Molecular weight distribution of block copolymers by gel permeation chromatography

1972 ◽  
Vol 25 (9) ◽  
pp. 1869 ◽  
Author(s):  
JR Urwin ◽  
M Girolamo
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Gel Permeation Chromatography ◽  
Elution Volume ◽  
Unperturbed Dimensions ◽  
Molecular Weight Distributions ◽  
Normal Probability ◽  
Weight Distributions ◽  
Scattering Measurements ◽  
Gel Permeation

Molecular weight distributions for block copolymers of polystyrene and polyisoprene have been determined by gel permeation chromatography for a series of well characterized polymers. Universal calibration curves from [η]M against elution volume and by plots of unperturbed dimensions (ro2)� against elution volume have been constructed and examined. Normal-probability curves have been used to calculate the heterogeneity ratio MW/MN and the results compared with values from light scattering measurements and from osmometry.

Structural studies of oligosilanes produced by catalytic dehydrogenative coupling of primary organosilanes

1987 ◽  
Vol 65 (8) ◽  
pp. 1804-1809 ◽  
Author(s):  
C. Aitken ◽  
J. F. Harrod ◽  
U. S. Gill
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Gel Permeation Chromatography ◽  
Structural Studies ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Dehydrogenative Coupling ◽  
Weight Distributions ◽  
Gel Permeation ◽  
End Groups

The structures of some poly(organosilylenes), [Formula: see text] (R = Ph, p-tolyl, n-hexyl, and benzyl), produced by catalytic dehydrogenative coupling of primary silanes have been studied by infrared, nuclear magnetic resonance, and mass spectroscopies. These results, combined with data on molecular weights and molecular weight distributions from vapour pressure osmometry and gel permeation chromatography, lead to the conclusion that the polymers are linear and have SiH2R end groups. The polymers all have degrees of polymerization of ca. 10 and very narrow molecular weight dipersions. Some possible features of the mechanism that gives rise to this behaviour are discussed.

Molecular Weight Distributions of Elastomers—Comparison of Gel Permeation Chromatography with Other Techniques

1965 ◽  
Vol 38 (4) ◽  
pp. 823-831 ◽  
Author(s):  
Leon W. Gamble ◽  
Lowell Westerman ◽  
Ebnest A. Knipp
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Gel Permeation Chromatography ◽  
Molecular Weights ◽  
The Past ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Gel Permeation ◽  
Polymer Fractionation

Abstract During the past decade interest in polymer fractionation for evaluating molecular weight distribution has increased. New polymers, such as polypropylene, high density polyethylene and many others have been subjected to extensive characterization, but some older polymers, including natural rubber have not. In recent years column fractionation has received a great deal of attention; a review has been made by Schneider. Most of the techniques of polymer fractionation, such as precipitation from solution and column fractionation, are quite lengthy and require days or even weeks to complete. A more rapid method for molecular weight distribution has been the goal of polymer chemists for years. The most promising of the rapid methods are turbidimetric and gel permeation chromatography by which analysis is accomplished in a few hours. This paper discusses application of gel permeation chromatography to fractionation of elastomers. In addition this technique is compared with data from column fractionation, light scattering and osmometry. Some of the assumed factors used in converting gel permeation data into molecular weights are in error. But by calibration of the gel permeation chromatograph with classical methods reliable data can be obtained.

Use of gel-permeation chromatography for the study of molecular weight distributions of thermo-plastic polyurethanes

1976 ◽  
Vol 18 (9) ◽  
pp. 2447-2450 ◽  
Author(s):  
I.A. Vakhtina ◽  
T. Bettger ◽  
A.P. Andreyev ◽  
O.S. Novozhilova ◽  
O.G. Tarakanov
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Gel Permeation
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