molecular weight determinationpolymersmonomer sequenceDetermination of molecular weights of polymers by 1H-NMR spectroscopy is discussed. A brief survey of application of NMR; both 1H and 14C, in the analysis of
Molecular WeightOsmometryGel-Permeation ChromatographyViscometryMark–Houwink–Sakurada EquationUniversal Calibration CurveIn this note, the MW determination of a comb-like polymer was carried out by GPC and by membrane osmometry. It was found that the MW by GPC is smaller than by osmometry. The ...
efficiency can be reached e.g., by reducing the thickness of the channel by a factor of two.Results presented in this paper confirm the prospects offered by the Field-Flow Fractionation method for determinations of molecular weights, and eventually also molecular weight distributions for polymers. ...
When the solvent is poor for one of the polymers, limitations arise due to the secondary separation effects. Furthermore, a GPC method is proposed for the determination of the Dondos-Benot constants (A1 A2) which must be known for the above-mentioned calibration. This method uses either two...
The molecular weight of a polymeric or biological material usually has a direct effect on its mechanical properties, thermal behavior, and viscosity characteristics. There are a variety of analytical techniques used to characterize molecular weight in polymers, each providing useful information about the...
30, No. 5, pp 439-443 (1998) Direct Determination of Molecular Weight Distribution by Size Exclusion Chromatography with 750 MHz 1H NMR Detection (On-Line SEC-NMR) Koichi UTE, Ryo NIIMI, Shin-ya HONGO, and Koichi HATADAt Department of Chemistry, Graduate School of Engineering Science, Osaka...
A large number of polymers are semicrystalline, the degree of crystallinity can be investigated using DSC. A simple method for doing this is described in this article. The crysatllinity of a polymer can be estimated from its melting behavior and the melt
[51,52] applied this method for the study of water desorption process from hydrophilic polymers and have found correlation of the obtained results with those found by the isopiestic method [53]. However, it is noteworthy that this method of dynamic desorption porosimetry is rather difficult both ...
Theoretical or Mathematical/ molecular weight determinationpolymersrheology/ molar weight distributionrheological measurementsmolecular analysisDoi-Edwardsentangled polymeric liquidsgeneralized exponential distributiondiscriminationidentification/ A4660 Rheology of fluids and pastes A3620F Molecular weights of macromolecules...
All the experimental data indicate that the number-average molecular weights (Mn) determined either by SEC or VPO are always different Nevertheless such discrepancies are less pronounced using the new calibration curve instead of either the conventional polystyrene standards or other polymers such as ...