Liquid Adsorption Chromatography (LAC)

Arkema Analytical Solutions offers strong expertise in liquid adsorption chromatography (LAC), otherwise known as gradient polymer elution chromatography (GPEC), in particular for the characterization of acrylates, methacrylates and styrene copolymers.

As the structure of a polymer becomes more complex its characterization can present unique challenges.  For example, spectroscopic techniques provide only average values of composition for copolymers, not detailed composition distributions.  For such systems, LAC/GPEC, a polymer chromatographic mode relying on the differential affinities between polymers, solvents and columns, is extremely powerful.  Precipitation/redissolution and adsorption/desorption mechanisms control the separation of fractions, providing detailed information about the chemical composition of the material under study.

The LAC/GPEC method is typically applied to:

• Characterize the homogeneity of a copolymer composition distribution
• Distinguish between copolymers and blends
• Deformulate complex polymeric systems