A method for labeling the functional groups in polymers has been developed. This method converts the COOH (or OH) groups to a radioactive ester which is easier to characterize by GPC than the parent polymer. The method is more sensitive than classical analysis and gives functionality distribution in addition to total functionality. Applications of the method are given for polymers of acrylic acid and vinyl alcohol and liquid epoxy resin. Radiotracer techniques have been also used to confirm structure of bisphenol A epoxies by using 14C labeled bisphenol A.

The use of gel permeation chromatography (GPC) for the rapid determination of molecular weight distributions of carboxy‐terminated polybutadienes is demonstrated. Whole polymer samples and fractions prepared by elution fractionation were characterized by GPC and viscosity measurements with two different solvents for each method. Variable functionality (COOH group) dependence of the polystyrene gel columns is shown. Thus there is a need to pretest the columns for COOH absorption before use with materials containing carboxylic acid. Effects of sample size and also of carboxy termination as compared with hydrogen termination are discussed. Correlations between tetrahydrofuran and CHCl3 chromatograms are given. As a first approximation the Q factor of 16 is indicated for molecular weight determination from a standard polystyrene calibration in both tetrahydrofuran and CHCl3.