The novel modeling approach for the study of thermal degradation of PMMA/nanooxide systems

• Main Authors: Mirjana Jovicic, Oskar Bera, Katalin Meszaros Szecsenyi, Predrag Kojic, Jaroslava Budinski-Simendic, Dragan Govedarica, Jelena Pavličević
• Format: Article
• Language: English
• Published: Society of Chemists and Technologists of Macedonia 2019-05-01
• Series: Macedonian Journal of Chemistry and Chemical Engineering
• Subjects: pmma, metal oxide nanoparticles, mathematical modeling, thermal stability, thermal decomposition kinetics
• Online Access: https://mjcce.org.mk/index.php/MJCCE/article/view/1685

PMMA (poly(methyl methacrylate)) nanocomposites differing in their nature, size, and surface area were prepared containing one volume percent of silica, alumina or titania. These samples and pure PMMA were prepared in order to analyze how the presence of nanooxides affects the thermal stability and degradation kinetics of the materials. A detailed study of thermal degradation and thermal changes was performed by Simultaneous Thermogravimetry and Differential Scanning Calorimetry (SDT). The proposed mathematical model, including all three heating rates in one minimizing function, well fitted all TGA data obtained with a very high coefficient of correlation. This enabled an assessment of four decomposition steps of the PMMA samples and a calculation of their activation energies and individual contributions to total mass loss. The addition of the largest nanoparticles (titania) caused the highest activation energy for each DTG stage of the PMMA/nanooxide systems. The enhancement of head-to-head H–H bonding strength was achieved by addition of alumina and titania. The influence of the size and nature of nanoparticles on the glass transition temperature of prepared PMMA systems was also determined.