PolymersDiffusion-ordered NMR spectroscopy (DOSY) allows for accurate molecular weight calibration and determination that can be corrected for solvent influences. Polystyrene and poly(ethylene glycol) standards have been used to calibrate DOSY diffusion data for a variety of solvents, showing a high ...
It is suitable for polymer materials and can provide accurate molecular weight data. This method can be applied over a wide range of molecular weights and is particularly suitable for high molecular weight polymers. In conclusion, the molecular weight determination of polymers is an important task i...
In 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 universal calibration curve in GPC and the Mark-Houwink-Sakurada equation were also drawn. The comb-like polymer ...
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...
Determination of Molecular Weight Distribution of Polymers by Thermal Field-Flow FractionationBinocular disparityinvariant object recognitionspatial-frequency analysisoptical flowWigner distributionThe Thermal Field-Flow Fractionation method was used to determine average molecular weights for standard polystyrene ...
Molecular Weight DeterminationThe 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 ...
Chain architecture of LDPE as a function of molar mass using size exclusion chromatography and multi-angle laser light scattering (SEC-MALLS) Long chain branching causes a decrease in molecular size and hence in the radius of gyration and the hydrodynamic radius, as compared to polymers having a...
In order to overcome the difficulty of the determination of the molecular weight of a polymer in the low molecular weight region by viscometry using the Mark-Houwink-Sakurada (MHS) equation, we have proposed the Dondos-Benoit relationship []-1 = A 2 + AM -1/2, for a number of polymer...
a range of polymers of varying molecular weight. Such fractions will range from 200,000 to 400,000 inaveragemolecular weight. The electron microscope has permitted measurement of the size of the molecular particles. Size/frequency data can then be converted into a molecular weight distribution ...
rotors, farnesyl-(2-carboxy-2-cyanovinyl)-julolidine (FCVJ), can be used as an active probe for precise determination of the M dependence of η and the entanglement molecular weight of a polymer by using a molecular weight series of poly-(propylene oxide) (PPOX) as model polymers. Our...