Compositional analysis of acrylic acid-ethyl acrylate-ethyl methacrylate terpolymers by pyrolysis gas chromatography

A method for the compositional analysis of acrylic acid (AA)-ethyl acrylate (EA)-ethyl methacrylate (EMA) terpolymers by pyrolysis gas chromatography (PyGC) is described. Twelve samples, in which the contents of the AA unit are less than 20 mol %, are used for the experiments. Pyrolysis is performed at 590°C using a Curie point pyrolyzer. The EA/EMA ratio of samples can be determined by the previously proposed method {this journal, 33, 153 (1984)}. But when the AA monomer peak can not be detected clearly in the pyrogram, then another method not using the AA monomer peak is required for the compositional analysis. The EA/EMA ratios and EA monomer/dimer ratios in the pyrogram vary with the contents of monomer units, P1 (AA), P1(EA) and P1(EMA) in the samples, respectively. Thus the value of P1 (AA), P1 (EA) and P1(EMA) can be obtained by multiple regression analysis from the EA/EMA ratios and EA monomer/dimer ratios in the pyrogram. By the application of this proposed method, the composition of the AA-EA-EMA terporymers can be determined easily.