QUANTIFICATION OF END-GROUPS IN ANIONICALLY POLYMERIZED POLY(METHYL METHACRYLATE)S BY PYROLYSIS-GAS CHROMATOGRAPHY

End groups in anionically polymerized standard poly(methyl methacrylat e)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 wer e determined by pyrolysis-gas chromatography (Py-GC). The characterist ic fragments reflecting the end groups on the pyrogram of the PMMAs we re identified by comparison with those of a radically polymerized PMMA together with the mass spectra of the characteristic peaks on the res ulting pyrograms taken by a gas chromatograph-mass spectrometer (GC-MS ) system. Concentrations of the end groups determined from their relat ive peak intensities were interpreted in terms of M-n and then compare d with their reference values from the manufactures and those estimate d by H-1-NMR. By this method, direct determination of the end groups w as possible even for PMMA with M-n = 10(6) without using any standard polymer samples.