Organic-inorganic hybrid materials Part 9: Dynamics and stability of PMMA modified aluminum-EAA complex

Poly(methyl methacrylate) (PMMA) containing aluminum-ethyl acetoacetate (EA A) [M5-Al(OBus)(EAA)(2)] was obtained from trialkoxysilane-functional poly( methyl methacrylate) and ethyl acetoacetate modified aluminum sec-butoxide via the sol-gel method. Infrared (IR), C-13 nuclear magnetic resonance (NMR ) spectroscopy, and thermogravimetric analysis (TGA) were used to analyze t he structures and properties of the hybrids with various proportions of PMM A. The effects of the PMMA content on the dynamics and stability of the M5- Al(OBus)(EAA)(2) hybrids were investigated in this study. The 1H spin-diffu sion path length of the hybrids was in a nanometer scale as estimated from the spin-lattice relaxation time in a rotating frame (T-1 rho(H)). The appa rent activation energies (E-a), evaluated by van Krevelens method, of the M 5-Al(OBus)(EAA)(2) in thermo-oxidative degradation for random scission of E AA segments decreased roughly with increasing PMMA content. (C) 2001 Elsevi er Science B.V. All rights reserved.