341
2011). T
H 8 is slightly soluble in chloroform, cyclohexane, hexane and methylene
chloride, but insoluble in acetonitrile and water (Hybrid Plastics 2008). The structures of the geometric isomers of T
H 12 and T
H 14 were determined by X-ray and the
29
Si-NMR (Agaskar et al. 1987).
A
‘spherosilicate’:
1,3,5,7,9,11,13,15-octakis(dimethylsiloxy)pentacyclo[9.5.1.1
3,9
.1
5,15
.1
7,13
]octasiloxane ((HMe 2 SiOSiO 1.5 ) 8 , Q 8 M
H 8 ) is a colourless crystalline compound (Husemann and Greber 1962; Hoebbel and Wieker 1971; Hasegawa
and Motojima 1992; Moran et al. 1993; Majoros et al. 1997; Provatas et al. 1998;
Hasegawa et al. 2003; Laine 2005; Soh et al. 2007), soluble in many solvents: chloroform, diethyl ether (Xiao et al. 2007), hexane, tetrahydrofuran (THF), toluene
(Hybrid Plastics 2008; Wahab et al. 2008; Perrin et al. 2011), but insoluble in methanol and water (do Carmo et al. 2004). The synthesis of crystalline Q 8 M
H 8 has
been carried out in two steps (Husemann and Greber 1962; Hoebbel and Wieker
1971; Hasegawa and Motojima 1992, Hasegawa 1993; Hasegawa et al. 2003;
Majoros et al. 1997; Provatas et al. 1998; Zhang et al. 2000). In the reaction of tetramethylammonium hydroxide (Me 4 NOH) with TEOS was prepared octakis
(tetramethylammonium) octasilsesquioxane, and then reacted with DMCS (Provatas
et al. 1998; Zhang et al. 2000; Xiao et al. 2007; Laine et al. 2008). The yields of
Q 8 M
H 8 were improved up to 85–91% (Perrin et al. 2011; Dutkiewicz et al. 2011).
A four-membered ring silsesquioxane (PhSiO 1.5 ) 8 (MeHSiO) 2 (‘double-deckershaped-silsesquioxane’) containing two Si-H end groups was synthesized with a
20% yield in the reaction of MDS with a precursor which was obtained by the
condensation reaction of PhSi(OMe) 3 with sodium hydroxide (NaOH) (Seino et al.
2006a). Similarly, 5,11,14,17-tetra(hydrodimethylsiloxy)octaphenylcyclooctasilsesquioxane was prepared from tetra(sodiosilanolate) precursor and DMCS
(Ahsan et al. 2007; Wu et al. 2007).
Ladder POSSs containing T
H
and MeSiO 1.5 units can be synthesized by hydrolysis
of poly(carbosilazane)s, which have been prepared by the condensation of HSiCl 3 and
MeSiCl 3 with ethylenediamine or p-phenylenediamine (Li et al. 1999; Wan et al. 1998;
Cao et al. 2000). Hydrosiloxane and hydrosilsesquioxane resins were obtained in high
yields from trifunctional alkyl- and hydrochlorosilanes or hydroalkoxysilanes, with
alcohols and water, in non-polar hydrocarbon solvents, in the presence of solid ionexchange resins (Hacker et al., 1999). Zhao and Feng (2003) synthesized branched
Si-H multifunctional silicone resins by the hydrolytic polycondensation of MDS with
DDS, TMCS and methyltriethoxysilane (MeSi(OEt) 3 , MTES) or phenyltriethoxysilane (PhSi(OEt) 3 ). New siloxane-silsesquioxane copolymers (soluble in THF) were
recently prepared by the dehydrocondensation of T
H
8 with Ph 2 Si(OH) 2 , tetraphenylisiloxanediol or oligodimethylsiloxane-α,ω-diols in the presence of diethylhydroxyamine, followed by trimethylsilylation reaction (Gunji et al. 2010).
The thermosetting silicone resins, containing hydrosiloxane and mixed silsesquioxane units of the general formula (Ph 2 SiO) a (HSiO 3/2 ) b (RSiO 3/2 ) c , were obtained by
the hydrolytic polycondensation of Ph 2 Si(OH) 2 (or cyclohexyltrichlorosilane) with
HSiCl 3 or in reactions of Ph 2 Si(OH) 2 with phenyltrichlorosilane (PhSiCl 3 ), HSiCl 3
(or MDS) and MeSiCl 3 , with C 5 H 5 N, in ether, at −78 °C. These resins, soluble in
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications
2011). T
H 8 is slightly soluble in chloroform, cyclohexane, hexane and methylene
chloride, but insoluble in acetonitrile and water (Hybrid Plastics 2008). The structures of the geometric isomers of T
H 12 and T
H 14 were determined by X-ray and the
29
Si-NMR (Agaskar et al. 1987).
A
‘spherosilicate’:
1,3,5,7,9,11,13,15-octakis(dimethylsiloxy)pentacyclo[9.5.1.1
3,9
.1
5,15
.1
7,13
]octasiloxane ((HMe 2 SiOSiO 1.5 ) 8 , Q 8 M
H 8 ) is a colourless crystalline compound (Husemann and Greber 1962; Hoebbel and Wieker 1971; Hasegawa
and Motojima 1992; Moran et al. 1993; Majoros et al. 1997; Provatas et al. 1998;
Hasegawa et al. 2003; Laine 2005; Soh et al. 2007), soluble in many solvents: chloroform, diethyl ether (Xiao et al. 2007), hexane, tetrahydrofuran (THF), toluene
(Hybrid Plastics 2008; Wahab et al. 2008; Perrin et al. 2011), but insoluble in methanol and water (do Carmo et al. 2004). The synthesis of crystalline Q 8 M
H 8 has
been carried out in two steps (Husemann and Greber 1962; Hoebbel and Wieker
1971; Hasegawa and Motojima 1992, Hasegawa 1993; Hasegawa et al. 2003;
Majoros et al. 1997; Provatas et al. 1998; Zhang et al. 2000). In the reaction of tetramethylammonium hydroxide (Me 4 NOH) with TEOS was prepared octakis
(tetramethylammonium) octasilsesquioxane, and then reacted with DMCS (Provatas
et al. 1998; Zhang et al. 2000; Xiao et al. 2007; Laine et al. 2008). The yields of
Q 8 M
H 8 were improved up to 85–91% (Perrin et al. 2011; Dutkiewicz et al. 2011).
A four-membered ring silsesquioxane (PhSiO 1.5 ) 8 (MeHSiO) 2 (‘double-deckershaped-silsesquioxane’) containing two Si-H end groups was synthesized with a
20% yield in the reaction of MDS with a precursor which was obtained by the
condensation reaction of PhSi(OMe) 3 with sodium hydroxide (NaOH) (Seino et al.
2006a). Similarly, 5,11,14,17-tetra(hydrodimethylsiloxy)octaphenylcyclooctasilsesquioxane was prepared from tetra(sodiosilanolate) precursor and DMCS
(Ahsan et al. 2007; Wu et al. 2007).
Ladder POSSs containing T
H
and MeSiO 1.5 units can be synthesized by hydrolysis
of poly(carbosilazane)s, which have been prepared by the condensation of HSiCl 3 and
MeSiCl 3 with ethylenediamine or p-phenylenediamine (Li et al. 1999; Wan et al. 1998;
Cao et al. 2000). Hydrosiloxane and hydrosilsesquioxane resins were obtained in high
yields from trifunctional alkyl- and hydrochlorosilanes or hydroalkoxysilanes, with
alcohols and water, in non-polar hydrocarbon solvents, in the presence of solid ionexchange resins (Hacker et al., 1999). Zhao and Feng (2003) synthesized branched
Si-H multifunctional silicone resins by the hydrolytic polycondensation of MDS with
DDS, TMCS and methyltriethoxysilane (MeSi(OEt) 3 , MTES) or phenyltriethoxysilane (PhSi(OEt) 3 ). New siloxane-silsesquioxane copolymers (soluble in THF) were
recently prepared by the dehydrocondensation of T
H
8 with Ph 2 Si(OH) 2 , tetraphenylisiloxanediol or oligodimethylsiloxane-α,ω-diols in the presence of diethylhydroxyamine, followed by trimethylsilylation reaction (Gunji et al. 2010).
The thermosetting silicone resins, containing hydrosiloxane and mixed silsesquioxane units of the general formula (Ph 2 SiO) a (HSiO 3/2 ) b (RSiO 3/2 ) c , were obtained by
the hydrolytic polycondensation of Ph 2 Si(OH) 2 (or cyclohexyltrichlorosilane) with
HSiCl 3 or in reactions of Ph 2 Si(OH) 2 with phenyltrichlorosilane (PhSiCl 3 ), HSiCl 3
(or MDS) and MeSiCl 3 , with C 5 H 5 N, in ether, at −78 °C. These resins, soluble in
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications