Thermal Degradation Behavior of a Poly(n-Butylmethacrylate-Co-Acrylic Acid)/Organobentonite Nanocomposite: Non-Isothermal Decomposition Kinetic Study

The aim of this study is to investigate the effects of a small amount of organomodified bentonite (OBT) on the thermal stability and degradation kinetics of the intercalated poly(n-butylmethacrylate-co-acrylic acid) P(n-BMA-AA) nanocomposite. P(n-BMA-AA)-18 copolymer containing 17.9 mol% of acrylic acid (AA) and P(n-BMA-AA)-17/OBT3 nanocomposite containing 16.7 mol% of AA at 3 mass% of OBT are synthesized via in situ free radical polymerization and characterized. Thermogravimetric analysis (TGA) shows an improvement of the thermal stability of P(n-BMA-AA)-17/OBT3 nanocomposite compared to the pure copolymer. The apparent activation energies E-a of thermal decomposition of the elaborated nanocomposite are higher than those of the virgin copolymer, reflecting the OBT stabilizing effect upon the matrix's decomposition. Besides, the TGA kinetic study reveals that the degradation kinetic of copolymer is well fitted by model F2 (g(a) = (1 - a)(-1) - 1). Whereas, the A1F1 (g(a) = -ln(1 - a)) and R2 (g(a) = 1 - (1 - a)(1/2)) models are found to well represent the experiment for the first and second stages degradation in the nanocomposite.