A rapid technique for measuring copolymer composition as a function of molecular weight using gel permeation chromatography and infrared detection

A gel permeation chromatograph using an infrared spectrometer detector is described. Operation in a stop‐and‐go fashion permits rapid determination of copolymer composition as a function of molecular weight. A broad distribution copolymer, poly(vinyl chloride–co–vinyl stearate), showed marked compositional changes with molecular weight. The changes observed are not in agreement with those predicted from reactivity ratios. Copyright © 1975 John Wiley & Sons, Inc.