Further studies in gel permeation chromatography.

[摘要] Gel Permeation Chromatography has become an established method for rapid molecular weight and dispersion characterisation of polymers. The method is based on the separation of the polymer into an infinite number of narrow fractions by permeation of the polymer solution through the porous crosslinked polystyrene gel. Fundamental studies have been carried out into the packing techniques relating to pressure and flow rate variables for the porous gel. It has been found that high constant pressure gives higher packing efficiency, but it is not as reproducible as the constant flow rate method. A study has also been made of the care and treatment of the solvent, tetrathydrofuran, with particular interest to the peroxide concentration increase, and the effect of the solvent on brass tubing over prolonged exposure. Sample concentration effects have also been studied, paying particular interest to the low molecular weight tail which is often observed with concentrated samples. A study of different polymer concentrations, but with the same relative viscosity was also made, with particular interest in the elution volume and theoretical plate count for the polymer. A new type of gel has been developed, which enables an aerogel to stabilise a xerogel, and hence the gel so produced has xerogel elution properties, but aerogel packing properties. The use of thin layer chromatography to characterise gels has also been considered. A scanning electron microscope has been used to study the morphologogy of the new gels, and also the supramolecular structure of freeze dried polystyrene in benzene solution.

[发布机构] University:University of Birmingham;Department:School of Chemistry

[关键词] Q Science;QD Chemistry