Quantification of end groups in anionically polymerized poly(methyl methacrylate)s by pyrolysis gas chromatography

End groups in anionically polymerized standard poly(methyl methacrylate)s (PMMAs) in the range of number average molecular weight (M-n) = 2.0 x 10(4) to 1.3 x 10(6) with narrow molecular weight distribution were determined by pyrolysis-gas chromatography (Py-GC). The characteristic fragments reflecting the end groups on the pyrogram of the PMMAs were identified by comparison with those of a radically polymerized PMMA together with the mass spectra of the characteristic peaks on the resulting pyrograms taken by a gas chromatograph-mass spectrometer (GC-MS) system. Concentrations of the end groups determined from their relative peak intensities were interpreted in terms of M-n and then compared with their reference values from the manufactures and those estimated by H-1-NMR. By this method, direct determination of the end groups was possible even for PMMA with M-n = 10(6) without using any standard polymer samples.