Jun 20, 1980
Journal of Chromatography A
Abstract A sample of acrylonitrile-styrene copolymer was fractionated into ten portions by using analytical scale size-exclusion chromatography and the composition of the copolymer fractions was determined by using pyrolysis gas chromatography. A 0.12-ml volume of each fraction was collected in a platinum boat and the copolymer on the boat was pyrolyzed at 700°C after the removal of solvent. The amount of copolymer pyrolyzed at a time ranged from 0.004 mg to 0.022 mg. The copolymer fractions have an average acrylonitrile content of 24%, the composition ranges from 21% to 30%, with the acrylonitrile content decreasing with increasing molecular weight. These data are in fair agreement with those determined by a dual-detector method, using ultra-violet and differential refractive index detectors. This system can be applied to the determination of both distributions, molecular weight and composition, of copolymers for which a dual-detector method is inadequate.