A review of gel permeation chromatography: Part 2

Bellens has reported the study of several types of alkyd resin using a Waters Associates chromatograph equipped with a duplicate set of four columns covering a porosity range of 0.485 to 105 nm and eluted with THF at ambient temperature. Automatic sample injection was employed and, during a four‐hour fractionation process, the eluent from the sample set of columns was monitored by a differential refractometer using the other set as reference. The detector signal was fed to the Y‐axis of an X‐Y recorder, on which the X‐axis was used to display eluent volume information. A generalised GPC curve is presented in which the author identifies the zones attributable to solvent, non‐polymerised materials, oligomers and polymers and shows the pseudomaxima that arise from the four individual columns. Molecular sizes are quoted for fatty acids (15 Å), phthalic‐glycerol monoester (15 Å), diphthalate glycerol monoester (26 Å), monoglycerides (34 Å), phthalic monoester monoglyceride (37 Å), diglycerides (51 Å) and triglycerides (67 Å), whilst the GPC traces for most alkyds are shown to have a peak in their molecular size distributions between 75 and 120 Å.