GPC-SEC is an important tool for the analysis of polymers. It provides molecular weight data and molecular weight distribution curves which are needed to characterize a polymer with regard to differences in properties. GPC-SEC is mainly used for samples with a molecular weight above 2000 although it is also in use for oligomer separations. Due to a special calibration procedure using a linear elution volume on the x-axis versus a logarithmic molecular weight on the y-axis, the demands on the instrumentation are very stringent.
This document provides an overview of Gel Permeation Chromatography (GPC), also known as Size Exclusion Chromatography (SEC), as a tool for analyzing polymers based on molecular size. It details the separation mechanism where larger molecules elute first, followed by smaller ones, and explains how molecular weight averages and distributions are calculated to characterize polymer properties. The text highlights that GPC-SEC is essential for samples with molecular weights above 2000 and can handle weights up to several millions.
| Minimum molecular weight for analysis | above 2000 |
|---|---|
| Maximum molecular weight capability | several millions |
| Flow precision requirement | < 0.1 % |
| Column temperature precision requirement | + 0.15 °C |
Components are separated on the basis of size, with large molecules eluting first.
Tetrahydrofuran (THF) is the most frequently used organic solvent.