GPC/SEC Basic Theory 2. What is GPC?

2. GPC 

(1) Definition

① Gel Permeation Chromatography is a physical separation mechanism where larger components elute before smaller ones based on the hydrodynamic volume size of the analytes.

☞ Big Ones Come Out First

② Unlike other chromatography that relies on chemical separation, GPC depends on the physical characteristics (pore size) of the packing material and the dimension relationship of the substance to be separated.

③ Permeation Process: Large molecules quickly pass through as they cannot enter the pores of the porous gel, while smaller molecules can enter the pores and therefore elute more slowly.

④ Molecules that pass through the column faster have a higher molecular weight.

(2) Application

① Molecular Weight Distribution (MWD)

② Molecular Weight (MW), Polydispersity (PD) → correlation with distribution and physical properties

• Mn is related to brittleness, flow properties, compression set.
• Mw is related to strength properties, (tensile, impact resistance).
• Mz is related to elongation and flexibility.