SPECIES-SPECIFIC ISOCONVERSION EFFECTIVE ACTIVATION-ENERGIES DERIVED BY THERMOGRAVIMETRY MASS-SPECTROMETRY

The use of species-specific mass spectral ion signal temperature profi les for generating isoconversion effective activation energies by the Flynn-Wall-Ozawa method is described. Effective activation energies de rived from mass-loss and mass-spectral results obtained from TG-MS ana lyses of calcium oxalate monohydrate and poly(vinyl butyral) thermal d ecompositions are compared. Although effective activation energies der ived from mass-loss data may suggest changes in overall reaction proce sses, species-specific effective activation energy variations provide information regarding selected reaction mechanisms. (C) 1998 Elsevier Science B.V.