Standard Test Method for Determination of Weight-Average Molecular Weight of Polymers by Light Scattering

Importancia y uso:

4.1 The weight-average molecular weight is a fundamental structure parameter of polymers, which is related to many physical properties of the bulk material, such as its rheological behavior. In addition, knowledge of the weight-average molecular weight, together with knowledge of the number-average molecular weight from osmometry, provides a useful measure of the breadth of the molecular-weight distribution.

4.2 Other important uses of information on the weight-average molecular weight are correlation with dilute-solution or melt-viscosity measurements and calibration of molecular-weight standards for use in liquid-exclusion (gel-permeation) chromatography.

4.3 To the extent that the light-scattering photometer is appropriately calibrated, light scattering is an absolute method and is therefore be applied to nonionic homopolymers that have not previously been synthesized or studied.

Subcomité:

D20.70

Referida por:

F2150-19, F0561-19

Volúmen:

08.02

Número ICS:

83.080.01 (Plastics in general)

Palabras clave:

light scattering; polymers; weight-average molecular weight ;