Organic-inorganic hybrid materials. V. Dynamics and degradation of poly(methyl methacrylate) silica hybrids

Abstract

Poly(methyl methacrylate)–silica hybrid materials (PMMA–SiO2) were prepared by in situ polycondensation of alkoxysilane in the presence of trialkoxysilane‐functional PMMA. Infrared, differential scanning calorimetry, 29Si and 13C nuclear magnetic resonance spectroscopy, and thermogravimetric analysis were used to study the PMMA–SiO2 hybrids. The effects of the content and kind of the alkoxysilane on the dynamics and stability of the PMMA–SiO2 hybrids were investigated in this study.The dynamics of SiO2within hybrids were investigated with 29Si–1H cross‐polarization. The spin‐diffusion path length was on a nanometer scale estimated with the spin–lattice relaxation time in the rotating frame (T italicH1ρ). The apparent activation energies for the degradation of the hybrids under air and nitrogen were evaluated by the van Krevelen method. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1972–1980, 2000

Hybrid thin films derived from UV-curable acrylate-modified waterborne polyurethane and monodispersed colloidal silica

“…The spectra show six peaks at -50 to -51, -57 to -59, -65 to -67, -91 to -93, -100 to -102, and -109 to -111 ppm (Figure 6A), which are assigned to T 1 , T 2 , T 3 , Q 2 , Q 3 , and Q 4 , respectively. The positions of these peaks are similar to previous reports [29,30]. These peaks correspond to the chemical structures shown in Figure 6B.…”

Effect of ZnO on the Thermal Degradation Behavior of Poly(Methyl Methacrylate) Nanocomposites

“…Among inorganic fillers added to PMMA, silica was the most widely investigated. [10][11][12][13][14] The thermal degradation of such composites was a prime areas of investigation. It was shown that the addition of silica into PMMA improves thermal stability of the composites.…”

Effect of concentrations of plasticizers on the sol-gel properties developed from alkoxides precursors

“…Polymerization or condensation degree of the trifunctional %Dc(T) and tetrafunctional %Dc(Q) species was calculated using the equations (Equations 3 and 4) [22,24] : ( )…”

“…The total fractions of trifunctional and tetrafunctional species were calculated as follows (Equations 5 and 6) [22,24] : The total degree of condensation corresponds to (Equation 7) [22,24] :…”