Polyethylene oxide purification

The nonionic surfactant, nonylphenol deca(oxyethylene glycol) monoether, NP-EO10, supplied by Berol Kemi AB, Stenungsund, Sweden, was of technical grade and used without further purification. The main impurity is free polyethylene oxide. Analysis of the sample gave a polyethylene oxide content of = 3% (4). Note, that polyethylene oxide adsorbs on polystyrene latexes ( ), but a monolayer is reached at solution concentrations that are 10 times the concentration required to obtain a monolayer coverage with NP-EO q. The free polyethylene oxide, therefore, is expected to have negligible influence on the adsorption measurements. 

In this section we will describe the results of our angular dependent XPS measurements, XPS (0), which were made on a series of polystyrene (PS)-polyethylene oxide (PEO) diblock (PS-PEO) and triblock (PEO-PS-PEO) copolymers. Table 3 contains the copolymer composition and molecular weight data for the various block copolymers employed in this study. The synthesis, purification and characterization of these materials has been described previously. (H)... 

Fractions of high molecular weight polyethylene oxide were obtained from Union Carbide and used without further purification. They are essentially pure compounds without any contaminating impurities which may affect the high resolution NMR iTieasurements. 

BP3, OC, EHMC, EHS, HMS, OD-PABA, 4-MBC, BM-DBM, IAMC, EHT, DBT BP3, 4-MBC, EHMC, OC, OD-PABA, 4HB, 4DHB, BP1 PMALE with low density polyethylene membranes PT E with in-cell purification with aluminum oxide... 

Starting Materials. Polyethylene, low density (0.92), was obtained from Union Carbide as additive-free pellets. Copper propionate, used only for liquid-phase solubilities, was obtained commercially and used without further purification. All other copper salts were synthesized as follows equal equivalents of Cu(OH)2 CuC03 ( 99+%, ROC/RIC Chemical Corp.) and the appropriate carboxylic acid were stirred in a minimum amount of xylene and heated to 120°C under N2 overnight. After reacting the xylene solution was diluted with additional xylene, reheated, and filtered hot to remove any copper oxides and/or carbonates. The xylene solution was cooled and the resultant precipitate collected by suction filtration and washed with additional xylene and then hexane. Additional recrystallization was done from hexane, isooctane, and/or xylene. In the case of the copper octanoate the solubility in xylene was quite high, so minimum amounts were used and recrystallization was done from hexane. Analyses for copper Cu(C7Hi5C02)2,... 

The experimental techniques used were modifications of those previously described, Styrene (Monsanto Co.), divinylbenzene and trimethylol propane triacrylate (Polysciences Inc.) were freed from inhibitor and residual trace polymer by column chromatography on aluminium oxide. Monomers were used immediately after purification. For the actual grafting runs, low density polyethylene films (thickness, 0.12 mm. Union Carbide) were placed as strips (4 x 2 5 cm) in lightly stoppered pyrex tubes (15 x 2.5 cm) containing styrene/solvent solutions (20 ml) at 20 1°C For irradiation, the tubes were held on a circular rack surrounding a 1200 Ci cobalt-60 source The tubes were positioned such that the surfaces of the film were perpendicular, or near perpendicular, to the plane of the radiation At the completion of the irradiation, the grafted polymer films were removed from the monomer solution and exhaustively extracted in... 

Stobinski L, Lesiak B, Kover L, Toth J, Biniak S, Trykowski G, Judek J (2010) Multiwall carbon nanotubes purification and oxidation by nitric acid studied by the FTIR and electron spectroscopy methods. J Alloy Compd 501 77-84 Sudesh K, Abe H, Doi Y (2000) Synthesis, structure and properties of polyhydroxyalkanoates biological polyesters. Prog Polym Sci 25 1503-1555 Tang W, Santare MH, Advani SG (2003) Melt processing and mechanical property characterization of multi-walled carbon nanotube/high density polyethylene (MWNT/HDPE) composite films. Carbon 41 2779-2785... 

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