ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
A modified high-performance liquid chromatographic method for the analysis of the molecular weight distribution of poly(tetramethylene ether) glycol (PTMEG) is described. The weight percentage of the polymer homologues, up to a degree of polymerization X of 79, can be determined. This covers about 93 wt.-% of the material with number-average molecular weight M̄n = 1000, but only 65 wt.-% of that with M̄n = 2000. Direct calculation of the means M̄n, M̄w, and M̄z from these percentages leads to erroneous results because of the neglect of the summands with X 〉 79. Therefore, a curve fit is performed and M̄n, M̄w, and M̄z are calculated from the fitting parameters. From the known molecular weight distribution functions, Wesslau's and Kubin's function yielded the best fit. The results of this method are compared with those of gel permeation chromatography, viscosimetric measurements, supercritical fluid chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and evaporative light scattering detector methods. The scope and the limitations of this method are discussed.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1997.021980719
Permalink
