Gel Permeation Chromatography (GPC)

The most widely practiced chromatographic mode applied to the characterization of polymers is gel permeation chromatography (GPC), also known as size exclusion chromatography (SEC), which provides molecular weight distribution information.  Separation of different polymer weight fractions is achieved through differential elution from a column as a function of the polymer coil sizes in solution.  The molecular weight is calculated by comparison with the elution times of a set of narrow polymer standards.

Arkema Analytical Solutions GPC capabilities cover a range of solvent systems that are suitable for a wide variety of polymer chemistries:  aqueous, tetrahydrofuran (THF), methylene chloride and dimethyl sulfoxide (DMSO).  We routinely analyze crystalline polymers such as polyvinylidene fluoride (PVDF), polyamide (PA), polyethylene terephthalate (PET) and polyactic acid (PLA), as well as other materials.  Our detector technologies include UV (photodiode array) and differential refractometric index (DRI), as well as evaporative light scattering (ELSD).

Typical applications of GPC include:

• Determination of molecular weight averages (Mw, Mn) and polydispersity index (PDI)
• Measurement of molecular weight distribution and cumulative fractions
• Deformulation of complex polymeric systems
• Evaluation of composition distribution through comparison of UV and refractive index data