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On cellulose triacetate

This reaction is utilized by Burrows et al. [70] to photoinitiate grafting of acrylamide, acrylic acid, methacrylamide, and acrylonitrile on cellulose triacetate in acidic aqueous solution. [Pg.257]

All consumer films and professional stock continue to be offered on cellulose triacetate. All its X-ray and micro photographic film is supported on PET. Only Advantix is on PEN. The primary issue is the cost of PEN, which may be why it has not been adopted widely in packaging. Its transport characteristics for bottles is excellent because of its physical characteristics. Its cost is high but a premium price in a premium product is more acceptable than it would be in Kodak s mainstream product range. [Pg.175]

An early generation of composite membranes, developed by Riley, et al. (21), was based on cellulose triacetate (CTA) cast in an ultrathln coat from chloroform on the finely porous surface of a cellulose nitrate/cellulose acetate substrate. These membranes did not reflect a need for a hydrophllic-gel Intermediate layer. Yet, this membrane substrate is much more hydrophilic than the rejecting CTA layer, and high flux as well as high separation were concurrently obtained. This is not the case if the porous substrate is highly hydrophobic. A rejecting layer deposited on such a surface would yield an extremely poor productivity due to the loss of... [Pg.286]

This cycloaddition-reduction-hydrolysis sequence was also used in an approach to butyrolactones related to ribonolactone (71). These compounds are inducing agents of hunger and satiety in mammalians. Here, a subsequent aldol 1,3-diol reduction was used, and the required carboxy function was established by oxidation of the aromatic ring with ruthenium tetroxide. Cycloaddition of benzonitrile oxide to allyl alcohol afforded an enantiomeric mixture of isoxazolines 55 and 56, which were treated with sodium hydride and methyl iodide to achieve separation by chromatography on cellulose triacetate (71). 0-Demethylation, followed by... [Pg.418]

Table 9. Analytical and Semipreparative Separation of Enantiomers on Cellulose Triacetate... Table 9. Analytical and Semipreparative Separation of Enantiomers on Cellulose Triacetate...
Dye carriers, occasionally called dyeing accelerants, are used on cellulose triacetate libers, but have found their greatest use in the dyeing of polyester. [Pg.511]

FIGURE 9 Chromatograms of enantiomeric resolution on cellulose triacetate CSPs. (a) /V-Benzoylalanine methyl ester, with hexane-ethanol (80 20, v/v) as the mobile phase, (b) Benzoin with hexane-2-propanol-water (70 27 3, v/v/v) as the mobile phase, (c) Mandelic acid with ethanol as the mobile phase. (From Ref. 9.)... [Pg.52]

Hesse, G. and Hagel, R. (1973) Complete separation of a racemic mixture by elution chromatography on cellulose triacetate, Chromatographia 6, 277-280. [Pg.319]

Dioxinones Obtained by Resolution or Prepared with a Chiral Auxiliary. 2-Phenyl-4//-1,3-dioxin-4-ones (15) derived from formylacetate or acetoacetate can be readily prepared in enantiopure form by preparative resolution " on cellulose triacetate. These have been used for Michael additions and hydrolysis to long-chain p-hydroxycarboxylic acids, for example the tride-canoic acid (16) from (/ )-(15a). The cuprate adducts formed with the methylphenyldioxinone (i f-flSb) can be hydrogenolyti-cally cleaved directly to p-branched p-hydroxy acids with benzyl protection of the hydroxy functional group see (17) in eq 9. ... [Pg.165]

Other successful determinations of glass transition temperatures by inverse gas chromatography indude those of Perrault et al. 22) on poly(butadiene), Nakamura et al 26) on cellulose triacetate and Cahigaru et id. 27) on poly(viiq l acetate). [Pg.113]

DeVries, Smit and Smith 100) reported heats of adsorption on cellulose triacetate (44.8% acetyl) and diacetate (25% acetyl) using alcdiols and aromatics as solutes. They observed a systematic difference in heats of adsorption for each solute between both polymer stationary phases, indicating a difference in partial molar heats. They discussed their results in terms of nonspecific and hydrogen bonding interactions between the polymers and the solutes. [Pg.138]

Kusumocahyo, S.P., Kanamori, T., Sumaru, K., Aomatsu, S., Matsuyama, H., Teramoto, M., and Shinbo, T., Development of polymer inclusion membranes based on cellulose triacetate Carrier-mediated transport of cerium(III). J. Membr. Sci., 2004, 244 251-257. [Pg.914]

Figure 3. Adsorption isotherms of different gases on cellulose triacetate polymer at 35°C. (Reproduced with permission from ref. 22. Copyright 1988 Academic Press.)... Figure 3. Adsorption isotherms of different gases on cellulose triacetate polymer at 35°C. (Reproduced with permission from ref. 22. Copyright 1988 Academic Press.)...
Blumel et al. [18] measured the isotherms of (+) and(-) hetrazipine (WEB170) on cellulose triacetate, using the perturbation method operated in closed-loop mode to reduce the amount of chemicals needed. The data were satisfactorily modeled with the Langmuir equation. The separation of the enantiomers of a-ionone... [Pg.158]

The helical compounds 198a and 199 were separated into the enantiomers by inclusion chromatography (medium-pressure column chromatography on cellulose triacetate). 200 was enantiomerically enriched (—)-200 was only weakly enrich-... [Pg.62]

The enantiomers of 212 were enriched through inclusion chromatography on cellulose triacetate. They show the rotation values (272) [aJlJs = —57 (CD Ae = —7.9 and +4.1). [Pg.67]

Wolf, R. M., Erancotte, E., Lohmann, D., Quantitative correlation between calculated molecular properties and retention of series of structurally related racemats on cellulose triacetate, J.Chem. Soc., Perkins Trans. II, 1988, 893-901. [Pg.338]

A similar series of tests for the assessment of the dyeing properties of Disperse Dyes on cellulose triacetate has been published J.S.D.C., 1965, 81, 209). [Pg.512]

Photographic emulsions composed of octahedral silver bromide grains were used in these experiments. The average grain size was 0.7 pm, or 0.2 pm. Methanolic solutions of various dyes were added to the emulsions, which were then coated at about 40 mg silver bromide/dm and at about 30 mg gelatin/dm on cellulose triacetate film base. The coated films were subjected to both ESR and sensitometric measurements at room temperature. [Pg.71]

This ketone can be resolved on gram scale into the enantiomers with >99% ee by chromatography on cellulose triacetate. The undesired enantiomer is racemized by treatment with methoxide in methanol. Enantiomerically pure ketone 51-4 is then converted into the bromo ketone 51-5 by cuprate addition and bromination. Heating in DMF closes the dihydrofuran ring to form 51-6. Elaboration of the vinyl sidechain leads to sulfonamide 51-7 which is then submitted to reductive cyclization. In this way 51-9 is generated which gives the anti-tussive (-)-dihydrocodeinone 51-10 in enantiomerically pure form. [Pg.98]

X Chen, H Zou, L Yang, H Wang, O Zhang. Optical resolution of alpha-alkyl phenyl acetonitriles by HPLC on cellulose triacetate chiral stationary phases coated on underivatized silica gel. Chirality 12 599-605, 2000. [Pg.382]

The actual experimental conditions employed range from the use of cultured broths of common microorganisms, through the use of cell-free extracts, to the use of columns of fully immobilized enzymes embedded on cellulose triacetate fibres, and reactions are rapid at 30°. [Pg.24]

If the gel is to be stored or analyzed by densitometry, it should be washed several times after staining, using 7% (V/V) acetic acid. Then the gel is laid on cellulose triacetate and allowed to dry in the air. [Pg.76]


See other pages where On cellulose triacetate is mentioned: [Pg.265]    [Pg.386]    [Pg.389]    [Pg.666]    [Pg.280]    [Pg.457]    [Pg.458]    [Pg.22]    [Pg.49]    [Pg.220]    [Pg.1020]    [Pg.356]    [Pg.68]    [Pg.103]    [Pg.103]    [Pg.110]    [Pg.293]    [Pg.630]    [Pg.630]    [Pg.458]   
See also in sourсe #XX -- [ Pg.62 , Pg.64 , Pg.65 ]




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