Thermal degradation of poly [3‐dimethyl (acryloyloxyethyl) ammonium propanesulfonate]

Thermodegradation of poly[3‐dimethyl(acryloyloxyethyl)am‐monium propanesulfonate], [poly(DAAPS)], was investigated under nitrogen and air atmospheres at various heating rates. When calculating kinetic parameters, such as the activation energy, the preexponential factor and the reaction order, Ozawa's method was applied. Thermodegradation of such polymers occurs in two stages in a nitrogen atmosphere and in three stages in air. These phenomena were the same as with poly(DMAPS). Larger sample weights produce a larger temperature interval (δT) and weight loss (δW). The glass transition temperature (Tg ) and melting point (Tm ) of poly(DAAPS) are lower than for poly(DMAPS), which contains a methyl group in the α‐carbon position. The heat stability of the poly(DAAPS) is lower than that of the poly(DMAPS). The kinetic order of degradation is determined to be unity, in both nitrogen and air atmospheres. The direct pyrolysis mass spectra of such polymers show the two degradation sections. The polymer is mainly destroyed at the side chain at the lower temperature section, and at the main chain at the higher temperature section. From pyrolysis gas chromatography – mass spectra, the major volatile products of isothermal decomposition are carbon dioxide, ethylene, and propene.