The Eeffect of Length of GPC Columns on Resolution of Molecular Weight Distribution in Low Molecular Weight Samples

GPC is a high performance liquid chromatography technique for separation of components based on their molecular size in a solut. It is a method widely used currently for determiningthe molecular size and molecular weight distribution of high polymers. It is also known as size exclusion chromatography(SEC) or gel filtration chromatography (GFC)[1]. There is a distribution of pore sizes within the stationary phase such that the small molecules can enter most of the pores and aretherefore retained the longest, while the larger molecules enter fewer pores and are retained a shorter time period. SEC can beused to calculate Mn, Mw, Mz, PDI, molecular weight distribution, and determine solvent condition, linear or branchpolymer etc[2]. In determination of molecular weight of polymers and resins, select of best column with optimum length, particle and pore size is critical. In this study the effectof length in GPC columns on resolution in low molecular weight samples were cheked. For this purpose at first themolecular weghit of unknown resins by 3 PLgel columns that their length were 300 mm with 10μm particle size and different pore sizes in series were calculated. Then thiscolumns were replaced with another one with 3μm particle size and mixed bed pore size and the tests were repeated.