367
hydrosilylation of allylamine with PMHS, catalyzed by PtO 2 , followed by reaction
of the copolysiloxane with glucosyl isothiocyanate (Zhou et al. 2004).
New crosslinked poly[(methylsiloxane)-co-(oxymethylene)] copolymers were
synthesized by the cationic ROP of D
H 4 and 1,3,5-trioxane with anhydrous perchloric acid at 70 °C. These new copolymers were white or glassy crystals. Their degree
of crosslinking increased with a higher concentration of the MeHSiO units in the
copolymers (Rodríguez-Baeza et al. 1997).
The properties of PMHS were also modified by IPN formation or self-organizing
ultra-thin layers (Sun et al. 1996; Boileau et al. 1998). Biodegradable multiblock
copolymers were prepared by the hydrosilylation of poly(lactic acid) (PLA) or
allyl-end poly(α-hydroxyacid)s with M
H 2 D n (Bachari et al. 1995).
Two new silicone derivatives bearing a 2,2,6,6-tetramethylpiperidine-N-oxyl
(TEMPO) radical moiety were synthesized by Pt or Rh-catalyzed hydrosilylation
from PMHS with 4-allyl-2,2,6,6-tetramethylpiperidine-N-oxyl ether or alcoholysis
reaction with 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and (Bu 4 N) 2 PtCl 6 ,
[Rh(cod) 2 ]BF 4 (cod = 1,5-cyclooctadiene, nbd = norbornadiene), [Rh(nbd) 2 ]BF 4 ,
[RhCl(cod)] 2 , [RhCl(nbd)] 2 , K 2 PtCl 6 , Pt 2 [(ViSiMe 2 ) 2 O] 3 and RhCl(PPh 3 ) were used
as catalysts. Due to the charge-discharge properties these new silicone materials
could be applied as the next-generation active material for rechargeable batteries
(Suguro et al. 2009).
Linear polysiloxanes with cyclohexyl-substituted octasilsesquioxane and octyl
side groups were prepared by the subsequent hydrosilylation of poly(ethylhydrosiloxane) with 1-allyl-2,3,4,5,6,7,8-heptacyclohexyl(octaasilsesquioxane)
(T
allyl
T
R 7 , R = C 6 H 11 ) and 1-octene using the catalyst Pt 2 [(ViSiMe 2 ) 2 O] 3 . They were
used for the manufacture of free-standing films by the casting method (Ryu
et al. 2010).
Octasilsesquioxanes with linear and branched alkyl substituents were prepared
in high yield by Pt-catalyzed hydrosilylation of alkenes with Q 8 M
H 8 . The derivatives
with n-alkyl chains from C3 to C6 crystallized below 0 °C, while the derivatives
with longer n-alkyl chains (C7 and C8) formed amorphous glasses with a T g around
−100 °C. The melting points for the iso-hexyl and iso-heptyl POSS derivatives were
found above RT, and the iso-pentyl POSS derivative was liquid at 25 °C.
Thermogravimetric analysis (TGA) showed a negative effect of the branching of the
alkyl chain on the thermostability in air atmosphere (Perrin et al. 2011).
14.6.2 Liquid-Crystalline Derivatives from PMHS
Liquid crystals (LCs) are a very important class of modern materials. They exhibit
unique and extraordinary properties due to regions of highly ordered structures in
both solid and liquid phases (Shibaev and Boiko 2009, Shibaev and Bobrovsky, 2017,
Shibaev 2016). LC polysiloxanes are frequently prepared by hydrosilylation routes
from H-siloxanes of different structures (cyclic, linear, star and silsesquioxane
(cubic, ladder or double-decker)) and a variety of mesogens having end olefinic
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications
hydrosilylation of allylamine with PMHS, catalyzed by PtO 2 , followed by reaction
of the copolysiloxane with glucosyl isothiocyanate (Zhou et al. 2004).
New crosslinked poly[(methylsiloxane)-co-(oxymethylene)] copolymers were
synthesized by the cationic ROP of D
H 4 and 1,3,5-trioxane with anhydrous perchloric acid at 70 °C. These new copolymers were white or glassy crystals. Their degree
of crosslinking increased with a higher concentration of the MeHSiO units in the
copolymers (Rodríguez-Baeza et al. 1997).
The properties of PMHS were also modified by IPN formation or self-organizing
ultra-thin layers (Sun et al. 1996; Boileau et al. 1998). Biodegradable multiblock
copolymers were prepared by the hydrosilylation of poly(lactic acid) (PLA) or
allyl-end poly(α-hydroxyacid)s with M
H 2 D n (Bachari et al. 1995).
Two new silicone derivatives bearing a 2,2,6,6-tetramethylpiperidine-N-oxyl
(TEMPO) radical moiety were synthesized by Pt or Rh-catalyzed hydrosilylation
from PMHS with 4-allyl-2,2,6,6-tetramethylpiperidine-N-oxyl ether or alcoholysis
reaction with 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and (Bu 4 N) 2 PtCl 6 ,
[Rh(cod) 2 ]BF 4 (cod = 1,5-cyclooctadiene, nbd = norbornadiene), [Rh(nbd) 2 ]BF 4 ,
[RhCl(cod)] 2 , [RhCl(nbd)] 2 , K 2 PtCl 6 , Pt 2 [(ViSiMe 2 ) 2 O] 3 and RhCl(PPh 3 ) were used
as catalysts. Due to the charge-discharge properties these new silicone materials
could be applied as the next-generation active material for rechargeable batteries
(Suguro et al. 2009).
Linear polysiloxanes with cyclohexyl-substituted octasilsesquioxane and octyl
side groups were prepared by the subsequent hydrosilylation of poly(ethylhydrosiloxane) with 1-allyl-2,3,4,5,6,7,8-heptacyclohexyl(octaasilsesquioxane)
(T
allyl
T
R 7 , R = C 6 H 11 ) and 1-octene using the catalyst Pt 2 [(ViSiMe 2 ) 2 O] 3 . They were
used for the manufacture of free-standing films by the casting method (Ryu
et al. 2010).
Octasilsesquioxanes with linear and branched alkyl substituents were prepared
in high yield by Pt-catalyzed hydrosilylation of alkenes with Q 8 M
H 8 . The derivatives
with n-alkyl chains from C3 to C6 crystallized below 0 °C, while the derivatives
with longer n-alkyl chains (C7 and C8) formed amorphous glasses with a T g around
−100 °C. The melting points for the iso-hexyl and iso-heptyl POSS derivatives were
found above RT, and the iso-pentyl POSS derivative was liquid at 25 °C.
Thermogravimetric analysis (TGA) showed a negative effect of the branching of the
alkyl chain on the thermostability in air atmosphere (Perrin et al. 2011).
14.6.2 Liquid-Crystalline Derivatives from PMHS
Liquid crystals (LCs) are a very important class of modern materials. They exhibit
unique and extraordinary properties due to regions of highly ordered structures in
both solid and liquid phases (Shibaev and Boiko 2009, Shibaev and Bobrovsky, 2017,
Shibaev 2016). LC polysiloxanes are frequently prepared by hydrosilylation routes
from H-siloxanes of different structures (cyclic, linear, star and silsesquioxane
(cubic, ladder or double-decker)) and a variety of mesogens having end olefinic
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications