Preparation and Properties of Inorganic-Organic Hybrids From Vinyland 3-Methacryloxypropyltrimethoxysilane
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between the structure and physical or mechanical properties of free-standing films and coating films.
S(ButO)2
}I•L
-12/HCI)
Fe-tndn
.Tl
MeO- qi- OMe OMe
MeO' SI- OMe OMe
q OR'
VTS
PVTS
R'= H,OMe, Sl PVPS
o (But)2 MeO- Si- OMe OMe
}iOFree-standing films Coating films
O O=~ ABýO
~= 0 Me-
im
HO/HCl
0_
Free-standing films
Coating films
Si- OMe OMe W= H,OKe, Si
MAS
PMPS
S-PMA
Scheme 1 EXPERIMENTAL Radical Polymerization of VTS VTS (24.7 g, 0.167 mol) and t-butyl peroxide were placed in a four-necked flask equipped with a condenser and a stiffer, and then heated to 150 *C for 2 h at a rotation rate of 200 rpm. The reaction mixture was cooled with an ice bath for 1 h. After removal of the solvents under reduced pressure followed by extraction with hexane-methanol, polyvinyltrimethoxysilane (PVTS) was isolated as a viscous liquid by drying the hexane insoluble part under reduced pressure. Radical Polymerization of MAS MAS (6.2 g, 0.025 mol), t-butyl peroxide, and ethyl lactate were placed in a four-necked flask equipped with a condenser and a stirrer, and then heated to 150 °C for 2 h at a rotation rate of 200 rpm. The reaction mixture was cooled with an ice bath for 1 h. After removal of the solvents poly(3under reduced pressure followed by extraction with hexane-methanol, methacryloxypropyltrimethoxysilane) (S-PMA) was isolated as a viscous liquid by drying the hexane insoluble part under reduced pressure. Hydrolysis of PVTS PVTS (12.35 g, 0.084 mol) and methanol (7 ml) were placed in a four-necked flask equipped with a stirrer, a nitrogen inlet tube and a nitrogen outlet tube, and then cooled with an ice bath followed by addition of water and 6 N hydrochloric acid. The mixture was stirred at 0 °C for 10 min, another 10 min at room temperature and at 70 'C for 3 h at the rotation rate of 150 rpm under a nitrogen flow rate of 360 mil/min. Solvents were removed under reduced pressure to provide a highly viscous liquid of PVPS.
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Preparation of free-standing gel films and coating films PVPS free-standing gel films were prepared by casting a 20 wt% acetone-methanol (VN=1) solution of PVPS on a polymethylpentene shale at 80 oC for several days. PMPS gel films were prepared by adding hydrochloric acid to a 20 wt% acetone-methanol (VN=I) solution of S-PMA and then heating at 80 'C for several days. The PVPS and PMPS coating films were prepared by dip-coating of various substrates in a 20 wt% acetone-methanol (VN= 1) solution of PVPS and S-PMA followed by heating at 80 *C for 24 h and then at 100 'C for several hours. RESULTS AND DISCUSSION Table I summarizes the results of the hydrolysis of PVTS. T°, T', , and T3 denote the unit structures of siloxane. Their ratio was estimated on each signal area in 29Si NMR spectra. S-PMA was hydrolyzed rapidly to provide a gel by uncontrollable hydrolysis. The molecular weight and siloxane structure unit T2 increased with the increase of molar ratio of water to PVTS indicating the progress of the hydrolysis. Mw of PVTS 6800c) 10900W,
Table I H20/Si 0.15 0.17 0.
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