Copolymer composition as a function of molecular weight and the effect of conversion on this relationship

The copolymer compositions as a function of molecular weight for three poly(styrene‐co‐vinyl stearate) copolymers of widely varying conversion were determined. A combined gel permeation chromatography–infrared spectroscopy method was used. Theoretical changes in copolymer composition were calculated using reactivity ratios. Comparison of the calculated and observed changes in copolymer composition as a function of molecular weight showed qualitative agreement. However, the observed changes in composition were significantly larger than those calculated. Copyright © 1976 John Wiley & Sons, Inc.