Thermal degradation of commercially available organoclays studied by TGA–FTIR (original) (raw)

Thermogravimetry coupled to Fourier transform infrared spectroscopy (TGA/FTIR) has been used to study the thermal decomposition products evolved during the degradation of several commercially available organoclays (Cloisites TM Na + , 10A, 15A, 20A, 25A, 93A and 30B). It was found that the decomposition pattern of the organoclays was different for each sample: Cloisite TM 10A shows three well-defined degradation stages, Cloisite TM 30B only two stages and the Cloisite TM 93A only one weight loss; Cloisites TM 15A, 20A and 25A exhibited a more complex behavior showing one main stage and a shoulder. It was also observed that the onset of the decomposition was different for each type of organoclay, being Cloisite TM 10A the lowest (160 • C) and Cloisite TM 93A the highest (212 • C). FTIR analysis of the evolved products from their non-oxidative thermal degradation showed the release of water, aldehydes, carboxylic acids, aliphatic compounds and, in some cases, aromatic compounds and CO 2 . It is suggested that the degradation of both tallow residue and unexchanged surfactant explain the presence of some products evolved during degradation of organoclays.