Thermal Degradation of Poly(vinylbutyral)/Ceramic Composites: A Kinetic Approach

Kinetic models for the thermal degradation of poly(vinylbutyral) PVB/Al2O3 and PVB/AlN composites, based on weight loss and evolved gas analysis (EGA), are presented. TG (sample weight loss) and FT-IR (mixture gas spectra) data were measured to elucidate the kinetic models using isothermal and nonisothermal approaches. The mixture IR spectra at each time or temperature were resolved using a least-mean-square (LMS) algorithm to obtain the dynamic information for each major volatile product formed during the degradation process. The kinetic results using isothermal and nonisothermal approaches showed excellent agreement. Activation energies of PVB thermal degradation are ∼300 kJ/mol in nitrogen and ∼200 kJ/mol in air for pure PVB and ∼100 kJ/mol for PVB/Al2O3 and PVB/AlN in nitrogen. The polymer residues at different isothermal treatments were subjected to DRIFTS spectra, and the carbon content of the residual samples was analyzed using a Leco analyzer.