6533b7d6fe1ef96bd12664d4

RESEARCH PRODUCT

Estimation of Number-Average Molecular Weights of Copolymers by Gel Permeation Chromatography−Light Scattering

Wolfgang RadkePeter F. W. SimonAxel H. E. Müller

subject

Polymers and PlasticsElutionScatteringOrganic ChemistryDispersityAnalytical chemistryLight scatteringInorganic ChemistryGel permeation chromatographychemistry.chemical_compoundchemistryMaterials ChemistryMolar mass distributionPolystyreneMethyl methacrylate

description

The true number-average molecular weight, Mn, of copolymers is obtained by GPC coupled with a light-scattering detector even if the composition and therefore the refractive index increment varies with elution volume, provided slices taken are monodisperse with respect to molecular weight and composition. In contrast, only an apparent weight-average molecular weight, can be obtained by the conventional GPC−light scattering combination, even for a perfect chromatographic resolution. The errors in Mn associated with nonhomogeneous slices are estimated. Experimental data with mixtures of linear polystyrene and poly(methyl methacrylate) confirm these estimations and indicate that the error in Mn is less than 10% for the system under investigation.

https://doi.org/10.1021/ma9516495