Über die Konzentrationsabhängigkeit der Zähigkeit bei organischen Hochpolymeren

Heß, Kurt; Philippoff, W.

doi:10.1002/cber.19370700411

Cited by 43 publications

(3 citation statements)

References 37 publications

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“…To reduce the time required to make measurements, solutions containing 0.1 g (rather than 0.25 g) of nitrocellulose per 100 ml of acetone were used. To render the results comparable to the findings published by others, fluidities were calculated for solutions having a concentration of 0.25 g per 100 ml, by means of Hess and Philipoff's modification [14] of Baker's equation:…”

Section: Methodsmentioning

confidence: 72%

Oxidation of cellulose: The reaction of cellulose with periodic acid

Rutherford¹,

Minor²,

Martin³

et al. 1942

J. RES. NATL. BUR. STAN.

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An investigation has been made of the mode of attack of cellulose by periodic acid during the early stages of the oxidation (that is, oxidation of approximately 1 percent of tb~ glucose residues). Under these conditions, it is shown that the reaction is confined to oxidation of the secondary hydroxyl groups to aldehyde groups, and results in a rupture in the carbon chain between carbon atoms 2 and 3 of the glucose unit. In accordance with this mechanism it is shown that two moles of aldehyde groups are produced for each mole of oxidant consumed. The aldehyde groups of the periodic acid-oxycellulose can readily be converted to carboxyl groups, titration of which provides an independent check on the content of the former.Periodic acid-oxycellulose is characterized by its susceptibility to further attack by alkaline solutions. The a lkali-sensitivity of these materials, as measured by solubility in hot dilute sodium hydroxide and by cuprammonium fluidity, appears to be proportional to the content of aldehyde groups. However, upon conversion of all of the a ldehyde groups to carboxyl groups, the alkali-lability practically disappears. The results suggest that the sensitivity of periodic acid-oxycellulose to alkali does not depend solely on the rupture of the glucose ring between carbon atoms 2 and 3, but is related to the specific instability towards alkali of the dialdehyde formed during the oxidation. CONTENTS Page

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Section: Methodsmentioning

confidence: 72%

Oxidation of cellulose: The reaction of cellulose with periodic acid

Rutherford¹,

Minor²,

Martin³

et al. 1942

J. RES. NATL. BUR. STAN.

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“…Hess and Philippoff (12) obtained very good agreements of the value of [tj] of technical collodion in butyl acetate solutions, in the wide range of concentrations from 0.05 to 15.00 weight per cent, except that the values for concentrations of 1 per cent and less were about 4 per cent higher than those for higher concentrations. More recently Philippoff and Kriiger (20) found this equation to give good reproducibility of [17] in viscose solutions, varying in concentration from 0.02 to 11.99 per cent, except that here again the values of [ ] for concentrations of 1 per cent or less averaged higher, and in this case about 17 per cent.…”

Section: Methods For Approximating Vomentioning

confidence: 90%

“…First, Philippoff's equation may be partially evaluated: c (-VSr-HW-l• 16 (1.735 V 1 /F, -1) (12) where Fs is the fluidity of the solution and F" that of the solvent (equals 82.25 rhes). The intrinsic viscosity having been computed the degree of polymerization, DP, and molecular weight, M, become, respectively DP = 260 [ ] Thus, a cellulose in 0.5 per cent cuprammonium solution giving a fluidity of 0.80 rhe at a velocity gradient of 500 sec.-1 would have an intrinsic viscosity of 12.6, a degree of polymerization of 3280, and a molecular weight of 531,000.…”

Section: Calculation Of Molecular Weight Of Cellulosementioning

confidence: 99%

Role of Velocity Gradient in Determining Cuprammonium Fluidity of Cellulose

Conrad

1941

Ind. Eng. Chem. Anal. Ed.

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Estimation of viscosities of mixed polymer solutions

Rudin

Hoegy

Johnston

1972

J of Applied Polymer Sci

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SynopsisA semiempirical model for estimation of viscosities of concentrated polymer solutions' can be applied to mixtures of polymers in a common solvent. The data required for estimation of mixture viscosity are: solvent viscosity, polymer molecular weight, density, concentration, and intrinsic viscosity in the particular solvent. Calculated and experimental viscosities agree to within a few per cent for the relatively nonpolar systems for which comparative data are available. The model does not appear to be adequate for mixtures in which there are extensive hydrogen-bonding interactions.Results of the new model are equivalent to those of an empirical equation2 reported to be effective for fairly concentrated binary polymer mixtures.Specific interactions between polymeric solutes can be conveniently assessed by comparing measured mixture viscosity to that calculated from the model presented. It is not clear, however, that such assessments have any fundamental significance, since the interactions which are calculated depend on the assumptions inherent in the estimation of the "ideal'' mixture viscosity. The same reservations apply to other models which have been proposed for this purpose.

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Über die Konzentrationsabhängigkeit der Zähigkeit bei organischen Hochpolymeren

Cited by 43 publications

References 37 publications

Oxidation of cellulose: The reaction of cellulose with periodic acid

Oxidation of cellulose: The reaction of cellulose with periodic acid

Role of Velocity Gradient in Determining Cuprammonium Fluidity of Cellulose

Estimation of viscosities of mixed polymer solutions

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