Jm. Yang et al., ORGANIC-INORGANIC HYBRID SOL-GEL MATERIALS .1. PREPARATION AND CHARACTERIZATION, Die Angewandte makromolekulare Chemie, 251, 1997, pp. 49-60
Three organic-inorganic hybrid materials have been prepared by incorpo
rating poly(styrene-co-methyl methacrylate) (poly(St-co-MMA)), poly(me
thyl methacrylate) (PMMA), and polystyrene (PS) structure units covale
ntly into the SiO2 glass network via the sol-gel approach. The polymer
precursors were synthesized by free-radical copolymerization of styre
ne and/or methyl methacrylate with 3-(trimethoxysilyl)propyl methacryl
ate (MSMA) to obtain the poly(St-co-MMA-co-MSMA) copolymer (molar rati
o St/MMA/MSMA = 30/48/22), poly(MMA-co-MSMA) copolymer (molar ratio MM
A/MSMA = 76/24), and poly(St-co-MSMA) copolymer (molar ratio St/MSMA =
69/31) with glass transition temperatures at about 67 degrees C, 68 d
egrees C, and 61 degrees C, respectively. The characteristics and prop
erties of the copolymers were characterized by H-1 NMR, Fourier-transf
orm infrared spectroscopy (FTIR), gel-permeation chromatography (GPC),
elemental analysis, differential scanning calorimetry (DSC), and ther
mogravimetric analysis (TGA). The copolymers were then hydrolysed and
co-condensated with tetraethyl orthosilicate (TEOS) in tetrahydrofuran
at room temperature to afford monolithic poly(St-co-MMA)-SiO2, PMMA-S
iO2, and PS-SiO2 hybrid sol-gel materials having SiO2 contents of 16-8
4 wt.-%. The thermal properties of the hybrid materials were character
ized by TGA and DSC.