363
(Me 2 PhSi) 2 O, which was obtained instead of the appropriate silanol (Schubert and
Lorenz 1997).
Dehydrocondensation of α,ω-dihydrooligodimethylsiloxanes with dimethylsiloxane-α,ω-diols carried out in dilute solution and catalyzed by CPA has led to the
production of macrocyclic and linear polysiloxanes. Yields of cyclics exceeded
70%. Contents of (Me 2 SiO) x (x > 6) were greater than in the case of ring-chain
equilibration process with D 4 and decamethylcyclopentasiloxane ((Me 2 SiO) 5 , D 5 )
(Foston and Beckham 2006).
In the presence of B(C 6 F 5 ) 3 , dehydrocondensation reactions of hydrosilanes with
alcohols and silanols (Deforth and Mignani 2001, 2003; Shinke et al. 2007) and
reduction of alcohols (Gevorgyan et al. 2000), ketones (Parks et al. 2000), aliphatic
aldehydes, aryl chlorides and carboxyl group have been easily occured (Gevorgyan
et al. 2001).
Hydrosilanes with functional groups: chloropropyl, carboxylic, hydroxyl, among
others, have been immobilized on silica surface via the dehydrocondensation reaction between silanol group of silica and Si-H group, which was catalyzed by
B(C 6 F 5 ) 3 at RT (Moitra et al. 2014). A catalytic dehydrogenative coupling of PMHS
with PDMS-α,ω-diols is one of the crosslinking methods of silicone elastomers
(Borisov et al. 1966; Lasocki et al. 1974; Chruściel and Lasocki 1983a) (see
Sect. 14.3).
14.6 Applications of PMHS
A number of practical applications of Si-H functional polysiloxanes (and also other
organosilicon polymers) is huge and is continuously growing.
14.6.1 General Applications of PMHS
The presence of the Si-H functional group into organosilicon polymers affects their
interesting chemical and physical properties and allows their numerous chemical
modifications. Thus, PMHS find many practical applications, such as:
1. In dehydrocondensation reactions with telechelic silanol (Si-OH) groups of
poly(dimethylsiloxanediol)s, as one of the crosslinking methods of RT vulcanized (RTV) silicone elastomers (Rościszewski 1964; Noll 1968; Hardman and
Torkelson 1989; White 1995; Kricheldorf 1996; Chruściel 1999c; Brook 2000;
Rościszewski and Zielecka 2002; Fejdyś-Kaczmarek et al. 2006);
and
2. In synthesis and modifications of properties of different types of polymers:
organosilicon, organic and inorganic, mainly in addition reactions to unsaturated
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications
(Me 2 PhSi) 2 O, which was obtained instead of the appropriate silanol (Schubert and
Lorenz 1997).
Dehydrocondensation of α,ω-dihydrooligodimethylsiloxanes with dimethylsiloxane-α,ω-diols carried out in dilute solution and catalyzed by CPA has led to the
production of macrocyclic and linear polysiloxanes. Yields of cyclics exceeded
70%. Contents of (Me 2 SiO) x (x > 6) were greater than in the case of ring-chain
equilibration process with D 4 and decamethylcyclopentasiloxane ((Me 2 SiO) 5 , D 5 )
(Foston and Beckham 2006).
In the presence of B(C 6 F 5 ) 3 , dehydrocondensation reactions of hydrosilanes with
alcohols and silanols (Deforth and Mignani 2001, 2003; Shinke et al. 2007) and
reduction of alcohols (Gevorgyan et al. 2000), ketones (Parks et al. 2000), aliphatic
aldehydes, aryl chlorides and carboxyl group have been easily occured (Gevorgyan
et al. 2001).
Hydrosilanes with functional groups: chloropropyl, carboxylic, hydroxyl, among
others, have been immobilized on silica surface via the dehydrocondensation reaction between silanol group of silica and Si-H group, which was catalyzed by
B(C 6 F 5 ) 3 at RT (Moitra et al. 2014). A catalytic dehydrogenative coupling of PMHS
with PDMS-α,ω-diols is one of the crosslinking methods of silicone elastomers
(Borisov et al. 1966; Lasocki et al. 1974; Chruściel and Lasocki 1983a) (see
Sect. 14.3).
14.6 Applications of PMHS
A number of practical applications of Si-H functional polysiloxanes (and also other
organosilicon polymers) is huge and is continuously growing.
14.6.1 General Applications of PMHS
The presence of the Si-H functional group into organosilicon polymers affects their
interesting chemical and physical properties and allows their numerous chemical
modifications. Thus, PMHS find many practical applications, such as:
1. In dehydrocondensation reactions with telechelic silanol (Si-OH) groups of
poly(dimethylsiloxanediol)s, as one of the crosslinking methods of RT vulcanized (RTV) silicone elastomers (Rościszewski 1964; Noll 1968; Hardman and
Torkelson 1989; White 1995; Kricheldorf 1996; Chruściel 1999c; Brook 2000;
Rościszewski and Zielecka 2002; Fejdyś-Kaczmarek et al. 2006);
and
2. In synthesis and modifications of properties of different types of polymers:
organosilicon, organic and inorganic, mainly in addition reactions to unsaturated
14 Hydrosilyl-Functional Polysiloxanes: Synthesis Reactions and Applications