Structure-molecular weight relationships of synthetic polymers
In this application note, the structural distribution of some common polymers are compared using the Mark-Houwink plot. The data are all generated using the advanced OMNISEC multi-detector GPC/SEC system
sponsored by Malvern Panalytical
Introduction
The physical properties and behavior of polymers depends strongly on the properties of the polymer molecules themselves. This in turn means that the polymer properties will also have an impact on the properties of finished products made from or containing polymers. The molecular weight and molecular weight distribution, molecular size, intrinsic viscosity and structure all affect how the polymer material will behave. The most common tool used to investigate these aspects of synthetic polymers is gel-permeation or size-exclusion chromatography (GPC/SEC).
The principle of GPC involves separating the sample as it travels through a porous but inert chromatography column matrix. While smaller molecules penetrate the pores more deeply, larger molecules are excluded and thus travel through the column faster. The result is a separation based on hydrodynamic volume. The basic data is simply a concentration profile of the size-separated sample but by using a multi-detector GPC system that combines light scattering, refractive index (RI), ultraviolet (UV) and intrinsic viscosity detectors, a large amount of information about a sample can be determined simultaneously.
