatively, the polyfluorooxetane oligomer or polymer having a single hydroxyl end group can be functionalized with a variety of compounds so as to yield a functional end group such as an acrylate, a methacrylate, an allylic, an amine, etc., with the functionalized oligomer or polymer being suitable for use in radiation curable or thermal curable coating compositions. These functionalized polymers can be copolymerized and cured to provide improvements in wetting and surface properties that have previously been provided by migratory chemicals such as waxes and oils.

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: Graft copolymers having cationic units pendant to the backbone chain are disclosed. These polymers are prepared by reacting a polymer containing halogenated para-methylstyrene units in the chain, e.g., a brominated copolymer of isobutylene and para-methylstyrene, with an anionically polymerized polymer made using an organolithium initiator compound having the formula R1 R2 Z R3—Li where R1 and R2 are alkyl radicals, R3 is a direct link or an organic radical and Z is nitrogen or phosphorous. Reaction of the anionically polymerized polymer having an R1 R2 Z R3— end group with the halogenated polymer leads to graft polymers coupled by a quaternary ammonium or phosphonium groups.

Abstract: A brominated polystyrene product made by the process comprising pretreating a solution of a polystyrene reactant comprising from about five to about 20 percent by weight of the polystyrene reactant, in a halogenated hydrocarbon solvent with at least about 0.1 percent by weight of an additive to suppress halogenation of the polystyrene backbone, prior to brominating the polystyrene in the presence of a catalyst; subsequently adding a metal halide bromination catalyst to the solution, capable of effecting bromination of the ring without causing crosslinking of the polystyrene; adding to the solution from about 1 to about 3.4 moles of a brominating agent, per mole of polystyrene repeating units; reacting the polystyrene with the brominating agent at a temperature of from about −20° C. to about 50° C., and isolating the brominated polystyrene. A brominated polystyrene is provided having a backbone halogen content of less than about 750 ppm and a &Dgr;E color of from about 5 go about 19.

Abstract: This invention relates to the bromination of styrenic polymers by contacting same with a brominating agent in the presence of a bromination catalyst and, as a reaction solvent, bromochloro-methane.

Abstract: A transition metal complex of a polymer of 2'-diarylphosphino-1,1'-biphenylen-2-yloxy(6,6'-divinyl-1,1'-binaphthalene -2,2'-diyloxy)phosphine derivative is disclosed, which is represented by general formula (I): ##STR1## wherein Ar is an optionally substituted phenyl or naphthyl; R.sup.1 and R.sup.2 each independently is a hydrogen atom, a lower alkyl, a lower alkoxy, etc.; and R.sup.3 is a lower alkyl, a lower alkoxy, etc.; provided that R.sup.2 and R.sup.3 may be bonded to each other to form a hydrocarbon ring, which may have one or more substituents selected from lower alkyl groups, halogen atoms, vinyl, etc. Also disclosed are a polymer having structural units derived from the phosphine derivative and a transition metal complex obtained by causing a transition metal compound to act on the phosphine derivative or the polymer. A novel polymer-supported ligand is provided which, when used as a catalyst for asymmetric syntheses, gives satisfactory results concerning catalytic activity, enantiomer excess, etc.

Abstract: The present invention provides a method of producing a flame-retardant polymer comprising mixing one or more polymeric base resins with a source of brominated syndiotactic polystyrene that displays a noncrystalline order and is produced by a process comprising brominating syndiotactic polystyrene in an inert reaction medium that is incapable of dissolving to any appreciable degree syndiotactic polystyrene at ambient temperature and pressure. The produced brominated syndiotactic polystyrene has a melting temperature in excess of about 325.degree. C.

Abstract: The present invention provides a new flame-retardant additive comprising brominated syndiotactic polystyrene. The additive has a melting temperature in excess of about 325.degree. C. and it displays a noncrystalline order. The additive also has less than 1500 ppm halogen located on the backbone of the syndiotactic polystyrene as measured in HBr equivalents. The additive provides for better color and improved thermal stability as compared to the use of conventional brominated polystyrene.

Abstract: A process for improving the processability of poly(arylene sulfide) in melt spinning operations by treatment with a barium-containing compound and, optionally, a lubricant is disclosed.

Abstract: This invention pertains to a method for liquid phase fluorination for perfluorination of a wide variety of hydrogen-containing compounds.

Abstract: In a process for the suppression of backbone halogenation during the bromination of polystyrenes comprising the step of pretreating a solution of a polystyrene reactant comprising from about five to about 20 percent by weight of a polystyrene reactant, in a halogenated hydrocarbon solvent with at least about 0.1 percent by weight of an additive to suppress halogenation of the polystyrene backbone prior to brominating the polystyrene in the presence of a catalyst; adding a metal halide bromination catalyst to the solution, capable of effecting bromination of the ring without causing crosslinking of the polystyrene; adding to the solution from about 1 to about 3.4 moles of a brominating agent, per mole of polystyrene repeating units; reacting the polystyrene reactant with the brominating agent at a reaction temperature of from about -20.degree. C. to about 50.degree. C., and isolating the brominated polystyrene.

Abstract: This invention pertains to a method for liquid-phase fluorination for perfluorination of a wide variety of hydrogen-containing compounds.

Abstract: In a process for the suppression of backbone halogenation during the bromination of polystyrenes comprising the step of pretreating a solution of a polystyrene reactant comprising from about five to about 20 percent by weight of a polystyrene reactant, in a halogenated hydrocarbon solvent with at least about 0.1 percent by weight of an additive to suppress halogenation of the polystyrene backbone prior to brominating the polystyrene in the presence of a catalyst; adding a metal halide bromination catalyst to the solution, capable of effecting bromination of the ring without causing crosslinking of the polystyrene; adding to the solution from about 1 to about 3.4 moles of a brominating agent, per mole of polystyrene repeating units; reacting the polystyrene reactant with the brominating agent at a reaction temperature of from about -20.degree. C. to about 50.degree. C., and isolating the brominated polystyrene.

Abstract: The present invention provides a new method for making an improved flame-retardant additive comprising a brominated syndiotactic styrenic polymer. The method includes the steps of providing a source of syndiotactic styrenic polymer; providing a source of inert reaction medium that is not capable of dissolving to any appreciable degree the syndiotactic styrenic polymer at ambient temperature and pressure; providing a source of brominating agent; providing a source of Lewis acid catalyst; mixing the syndiotactic styrenic polymer with the inert reaction medium and the Lewis acid catalyst; and reacting the syndiotactic styrenic polymer with the brominating agent to produce a brominated syndiotactic styrenic polymer.

Abstract: Seeded cation-exchange resin beads are particularly susceptible to oxidative degradation which results in the leaching of organic carbon fragments. The leachability of organic carbon fragments of molecular weights greater than 1000 g/mol is reduced to less than 800 ppm by effectively crosslinking the copolymers that comprise the seeded cation-exchange resin beads. Crosslinking can be achieved either during sulfonation by increasing sulfone bridge formation or before sulfonation by either alkylene bridge formation or by incorporation and subsequent activation of a crosslinkable functionality in the copolymer that forms the seed in the seeded polymer bead process.

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 method of compatibilizing a blend of at least a hydrocarbon polymer with at least one other polymer which is incompatible with the hydrocarbon polymer, said method comprising adding to the polymer blend a compatibilizer which is an isoolefin/para-alkylstyrene copolymer represented by the formula ##STR1## in which R and R' can be hydrogen, alkyl, and the primary and secondary alkyl halides, "a" ranges from about 14 to about 70,000, "b" ranges from 0 to about 70,000, "c" ranges from 0 to about 70,000, "d" ranges from about 1 to about 70,000, X is a halogen, and Nu is a nucleophilic residue provided by a polymeric nucleophile.

Abstract: Graft copolymers which are isoolefin/para-alkylstyrene copolymer represented by the formula ##STR1## in which R and R' can be hydrogen, alkyl, and the primary and secondary alkyl halides, "a" ranges from about 14 to about 70,000, "b" ranges from 0 to about 70,000, "c" ranges from 0 to about 70,000, "d" ranges from about 1 to about 70,000, X is a halogen, and Nu is a nucleophilic residue provided by a polymeric nucleophile.

Abstract: This invention pertains to perfluoropolyethers and perhalogenated chlorofluoropolyethers that can be prepared by fluorinating addition polymers made by polymerizing epoxides.

Abstract: Disclosed is a process for preparing a brominated polystyrene, which comprises reacting a polystyrene dissolved or dispersed in a halogenated hydrocarbon type solvent, with a brominating agent in the presence of an antimony oxide catalyst.

Abstract: In a process for the suppression of backbone halogenation during the bromination of polystyrenes comprising the step of pretreating a solution of a polystyrene reactant comprising from about five to about 20 percent by weight of a polystyrene reactant, in a halogenated hydrocarbon solvent with at least about 0.1 percent by weight of an additive to suppress halogenation of the polystyrene backbone prior to brominating the polystyrene in the presence of a catalyst; adding a metal halide bromination catalyst to the solution, capable of effecting bromination of the ring without causing crosslinking of the polystyrene; adding to the solution from about 1 to about 3.4 moles of a brominating agent, per mole of polystyrene repeating units; reacting the polystyrene reactant with the brominating agent at a reaction temperature of from about −20° C. to about 50° C., and isolating the brominated polystyrene.