Polymer Testing Lab : Gel Permeation Chromatography

Gel permeation chromatography (GPC) involves the use of size exclusion chromatography (SEC) to separate polymer analytes on the basis of size. This practice provides useful information pertaining to the polymer's molecular weight and molecular weight distribution.

Two important things to remember about GPC: Separation takes place based upon polymer size in solution, not molecular weight, and polymer size in solution depends upon solvent and temperature.

Possible reasons why customers request GPC Analysis of Polymers include:

• Interest in Molecular Weight M_w Which Can Have an Effect On Tensile Properties and Impact Resistance

• Interest in Molecular Number M_n Which Can Have an Effect On Brittleness, Flow Properties, and Compression Set

• Interest in M_z Which Can Have an Effect On Elongation and Flexibility

• Interest in M_z+1 Which is Related to Die Swell

• Interest in Molecular Weight Distribution

• Interest in Polymer Dispersity