GPC (gel permeation chromatography) or SEC (size exclusion chromatography) is a method for determining the average molecular weights and molecular weight distributions in polymer samples.
The separation is based on the different hydrodynamic volume which the molecularly dispersed molecules occupy in the corresponding solvent.
In addition to the distribution curve and the differently weighted average molecular weights Mn , Mw and Mz as well as the polydispersity, percentages of molecular fractions with a certain size can also be determined and branching analyses can be performed.
Technical equipment
Our systems are equipped with different detectors (RI, UV-Vis, viscosity and light scattering), which allow both a determination of relative molecular weights (conventional calibration) and a determination of absolute values (universal calibration, evaluation via light scattering).
Among others, we have experience with the measurement of:
- Cellulose in DMAc/LiCl
- Polyacrylonitrile (PAN) in DMAc/LiCl
- Melamine resins in DMAc/LiCl
- Polyurethanes (PU) in DMF/LiBr
- Chitosan in H2O/acetate buffer
- Polycarbonate (PC) in THF
Publications
- Kosan, Birgit; Römhild, Katrin; Meister, Frank: „Possibilities for Efficiency Improvement of the Lyocell Process – Effects of Molecular Mass and Molecular Mass Distribution” in: Lenzinger Berichte 93, 2017, S. 47-52. https://www.lenzing.com/index.php?type=88245&tx_filedownloads_file%5bfileName%5d=fileadmin/content/PDF/03_Forschung_u_Entwicklung/Lenzinger_Berichte_93_2017.pdf
Kosan, Birgit; Schwikal, Katrin; Meister, Frank: “Effects of pre-treatment and dissolution conditions for improved solution and processing properties of cellulose in ionic liquids" in: Lenzinger Berichte 90, 2012, 76-84 https://www.lenzing.com/index.php?type=88245&tx_filedownloads_file%5bfileName%5d=fileadmin/content/PDF/03_Forschung_u_Entwicklung/Lenzinger_Berichte_90_2012.pdf