Effects of inorganic components on the structure and thermo-oxidative degradation of PMMA modified metal alkoxide-EAA complex

Poly(methyl methacrylate) (PMMA) modified titanium and zirconium n-butoxide-ethyl acetoacetate (EAA) complex [M5-Ti(OBun)(2)(EAA)(2) and M5-Zr(OBun)(2)(EAA)(2)] were obtained from trialkoxysilane-functional PMMA and EAA modified titanium and zirconium alkoxide via the sol-gel method. Infrared (IR), C-13 nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA) were used to analyze the structures and properties of the hybrids with various proportions of metal oxide species. The effect of the complex of metal oxides and EAA ligands on structure and thermo-oxidative degradation of the M5-Ti(OBun)(2)(EAA)(2) and M5-Zr(OBun)(2)(EAA)(2) hybrids were investigated in this study. The H-1 spin-diffusion path length of the hybrids was in a nanometer scale as estimated from the spin-lattice relaxation time in a rotating frame, (T-1rho(H)). The apparent activation energies (E-a), evaluated by van Krevelen's method, for random scission of PMMA segments in hybrids decreased with increasing metal oxide content. (C) 2002 Elsevier Science B.V. All rights reserved.