Polystyrene bromination

Preparation of Macromolecular Dioxolenium Salts. Living polystyrene prepared by the polymerization of styrene in THF with a-methylstyrene tetramer dianion reacted with a 2.1-molar amount of ethylene oxide for three hours at room temperature a 6.6-molar amount of adipoyl chloride was added, and the mixture was stirred for 20 horns a 20-molar amount of ethylenebromohydrin was added. This mixture was stirred for 44 hours. The bromoethylated polystyrene was precipitated in excess methanol and freeze-dried from benzene in a vacuum system. A 1-nitropropane solution of polystyrene dioxolenium salt was prepared by reaction of bromoethylated polystyrene with silver perchlorate in 1-nitropropane. Silver bromide was removed from the reaction mixture by filtration. Molecular weight of the product was measured by a vapor-pressure osmometer it was 1910 for living polystyrene and 5190 for the bromoethylated polystyrene. Bromine analysis of the bromoethylated polystyrene showed 67.9% of the calculated value. 

Diaion SP20SS. See Polystyrene Diaion SP207. See Polystyrene, brominated Diaion SP825] Diaion SP85a, Diaion UBK53a, Diaion UBK55a, Diaion UBK555. See Polystyrene... 

Polystyrene/acrylonitrile. See Styrene/acrylonitrile copolymer Polystyrene benzyltrimethylaminonium chloride. See Cholestyramine Polystyrene-block-poly (ethylene-ran-butylene)-block-polystyrene. See Styrene-ethylene/butylene-styrene block copolymer Polystyrene, brominated CAS 88497-56-7... 

Pyrocatechol methyl ether. See Guaiacol Pyrocatechuic acid. See Pyrocatechol Pyrocellulose. See Cellulose Pyro-Chek 60PB, Pyro-Chek 60PBC, Pyro-Chek 68PB, Pyro-Chek 68PBC, Pyro-Chek 68PBG, Pyro-Chek LM. See Polystyrene, brominated... 

N,N -Bis (tetrabromophthalimide) Ethylenebis (tetrabromophthalimide) Melamine cyanurate Pentabromobenzyl acrylate Polystyrene, brominated... 

Tribromophenyl allyl ether flame retardant, polyamides Ethylenebis dibromonorbornane dicarboximide Melamine cyanurate Octabromodiphenyl oxide Phosphorus, red Polystyrene, brominated Resorcinol bis (diphenylphosphate) flame retardant, polybutylenes Tetrabromobisphenol A, bis (2,3-dibromopropyl ether) flame retardant, polyester fabrics Methylphosphonic acid, bis [(5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl) methyl] ester... 

For solid polystyrenes, brominated aromatics are the most frequently used flame-retardants. Brominated diphenyls and diphenyl oxides rather than pentabromotoluene are popular due to their higher thermal stability, especially for high-impact PS and ABS processed at higher temperatures. The most commonly used agent for the latter products is decabromodiphenyl oxide. Rating V-0 is achieved with 12 to 15 per cent of this compound with 4 to 5 per cent of SbaOa. Flame-retardant FF 680 of Great Lakes is mainly recommended for ABS. " ... 

Poly(dibromostyrene). Poly(dibromostyrene) [62354-98-7] (PDBS) is prepared by the polymerization of dibromostyrene [31780-26-4] (50). Two versions are avaHable. One has a molecular weight of about 10,000, the other a molecular weight of about 80,000. Information comparing the performance of these materials to the performance of the brominated polystyrenes is not avaHable. 

Flame Retardants. Flame retardants are added to nylon to eliminate burning drips and to obtain short self-extinguishing times. Halogenated organics, together with catalysts such as antimony trioxide, are commonly used to give free-radical suppression in the vapor phase, thus inhibiting the combustion process. Some common additives are decabromodiphenyl oxide, brominated polystyrene, and chlorinated... 

Amos prepared his polymer-supported reagent in two steps from commercially available polystyrene beads (bromination, then condensation with lithium diphenylphosphide). He found that a useful range of sulphoxides could be reduced effectively, in good yields and in a few hours, to give clean samples of sulphides. 

Silane radical atom transfer (SRAA) was demonstrated as an efficient, metal-free method to generate polystyrene of controllable molecular weight and low polydispersity index values. (TMSlsSi radicals were generated in situ by reaction of (TMSlsSiH with thermally generated f-BuO radicals as depicted in Scheme 14. (TMSlsSi radicals in the presence of polystyrene bromide (PS -Br), effectively abstract the bromine from the chain terminus and generate macroradicals that undergo coupling reactions (Reaction 70). 

For the large scale synthesis, the sodium salt of 2 formed in the NaCN-NaOH reaction could be purified by brominated polystyrene resin S P-207 chromatography to avoid acidic work-up which generates HCN. The SP-207 resin was first saturated with 1 M NaCl, and the crude reaction mixture was loaded onto the column. The column was then eluted with 1M NaCl to remove inorganic salts such as excess NaCN and NaOH and other polar impurities. Eluant switching to MeOH-H20 eluted the sodium salt of 2. Fractions containing >98.5 A% of... 

The synthesis of luminescent organoboron quinolate polymers (21) (Fig. 15) via a three-step procedure starting from a silylated polystyrene has been communicated. The synthesis was initiated by the highly selective borylation of poly (4-trimethylsilylstyrene) (PS-Si), followed by the replacement of the bromine substituents in poly(4-dibromoborylstyrene) (PS-BBr) with substituted thienyl groups (R = H, 3-hexyl, 5-hexyl). In the final step, the 8-hydroxyquinolato moiety was introduced. The hexyl-substituted polymers efficiently emitted light at 513-514nm upon excitation at 395 nm.40... 

Polystyrene/polyethylene oxide dendrimers were prepared by ATRP using tri- and tetra (bromomethyl) benzene as the initiators [207]. Each bromine end-group of the resulting stars was transformed first to two - OH groups and subsequently to potassium alcholate, as shown in Scheme 114. These - OK sites served to initiate the anionic polymerization of EO. The synthesized dendritic copolymers were found to display monomodal and narrow molecular weight distribution. 

Experiments pertaining to a new system for the application of bromine to flame retardant polypropylene and foamed polystyrene are described. The FR compound, ammonium bromide, is formed in the amorphous regions of the polymer phase by the interaction of bromine sorbed on the polymer and ammonia, sorbed subsequently. Gaseous nitrogen which is also produced, expands and brings about the rearrangement of the chains to produce a porous structure. The ammonium bromide produced is finely divided and imparts FR properties to the polymer. 

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