Results 301 to 310 of about 326,825 (346)

Simultaneous determination of polymer average molar mass and molar mass distribution, and concentration of additives by GPC-GC

Journal of Microcolumn Separations, 2000
In this paper, the gel permeation chromatography–gas chromatography (GPC–GC) method was proposed to carry out determination of average molar masses and molar mass distribution of polymers and concentration of additives simultaneously. In this method, after the determination of average molar masses and molar mass distribution by ordinary GPC, a part of ...
Nobuya Kobayashi, Hiromi Arimoto, Yuzuru Nishikawa   +2 more
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Molar mass distribution of diallyl 3,6-endomethylene-1,2,3,4-tetrahydrophthalate prepolymer

Polymer Science U.S.S.R., 1989
Abstract Gel permeation chromatography was used to study the variation in molar mass distribution during benzoyl peroxide initiated polymerization of diallyl 3,6-endomethylene-1,2,3,4-tetrahydrophthalate in benzene solution. Whilst a linear polymer is formed initially, branched chains begin to predominate at higher conversions.
V.I. Kolegov, M.I. Khramushina, V.S. Etlis, M.A. Lysova, I.V. Kotlyarskii, R.V. Kronman, A.B. Bulovyatova   +6 more
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Comparison of different methods for the determination of the molar mass and molar mass distribution of poly(ethylmethylsiloxane)

Macromolecular Chemistry and Physics, 2000
The application of a poly(dimethylsiloxane) (PDMS) calibration curve for size exclusion chromatography (SEC) to poly(ethylmethylsiloxane) (PEMS) leads to molar masses, which are 15–40% higher than expected compared to measurements of the absolute molar mass values.
H. Götz, U. Maschke, T. Wagner, C. Rosenauer, K. Martin, S. Ritz, B. Ewen   +6 more
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Isotactic Polystyrene Reactor Blends with Tailored Bimodal Molar Mass Distribution

Macromolecules, 2013
Reactor blend formation of soluble highly isotactic polystyrene (iPS) enables tailoring of bimodal iPS molar mass distributions containing variable amounts of ultrahigh molar mass iPS (UHMWiPS). A key feature is the facile iPS molar mass control, achieved by homogeneous catalytic styrene polymerization on a MAO-activated titanium bisphenolate catalyst,
Vielhauer, Maximilian, Bodendorfer, Simon, Lutz, Pierre J., Friedrich, Christian, Mülhaupt, Rolf   +4 more
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Determination of molar mass distribution of alkyl polyethylene glycol ethers

Journal of the American Oil Chemists' Society, 1981
AbstractA process based on gas chromatographic separation and on the computerized evaluation of the results has been developed for the determination of the distribution and distribution coefficients of alkyl polyglycol ethers, formed in the competitive, consecutive reaction of fatty alcohol and ethylene oxide.
L. Farkas, J. Morgós, P. Sallay, I. Rusznák, B. Bartha, G. Veress   +5 more
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Molar Masses and Molar Mass Distributions

1984
In synthesizing polymers in vivo and in vitro, molecular homogenous (“monodisperse”) polymers (i.e., those in which every macromolecule has the same molar mass or “molecular weight”) occur only under quite specific conditions. The overwhelming majority of polymer syntheses proceed more or less randomly, and the resulting macromolecular substances have ...
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Influence of Molar Mass Distribution on Thermodynamics of Polymer Systems

1989
For the description and prediction of thermodynamic data, e.g. volumetric and compositional derivatives of thermodynamic functions of state, many theoretical models are available. The Simha-Somcynsky theory can be considered to be very succesful if one is interested in the quantitative description of thermodynamic properties.
Nies, E.L.F., Stroeks, A.A.M.
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Influence of Molar Mass Distribution on the Compatibility of Polymers

Journal of Macromolecular Science, Part A, 1996
Abstract Phase equilibria were calculated by means of a new method (direct minimization of the Gibbs energy of mixing) for polymer blends consisting of monodisperse polymer A and polydisperse polymer B. The results obtained for a Schulz-Flory distribution of B (molecular nonuniformity U = (M w/M n) −1 = 1 and 100 components of model B) agree ...
Sabine Enders, Axel Hinrichs, Roland Horst, B. A. Wolf   +3 more
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Determination of Molar Mass and Molar Mass Distributions

1984
Molar mass determination methods can be classed as absolute, equivalent, or relative. Absolute methods allow the molar mass to be directly calculated from the measured quantities without the need for assumptions concerning the physical and/or chemical structure of the polymers.
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Pearson-type I Distribution Function for Polydisperse Polymer Systems. Molar Mass Distribution^,

Journal of Chemical Information and Computer Sciences, 2003
This paper presents an attractive feature of the distribution function, which uses a relatively simple expression for approximating probability density. The Pearson-type I distribution function is used to represent the molar mass distribution (MMD) function for polymers for which the number average (M(n)), mass average (M(w)), z-average (M(z)), and (z ...
Bogdanić, Grozdana, Jakab, Lajos
openaire   +4 more sources