Poly brominated

Membranes and Osmosis. Membranes based on PEI can be used for the dehydration of organic solvents such as 2-propanol, methyl ethyl ketone, and toluene (451), and for concentrating seawater (452—454). On exposure to ultrasound waves, aqueous PEI salt solutions and brominated poly(2,6-dimethylphenylene oxide) form stable emulsions from which it is possible to cast membranes in which submicrometer capsules of the salt solution ate embedded (455). The rate of release of the salt solution can be altered by surface—active substances. In membranes, PEI can act as a proton source in the generation of a photocurrent (456). The formation of a PEI coating on ion-exchange membranes modifies the transport properties and results in permanent selectivity of the membrane (457). The electrochemical testing of salts (458) is another possible appHcation of PEI. 

Tsou and Measmer examined the dispersion of organosUicates on two different butyl mbbers, namely BIMS and brominated poly(isobutylene-co-isoprene) (BIIR) with the help of small angle X-ray scattering (SAXS), wide angle X-ray scattering (WAXS), atomic force microscopy (AFM), and TEM [91]. There is also a patent on BIMS nanocomposites for low permeability and their uses in tire inner tubes [92]. 

FIGURE 2.11 Plot of oxygen transmission rate versus time for brominated poly(isobutylene-co-isoprene) (BIMS) nanocomposite. 

Brominated poly(isobutylene-co-4-methyl styrene) (BIMS) is often blended with general-purpose mbbers (NR, BR, SBR, etc.) for producing articles such as tire-forming bladders, treads, and side walls. 

FIGURE 11.12 Interaction energy density versus 4-methyl styrene content. (From Raboney, M., Gamer, R.T., Elspass, C.W., and Peiffer, D.G., Phase Behavior of Brominated Poly(Isobutylene-co-4-Methylstyrene)/ General Purpose Rubber Blends. Rubber Division, Proceedings of the American Chemical Society, Nashville, TN, Sept. 29-Oct. 2, 1998, Paper No. 36.)... 

Verdet and Stille1 employed brominated poly(phenylene oxide) intermediates in an effort to synthesize more stable catalyst supports containing (cyclopentadienyl)metal complexes. Treatment of poly(oxy-2,6-dimethyl-l,4-phenylene) with N-bromosuccinimide under photolytic conditions produced only the bromomethyl derivative if the D.F. did not exceed 0.35. Subsequent treatment of the bromomethylated polymer with sodium cyclopentadienide afforded the cyclopentadienyl functionalized polymer, 5, but the reaction was accompanied by crosslinking and it was not possible to remove the bromomethyl substituents quantitatively. 

Brominated diphenyl oxides, 77 461 Brominated epoxies, 70 383 Brominated epoxy ohgomers, 77 470 Brominated epoxy resin, 70 456 Brominated poly(isobutylene-co-p-methylstyrene), 4 438 blends with halobutyl, 4 453 copolymers, 4 446 vulcanization, 4 450 Brominated polystyrene(s), 77 470 474 20 65... 

Di(dibromomethyl)benzene is reduced at a mercury cathode to yield the poly(p-phenylenevinylene) 41. The reaction proceeds through a brominated poly-... 

The curing of brominated poly(isobutylene-co-4-methylstyrene) by pure ZnO was studied by solid-state TT and 13C MAS NMR [48]. From NMR results, crosslinking appears to occur by aromatic ring addition of the benzylic carbocation generated from an intermediate PhCH2-Br-Zn complex. 

Another good example of using Raman spectroscopy in the polymer industry is to investigate polymer blends. Raman microimages have been used to investigate the spatial distributions of the components in a blend of brominated poly(isobutylene-co-para-methylstyrene (BIMS) and cis-1-4-polybutadiene (BR) containing silica, zinc stearate, thiate, and other additives (21). A Raman spectrum of a blend is shown in Fig. 7-33. Specific bands can be assigned to BIMS, BR, silica, and zinc stearate. A 10 x 10 xm contour... 

Brominated poly(l-trimethylsilylpropyne) is an example of a substituted polyacetylene that is suitable for bilevel-resist processes (34). Requiring both exposure and postexposure bake (PEB) steps, samples of the polypropyne having a mole fraction of bromine from 0.1 to 0.2 per monomer unit exhibit sensitivities in the order of 25 mj/cm. Submicrometer resolution has been demonstrated, and etching-rate ratios relative to hard-baked photoresist planarizing layers are —1 25. 

Under standard conditions (N-bromosuccinimide [NBS] and AIBN [azo-bis(isobutyronitrile)] in refluxing CCI4), the desired brominated poly(TMSP) products were formed in high yield. Nearly quantitative yields were obtained up to bromination levels of 50%, on the basis of one Br substitution per monomer unit, but unexpectedly, the maximum attainable bromination level was only 60%, even when a large excess of NBS was used (Table I). We attributed this curious behavior to the extreme steric crowding at the allylic methyl groups in the polymer structure. The accessibility of the allylic sites apparently is so limited that monobromination is the exclusive reaction, and the presence of the bulky halogen decreases the likelihood of bromination at adjacent allylic sites. Similar results were obtained when benzoyl peroxide was used as the free-radical source. 

Figure 4. UV-visible spectra of brominated poly(TMSP) in cyclohexane (c — 0.03 giL). The absorbance scale is that for the unbrominated material the absorption curves for the brominated polymers have been normalized to that of the unbrominated material for clarity. Sample designations are explained in the caption to Figure 2.

The bilayer scheme was successfully demonstrated with lightly brominated poly(TMSP) (—10% Br). In these experiments, a 3000-A layer of the brominated polymer was deposited on top of 1.5 (xm of polyimide or novolac planarizing layers. The wafer was exposed to 25 mj/cm of deep-UV radiation and heated for 1 h at 140 °C. The pattern was developed in... 

Figure 10. IR spectra of brominated poly(TMSP) (10% Br) before (A) and after (B) exposure to 50 mj/cm of deep-UV radiation and a l h heat treatment...

Table II. Degradation of Brominated Poly(TMSP) (40-Br) Films...

Scheme 1, Proposed photochemical pathways for brominated poly(TMSP). TMS indicates the trimethylsilyl group.

The use of brominated poly(TMSP) as a chemical intermediate has recently been described in the patent literature. Tanaka, H. Morita, M. Japanese Patent 61 105 544, 1986. 

The method described here uses a monoclonal anti-Z-DNA andbody Z22 (12). This can be subsdtuted by other monoclonal or polyclonal andbodies. Rabbits or goat could be immunized with brominated poly (dG-dC).poly(dG-dC) to produce polyclonal and-Z-DNA andbody. This polynucleodde exists in the Z-DNA conformadon at 150 mAf NaCl. 

Composites of polypyrrole and poly(vinyl chloride) have been prepared by several groups (64-67). Polythiophene-poly(vinyl chloride) composites have also been prepared (68). The electropolymerization of pyrrole on poly(vinyl chloride)-coated electrodes yielded composites with mechanical properties (tensile strength, percent elongation at break, percent elongation at yield) similar to poly(vinyl chloride) (65) but with a conductivity of 5-50 S/cm, which is only slightly inferior to polypyrrole (30-60 S/cm) prepared under similar conditions. In addition, the environmental stability was enhanced. Morphological studies (69) showed that the polypyrrole was not uniformly distributed in the film and had polypyrrole-rich layers next to the electrode. Similarly, poly(vinyl alcohol) (70) poly[(vinylidine chloride)-co-(trifluoroethylene)] (69) and brominated poly(vinyl carbazole) (71) have been used as the matrix polymers. The chemical polymerization of pyrrole in a poly(vinyl alcohol) matrix by ferric chloride and potassium ferricyanide also yielded conducting composites with conductivities of 10 S/cm (72-74). 

Phosphite-functionalized polymers were prepared by llthlatlon of brominated poly(styrene-DVB) membranes or beads followed by hydroxyethylation with ethylene oxide and phosphitation with chlorodlalkylphosphlte and a base dlmethylanillne was found to be most suitable (22). Dlmethylanillne hydrochloride, which is formed in the reaction, is highly soluble in chloroform and thus can be conveniently removed without the need for a more polar solvent which may cause solvolysis of the attached... 

The product of the interaction of chlorine gas with poly-DCH was studied by scanning electron microscopy (SEM) our SEM studies of pristine and brominated poly-DCH were previously rep>orted (lb). A sample at magnification 1500 is shown in Figure 1. Compared to pristine p>oly-DCH, Figure 1 reveals that a fibrous morphology is reUuned, but the fibers of the chlorinated polymer appear thicker and rougher than those of the reactant. 

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