RESUMO
Polyacrylamide (PAM) and its derivatives are the most commercially available water-soluble polymers and are frequently used for the production of clay-polymer composites. The characterization of their thermal behavior and decomposition was carried out mainly under reduced conditions by using N2, He or Ar gas flow. The object of this study was to investigate the thermal decomposition of cationic (PAMS,τ40Cl), nonionic (PAM°S), and anionic (NaPAMS,τ40) polyacrylamide under synthetic air (SynA) in detail using a thermogravimetry/differential scanning calorimetry (TG/DSC) system connected to a quadrupole mass spectrometer (MS). MS data indicated the release of NH3, CH4 and NO together with H2O, CO2 and NO2 during decomposition. The gas release differed between the three polymers. Stoichiometric calculations showed that PAMS,τ40Cl and PAM°S decomposed completely, while NaPAMS,τ40 decomposed only partially and the Na present for charge balancing remained in the form of Na2O. The thermal decomposition of PAMS,τ40Cl, PAM°S and NaPAMS,τ40 under SynA occurred via pyrolysis and oxidation reactions.