End group analysis estimates the molecular weight of polymers by measuring the functional groups at the end of the polymer chain. The method relies on the chemical changes resulting from the reaction of a specific group at the end of the polymer chain to determine their number and derive the m...
The Thermal Field-Flow Fractionation method was used to determine average molecular weights for standard polystyrene samples with narrow distribution whose molecular weight ranged from 3600 to 867000. An effective calibration method was proposed and verified, and through the use of this method ...
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...
The weighted mean value of the two measurement results was taken as the molecular weight of the polyethylene glycol. 展开 关键词: Experimental/ chromatography light scattering polymers refractive index/ molecular weight determination polyethylene glycol chromatography multiangle laser light scattering acid-...
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 ...
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...
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...
以下是ISO16014-2:2019ENPlastics—Determinationofaveragemolecularweightandmolecularweightdistributionofpolymersusingsize-exclusionchromatography—Part2:Universalcalibrationmethod的详细步骤: 1.准备样品:提供足够数量的聚合物流体样品,以确保分析的准确性。 2.校准设备:使用标准物质对分析设备进行校准,以确保设备的准确性和...
The molecular dynamics of polymers have been studied through measurements of such properties as (tracer) diffusivity (D) and (zero-shear) viscosity (η) in relation to the number-average molecular weight (M) of the polymer. These measure-ments can be compared with established theories, for exam...
Determination of Molecular Weight and Size of Ultrahigh Molecular Weight Polymers Using Thermal Field-Flow Fractionation and Light Scattering Thermal field-flow fractionation was used to characterize ultrahigh molecular weight poly(methyl methacrylate) (PMMA) with a light-scattering detector. The influence ...