## Abstract It is one of the key issues to develop powerful fractionating method to increase the identification of the lowโabundance phosphopeptides. In this study, a semiโonline 2โD LC separation strategy based on threeโstep fractionation of the enriched peptides on strong anionโexchange trap colu
Column fractionation of polymers. IV. Large-scale polyester column fractionation
โ Scribed by Manfred J. R. Cantow; Roger S. Porter; Julian F. Johnson
- Publisher
- John Wiley and Sons
- Year
- 1964
- Tongue
- English
- Weight
- 338 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0021-8995
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โฆ Synopsis
A small-scale fractionation of 9 g. and a large-scale fractionation of 90 g. of a polyester were carried out. The polymer was prepared by condensation of isophthalic acid, maleic anhydride, and propylene glycol in the mole ratio 1 : 2: 3. Results from the two fractionations were in good agreement despite different fractionation conditions. By proton magnetic resonance measurements the fractions were found to have nearly constant chemical compositions. The Huggins' constant and the Staudinger relation for this polyester were determined from data on fractions in chloroform a t 30ยฐC. Integral and differential molecular weight distributions as well as various molecular weight averages for the polyester were obtained by a computer program. The fractionation data were applied to several popular distribution correlations. The experimental distribution was found to be in good agreement with that expected from the theory of polycondensation kinetics.
๐ SIMILAR VOLUMES
## Three amorphous homopolymers were fractionated by the column elutiontemperature gradient technique. The efficiency of the molecular-weight separations was determined by gel permeation chromatography. Three column-packing techniques were investigated. The most efficient method entailed prelimina
Gel permeation chromatography produces a type of differential molecular weight distribution directly and rapidly. Conversion of these data to conventional molecular weight distributions and plots of distributions is time-consuming. A computer program is described to perform these operations readily.