Liquid polymers poly

Caulking compound (liquid polymer poly sulfide synthetic rubber formula 112 for metal enclosures)... 

A liquid polymer, poly[(phenyl isocyanate)-co-formaldehyde, containing one isocyanate group on each of the phenyl rings, was used to cross-link with an optically active second-order material of 4-[ AT-(2-hydroxyethyl)-A -methylamino phenyl]-4 -[(6-hydroxyhexyl)sulfonyl]azobene [146] (Scheme 17). The corona-poled and thermally developed polymer films revealed a... 

VV -values for bromoform and pyrrole, acidic liquids, against poly(vinyl chloride), an acidic polymer, and dimethyl sulfoxide, a predominantly basic liquid, against polyfmethyl methacrylate), a basic polymer, but large values for the acidic liquids against PMMA and the basic liquid against PVC. 2-Iodoethanol, a bifunctional liquid, showed appreciable -values with both polymers. Despite these results in line with expectations, other results based on wettability measurements are not so clear-cut. For example, Vrbanac [94] found significant apparent acid-base interactions of various aromatic liquids against poly(ethylene), presumably a neutral substrate. 

Ionic liquids have already been demonstrated to be effective membrane materials for gas separation when supported within a porous polymer support. However, supported ionic liquid membranes offer another versatile approach by which to perform two-phase catalysis. This technology combines some of the advantages of the ionic liquid as a catalyst solvent with the ruggedness of the ionic liquid-polymer gels. Transition metal complexes based on palladium or rhodium have been incorporated into gas-permeable polymer gels composed of [BMIM][PFg] and poly(vinyli-dene fluoride)-hexafluoropropylene copolymer and have been used to investigate the hydrogenation of propene [21]. 

Sealants obtained by curing polysulfide liquid polymers with aryl bis(nitrile oxides) possess stmctural feature of thiohydroximic acid ester. These materials exhibit poor thermal stability when heated at 60°C they soften within days and liquefy in 3 weeks. Products obtained with excess nitrile oxide degrade faster than those produced with equimolar amounts of reagents. Spectroscopic studies demonstrate that, after an initial rapid addition between nitrile oxide and thiol, a second slower reaction occurs which consumes additional nitrile oxide. Thiohydroximic acid derivatives have been shown to react with nitrile oxides at ambient temperature to form 1,2,4-oxadiazole 4-oxides and alkyl thiol. In the case of a polysulfide sealant, the rupture of a C-S bond to form the thiol involves cleavage of the polymer backbone. Continuation of the process leads to degradation of the sealant. These observations have been supported by thermal analysis studies on the poly sulfide sealants and model polymers (511). 

M. Grell, D.D.C. Bradley, X. Long, T. Chamberlain, M. Inbasekaran, E.P. Woo, and M. Soliman, Chain geometry, solution aggregation and enhanced dichroism in the liquid-crystalline conjugated polymer poly(9,9-dioctylfluorene), Acta Polym., 49 439-444, 1998. 

Work with supported ionic liquids was extended to a cationic polymer, poly (diallyldimethylammonium chloride), which has quaternary ammonium functional groups (Fig. 16) 268). The extra-structural counter anion is Cl . The polymer was applied to simultaneously incorporate an ionic liquid and a transition-metal catalyst via a simple mixing of the components. Wilkinson s catalyst and [BMIM]PF6 were... 

The order and mobility of a labeled flexible alkyl spacer in the linear thermotropic polymeric nematic liquid crystal poly(2,2 -dimethyl-4,4 -dioxyazoxybenzenedodecanedioyl-dj0) (poly[oxy(3-methyl-1,4-phenylene)azoxy 2-methyl-1,4-phenylene)oxy(1,12-dioxo-1,12-dodecanediyl-d2oll) is explored with deuterium NMR. The quadrupol splittings of the spacer methylene segments in the nematic melt of the polymer are reported as a function of the temperature and are contrasted with observations on model compounds solubilized in a nematic solvent. 

Polymers account for about 3—4% of the total butylene consumption and about 30% of nonfuels use. Homopolymerization of butylene isomers is relatively unimportant commercially. Only stereoregular poly(l-butene) [9003-29-6] and a small volume of polyisobutylene [25038-49-7] are produced in this manner. High molecular weight polyisobutylenes have found limited use because they cannot be vulcanized. To overcome this deficiency a butyl mbber copolymer of isobutylene with isoprene has been developed. Low molecular weight viscous liquid polymers of isobutylene are not manufactured because of the high price of purified isobutylene. Copolymerization from relatively inexpensive refinery butane—butylene fractions containing all the butylene isomers yields a range of viscous polymers that satisfy most commercial needs (see OLEFIN POLYMERS ELASTOMERS, SYNTHETIC-BUTYL rubber). 

Spectra have been recorded of the following polymers Poly isobutylene. Schaufele has reported a spectrum of a non-turbid specimen of this material complete with depolarization data (18). Bands at Av - 2919 and 720 cm 1 are clearly polarized and must result from symmetrical modes. Schaufele was also able to show that the short chain hydrocarbon CH3(CH2)12CH3 could be examined satisfactorily but the results were very much sharpened by cooling to liquid air temperatures. Polyisoprene and Polybutadiene. Both of these in the cis form have also been examined at Southampton very recently. The trans isomers gave no spectra due to fluorescence but no interpretation has been attempted as yet. Spectra are shown in Fig. 7 and 8. 

Batteries. Many 7t-conjugated polymers can be reversibly oxidized or reduced. This has led to interest in these materials for charge-storage batteries, since polymers are lightweight compared to metallic electrodes and liquid electrolytes. Research on polymer batteries has focused on the use of polymers as both the electrode and electrolyte. Typical polymer electrolytes are formed from complexes between metal-ion salts and polar polymers such as poly(ethyleneoxide). The conductivity is low at room temperature due to the low mobility of cations through the polymer-matrix, and the batteries work more efficiendy when heated above the glass-transition temperature of the polymer. Advances in the development of polymer electrolytes have included polymers poly(ethylene oxide) intercalated into layered silicates (96). These solid-phase electrolytes exhibit significantly improved conductance at room temperature. 

Scheme 10 Liquid crystalline polymer poly(I7) and its precursors...

Scheme 11 Liquid crystalline crown ether polymer poly(22)...

Scheme 14 Complexation of liquid crystalline crown ether polymers poly(17, 25)...

Non-volatile solvents eliminate the health and environmental risks associated with the use of volatile solvents, but may pose their own risks and separation problems. Several liquid polymers, such as PEG, poly(propylene glycol) (PPG), poly(tetrahydrofuran) (PTHF), Polydimethylsiloxane (PDMS), poly(methylphenyl siloxane) (PMPS), and variations of those with ether or ester end-capping groups, are compared in terms of environmental risk, solvent polarity, and performance as... 

As vehicles for the electropolymerization of benzene to form the conducting polymer poly (p-phenylene).47 Ionic liquids are said to be good alternatives to liquid sulfur dioxide. 

Dishwash tablets have undergone a transformation in the past few years, going from a simple powder or liquid gel, to two-in-one tablets, to three-in-one tablets, to four-in-one tablets, and recently to five-in-one tablets, which were launched in 2005. This latest version comes with three sections sealed inside water soluble compartments made of the - polymer poly (vinyl alcohol). The various ingredients in a dishwash product have to be kept separate to prevent them from reacting chemically with one another. Some of the ingredients can coexist without reacting, such as the surfactants and the enzymes, as they do in laundry detergent powders, and some are most useful if they are released near the end of the wash, such as rinse aids. 

The first reported thermotropic and lyotropic liquid-crystalline poly(aryleneethynylene)s were not parent PPEs, but organometallic derivatives 65 made by the Pd-catalyzed condensation of Vollhardt s diethynyl 64 with diiodobenzenes 46 [45]. The polymers were isolated in good to excellent yields as amorphous tan or red powders with moderate Pn values of... 

Poly sulfide compounds that are compatible with epoxy resins are liquid elastomers at room temperature. The most significant commercial resin of this type is LP-3 from Toray. The predominant product is a mercaptan-terminated liquid polymer (LP) that contains approximately 37% bound sulfur (see Fig. 7.2). It is the high concentration of sulfur linkages that provides these products with their unique chemical properties. A sulfur odor is noticeable during processing, making ventilation important. 

Solid-phase microextraction (SPME) — is a procedure originally developed for sample preconcentration in gas chromatography (GC). In this procedure a small-diameter fused silica optical fiber, coated with a liquid polymer phase such as poly(dimethylsiloxane), is immersed in an aqueous sample solution. The -> analytes partition into the polymer phase and are then thermally desorbed in the GC injector on the column. The same polymer coating is used as a stationary phase of capillary GC columns. The extraction is a non-exhaustive liquid-liquid extraction with the convenience that the organic phase is attached to the fiber. This fiber is contained in a syringe, which protects it and simplifies introduction of the fiber into a GC injector. Both uncoated and coated fibers with films of different GC stationary phases can be used. SPME can be successfully applied to the analysis of volatile chlorinated organic compounds, such as chlorinated organic solvents and substituted benzenes as well as nonvolatile chlorinated biphenyls. 

Regioselective dialkylation of naphthalene is another reaction of considerable interest as 2,6-dialkylnaphthalenes can be oxidised to naphthalene-2,6-dicarboxylic acid, which is used in the synthesis of the commercially valuable polymer, poly(ethylene naphthalenedicarboxylate) (PEN).22 PEN has properties that are generally superior to those of polyethylene terephthalate) (PET) and has become the polymer of choice for a variety of applications such as in films, industrial fibres, packaging, liquid crystalline polymers, coatings, inks and adhesives. However, the high cost of naphthalenedicarboxylic acid has been a major hindrance to widespread application. 

Beret, S. Prausnitz, J. M., "Densities of Liquid Polymers at High Pressure. Pressure-Volume-Temperature Measurementsfor Polyethylene, Polyisobutylene, Poly(vinyl acetate), and Poly(dimethylsiloxane) to 1 kbar," Macromolecules, 8, 536 (1975). 

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