351
(Scheme 14.2) (Chauhan et al. 2000). The active catalyst has been reused few times
(Chauhan et al. 2003).
By alcoholysis of PMHS with aliphatic alcohols (n-PrOH, i-PrOH, t-BuOH),
glycidol and aromatic and heteroaromatic substituted carbinols, in the presence of
RhCl(PPh 3 ) 3 (Wilkinson’s catalyst), new linear polysiloxanes with pendant grafts
have been prepared with high yields (Chauhan et al. 2001). The alcoholysis of
PMHS with hydroxyl derivatives of crown ethers gives poly(methylalkoxy-crown
ether)siloxanes, which could be used as new neutral carrier-type ion sensors
(Chauhan and Boudjouk 1999). Similarly, polythioethers have been prepared in
high yields, in reactions of PMHS and D
H 4 with thiols (Chauhan and Boudjouk
2000). Polysiloxanes exhibiting fluorescent properties have also been obtained by
dehydrocondensation of fluorescent alcohols or phenols with PMHS, in the presence of different coupling catalysts (CPA, Et 3 N, K 2 CO 3 , Pt 2 [(ViSiMe 2 ) 2 O] 3 and
RhCl(PPh 3 ) 3 ) (Toulokhonova et al. 2003). Linear and cyclic polyamino-functional
polysiloxanes (useful as ingredients of coating compositions) have been prepared
by the dehydrocoupling of PMHS with alcohols or D
H 4 with aminoalcohols, catalyzed with (Ph 3 P) 3 RhCl (Ready et al. 2001; Boudjouk et al. 2002), thus showing
antineoplastic activity (Boudjouk et al. 2008).
Pd NPs formed from PMHS have also been stabilized using linear siloxane
oligomers containing cyanopropyl, hydrido and silanol groups. The presence of
Si-OH groups into the siloxane molecules also allows the polymer and the metal
particles to bind to a variety of oxide supports (Fu et al. 2010).
Hydrolysis of MD
H n M into silanol derivatives of PMHS has also been performed
using Pd(OAc) 2 and tris(dibenzylideneacetone)dipalladium(0) (Pd 2 (dba) 3 ) as catalysts. The modified polysiloxane is then functionalized through hydrosilylation with
3-cyanopropyl(chloro)dimethylsilane and crosslinked by condensation of Si-OH
groups with aluminum(III) s-buthoxide (Fu et al. 2010). Reduction of Pd(OAc) 2
with Si-H groups gives Pd NPs with a controlled size (Scheme 14.3) (Fu et al. 2010).
The dehydrocondensation reactions of PMHS with saturated primary n-alcohols
in the presence of anhydrous potassium hydroxide (KOH) or Pt/C at a temperature
about 40–60 °C gives n-alkyloxy-substituted methylsiloxane oligomers (Mukbaniani
et al. 2007a). The dehydrocondensation reaction between the Si-H and C-OH groups
of cellulose acetate (CA) has been carried out in acetone/N,N-dimethylformamide
(DMF) solution, and using Pt 2 [(ViSiMe 2 ) 2 O] 3 as a catalyst, resulting in the formation of Si-O-C bonds and crosslinking, followed by the manufacture of films thought
the casting methodology. Contact angle and thermal properties of modified CA have
been increased, while the dielectric constant values, T g , water vapor sorption and
surface roughness decreased (Stiubianu et al. 2010).
Scheme 14.2 Pd-catalyzed synthesis of silylesters. Adapted with permission from Chauhan
et al. (2003)
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications
(Scheme 14.2) (Chauhan et al. 2000). The active catalyst has been reused few times
(Chauhan et al. 2003).
By alcoholysis of PMHS with aliphatic alcohols (n-PrOH, i-PrOH, t-BuOH),
glycidol and aromatic and heteroaromatic substituted carbinols, in the presence of
RhCl(PPh 3 ) 3 (Wilkinson’s catalyst), new linear polysiloxanes with pendant grafts
have been prepared with high yields (Chauhan et al. 2001). The alcoholysis of
PMHS with hydroxyl derivatives of crown ethers gives poly(methylalkoxy-crown
ether)siloxanes, which could be used as new neutral carrier-type ion sensors
(Chauhan and Boudjouk 1999). Similarly, polythioethers have been prepared in
high yields, in reactions of PMHS and D
H 4 with thiols (Chauhan and Boudjouk
2000). Polysiloxanes exhibiting fluorescent properties have also been obtained by
dehydrocondensation of fluorescent alcohols or phenols with PMHS, in the presence of different coupling catalysts (CPA, Et 3 N, K 2 CO 3 , Pt 2 [(ViSiMe 2 ) 2 O] 3 and
RhCl(PPh 3 ) 3 ) (Toulokhonova et al. 2003). Linear and cyclic polyamino-functional
polysiloxanes (useful as ingredients of coating compositions) have been prepared
by the dehydrocoupling of PMHS with alcohols or D
H 4 with aminoalcohols, catalyzed with (Ph 3 P) 3 RhCl (Ready et al. 2001; Boudjouk et al. 2002), thus showing
antineoplastic activity (Boudjouk et al. 2008).
Pd NPs formed from PMHS have also been stabilized using linear siloxane
oligomers containing cyanopropyl, hydrido and silanol groups. The presence of
Si-OH groups into the siloxane molecules also allows the polymer and the metal
particles to bind to a variety of oxide supports (Fu et al. 2010).
Hydrolysis of MD
H n M into silanol derivatives of PMHS has also been performed
using Pd(OAc) 2 and tris(dibenzylideneacetone)dipalladium(0) (Pd 2 (dba) 3 ) as catalysts. The modified polysiloxane is then functionalized through hydrosilylation with
3-cyanopropyl(chloro)dimethylsilane and crosslinked by condensation of Si-OH
groups with aluminum(III) s-buthoxide (Fu et al. 2010). Reduction of Pd(OAc) 2
with Si-H groups gives Pd NPs with a controlled size (Scheme 14.3) (Fu et al. 2010).
The dehydrocondensation reactions of PMHS with saturated primary n-alcohols
in the presence of anhydrous potassium hydroxide (KOH) or Pt/C at a temperature
about 40–60 °C gives n-alkyloxy-substituted methylsiloxane oligomers (Mukbaniani
et al. 2007a). The dehydrocondensation reaction between the Si-H and C-OH groups
of cellulose acetate (CA) has been carried out in acetone/N,N-dimethylformamide
(DMF) solution, and using Pt 2 [(ViSiMe 2 ) 2 O] 3 as a catalyst, resulting in the formation of Si-O-C bonds and crosslinking, followed by the manufacture of films thought
the casting methodology. Contact angle and thermal properties of modified CA have
been increased, while the dielectric constant values, T g , water vapor sorption and
surface roughness decreased (Stiubianu et al. 2010).
Scheme 14.2 Pd-catalyzed synthesis of silylesters. Adapted with permission from Chauhan
et al. (2003)
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications