Kinetics of degradation of organic additives used in the ceramic industry

Abstract The kinetics of thermal degradation of three additives to ceramic mixes, namely sodium methyl carboxy cellulose (CMC), Corn Starch and Gum Arabic were studied. FTIR analysis disclosed the functional groups present in these materials, while thermal analysis was carried out at four heating rates (5, 10, 15 and 20 K.min −1 ) in nitrogen flow. In all cases one main DTG peak was observed that was subjected to kinetic analysis using two model-based methods: the Coats–Redfern and Criado’s master plots techniques. Also, the variation of activation energy with conversion was studied by two iso-conversional methods, namely KAS and Friedman methods, and the results were compared to previous studies. The most probable degradation mechanisms for CMC were F1 or A2. For Corn Starch, first-order reaction (F1) turned out to be the most probable kinetic mechanism, whereas the degradation of Gum Arabic followed an R3 reaction mechanism. The possibility of using any of these additives in glazed ceramic tiles is also discussed.