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Molecular weights and molecular-weight distributions from ultracentrifugation of nonideal solutions
Biophysical Chemistry, 1976Ultracentrifugation, membrane osmometry and capillary viscometry experiments have been performed on two dextran samples, which have molecular-weight distributions (MWDs) similar to those of dextrans used as blood plasma extenders. The manufacturer reported values of Mn and MW, determined by end group analysis and by light scattering, respectively.
P J, Wan, E T, Adams
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Journal of Polymer Science Part A-2: Polymer Physics, 1968
AbstractA method has been developed for determining the molecular weight distribution of a polymer sample from the sedimentation–diffusion equilibrium data for a solution under pseudo‐ideal conditions. From some theoretical examples it appears that the method works well and that the molecular weight distribution can be determined with a reasonable ...
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AbstractA method has been developed for determining the molecular weight distribution of a polymer sample from the sedimentation–diffusion equilibrium data for a solution under pseudo‐ideal conditions. From some theoretical examples it appears that the method works well and that the molecular weight distribution can be determined with a reasonable ...
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Determination of Molecular Weights and Molecular Weight Distribution of Polyacrylamides
SPE Annual Technical Conference and Exhibition, 1984ABSTRACT A high-performance, size-exclusion chromatography procedure has been developed for determining molecular weights and molecular weight distributions of polyacrylamides. The procedure can be applied to dry or emulsion polyacrylamides. Virgin polymers and polymers passed through Berea sandstone cores can be analyzed. The analytical
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Measurement of the Molecular Weight Distribution of Debranched Starch
Biomacromolecules, 2005Combining molecular weight distribution (MWD) data for linear chains of debranched starch from capillary electrophoresis and from size exclusion chromatography (SEC) with detection by differential refractive index and by multi-angle laser light scattering has enabled Mark-Houwink parameters to be determined for linear starch chains.
Castro, J. V. +3 more
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Determination of Molecular Weight and Molecular-Weight Distribution
1977Molecular-weight determination methods can be classed as absolute, equivalent, or relative. Absolute methods allow the molecular weight to be calculated directly from the measured quantities; a knowledge of the physical and chemical structure of the molecules is not required.
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Molecular weight distribution of a polyester
Journal of Applied Polymer Science, 1964AbstractCombined solvent composition and column temperature gradients were employed to effect the efficient fractionation of a polyester into several molecular weight fractions in about 16 hr. Mixtures of methyl ethyl ketone and cyclohexane were used as eluents for the fractionation which was conducted in a copper column packed with glass beads.
Charles M. Hansen, Glenn A. Sather
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Journal of Chromatography A, 1971
Abstract A simple micro-method for the determination of molecular weights of chondroitin sulphate has been developed. Columns of Sephadex G-200 and Sepharose 6B were calibrated with fractions of chondroitin sulphate, the molecular weights of which had been determined by independent methods.
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Abstract A simple micro-method for the determination of molecular weights of chondroitin sulphate has been developed. Columns of Sephadex G-200 and Sepharose 6B were calibrated with fractions of chondroitin sulphate, the molecular weights of which had been determined by independent methods.
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Determination of molecular weight dependences and characterization of molecular weight distributions
European Polymer Journal, 1982Abstract Molecular weight dependences of the square of the radius of gyration as well as of the coefficients of diffusion and friction of monodisperse polystyrenes in toluene at 20°C are determined experimentally. For this purpose, the z-averages of these quantities and M w as determined by light scattering were subjected to the polydispersity ...
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Ratios of average molecular weights and molecular weight distributions in polymers
Journal of Polymer Science: Polymer Physics Edition, 1979AbstractIf Mmin and Mmax are lower and upper bounds, respectively, to the molecular weights of different molecular weight species contained in a polymer, the weight‐average to number‐average molecular weight ratio Mw/Mn cannot exceed (1 + Mmax/Mmin)2/(4Mmax/Mmin).
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The molecular weight distribution of oligomers
Polymer, 1982Abstract It is shown that the relation P w P n = 2 or the nonuniformity U = 1 is only a limiting case for high degrees of polymerization, is no more valid for oligomers. Two new relations are derived, one including and one excluding monomers. For the oligomer part of cationically produced polystyrenes the second relation is in good
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