containing 1 mol% of Si–H moieties was complete after 80 min independently of
the catalyst applied; however, only with Karstedt’s catalyst their 100% conversion
was attained (Fig. 12.4b). This conclusion was confirmed by
1 H NMR spectra
(Fig. 12.4c) which contained no signal corresponding to protons of Si-H groups
(d = 4.7 ppm) when Karstedt’s catalyst was used. Moreover, the spectra proved
incorporation of methacrylic moieties into the macromonomers: They showed the
signals at d = 6.1 and 5.5 ppm (C=CH 2 ), d = 4.1 ppm (OCH 2 ), and d = 1.9 ppm
(CH 3 ). The gels exhibited high optical transparency. According to UV-Vis spectra,
their transmittance in the visible range exceeded 95%. They absorbed UV light
below 310 nm which was advantageous since ensured their built-in UV protection.
Wang et al. [37] subjected PHMS-DMS copolymers (containing 0.18 wt% or
0.50 wt% of Si–H groups) to the reactions with methyl methacrylate (MMA) using
dichloro(dicyclopentadienyl)platinum(II) complex as catalyst and tetrahydrofuran
(THF) as solvent. Polysiloxanes with incorporated side groups originating from
MMA (Table 12.1, polymer B-S7) were obtained in this way. Then, oxidative
polymerization of aniline was performed in their presence to yield electroconductive, pseudo-graft copolymers in which polyaniline (PANI) and functionalized
polysiloxane were linked by hydrogen bonds between amine/imine groups of PANI
and carbonyl groups of the modified polysiloxane. Chemical structures of the
prepared materials were investigated by FTIR,
1 H, and
29 Si NMR spectroscopies.
FTIR spectra of the functionalized copolymers contained no band at 2156 cm
−1 ,
whereas a strong band at 1737 cm
−1 was visible evidencing complete consumption
of copolymer’s Si–H groups and incorporation of carbonyl moieties, respectively,
upon hydrosilylation.
1 H NMR spectra proved formation of b product in the process
(signal at d = 1.2 ppm, SiCH 2 CH(CH 3 )COOCH 3 ) and confirmed modification of
the polymers by the units derived from MMA (signals at: d = 2.6 ppm, SiCH 2 CH
(CH 3 )COOCH 3 and d = 3.7 ppm, COOCH 3 ).
29 Si NMR spectra, similarly to
FTIR, contained no signal corresponding to the units with Si–H bond but showed,
like
1 H NMR, formation of the expected [OSi(CH 3 )(CH 2 )] units (signal at
d = −24 ppm). Additionally, using
1 H NMR spectra fractions of MMA units in the
modified siloxane copolymers were calculated.
It should be noted that hydrosilylation of alkyl acrylates and methacrylates, due
to the conjugated nature of their molecules (p–p conjugation), can lead to the
products of 1,2- and 1,4-addition. The first case involves the reaction of Si–H
groups and C=C bonds generating anti-Markovnikov (b) and Markovnikov (a)
products (Fig. 12.1). In the second one ,both C=C and C=O bonds participate in the
process and the unsaturated compound with an internal C=C bond is formed.
Lin et al. [38] found that hydrosilylation of MMA and octadecyl acrylate
(OA) with PHMS-DMS copolymers (H 2 PtCl 6 catalyst, toluene, 100–130 °C) was a
b 1,2-addition. This was manifested by a strong IR band at *1740 cm
−1 due to
C=O group in saturated esters and the
1 H NMR signals at d = 1.2, 2.6, 3.7 ppm
(assignments as in the work [37]) in the spectra of the obtained compounds. No
1
H
NMR lines at d = 1.1 ppm or 1.6 ppm attributed to protons of methyl groups
bonded to CHCOOR in the a 1,2-addition or linked to C=C in the 1,4-addition,
respectively, were observed. Hydrolysis of incorporated MMA moieties
12 Application of Spectroscopic Methods in the Studies …
373
the catalyst applied; however, only with Karstedt’s catalyst their 100% conversion
was attained (Fig. 12.4b). This conclusion was confirmed by
1 H NMR spectra
(Fig. 12.4c) which contained no signal corresponding to protons of Si-H groups
(d = 4.7 ppm) when Karstedt’s catalyst was used. Moreover, the spectra proved
incorporation of methacrylic moieties into the macromonomers: They showed the
signals at d = 6.1 and 5.5 ppm (C=CH 2 ), d = 4.1 ppm (OCH 2 ), and d = 1.9 ppm
(CH 3 ). The gels exhibited high optical transparency. According to UV-Vis spectra,
their transmittance in the visible range exceeded 95%. They absorbed UV light
below 310 nm which was advantageous since ensured their built-in UV protection.
Wang et al. [37] subjected PHMS-DMS copolymers (containing 0.18 wt% or
0.50 wt% of Si–H groups) to the reactions with methyl methacrylate (MMA) using
dichloro(dicyclopentadienyl)platinum(II) complex as catalyst and tetrahydrofuran
(THF) as solvent. Polysiloxanes with incorporated side groups originating from
MMA (Table 12.1, polymer B-S7) were obtained in this way. Then, oxidative
polymerization of aniline was performed in their presence to yield electroconductive, pseudo-graft copolymers in which polyaniline (PANI) and functionalized
polysiloxane were linked by hydrogen bonds between amine/imine groups of PANI
and carbonyl groups of the modified polysiloxane. Chemical structures of the
prepared materials were investigated by FTIR,
1 H, and
29 Si NMR spectroscopies.
FTIR spectra of the functionalized copolymers contained no band at 2156 cm
−1 ,
whereas a strong band at 1737 cm
−1 was visible evidencing complete consumption
of copolymer’s Si–H groups and incorporation of carbonyl moieties, respectively,
upon hydrosilylation.
1 H NMR spectra proved formation of b product in the process
(signal at d = 1.2 ppm, SiCH 2 CH(CH 3 )COOCH 3 ) and confirmed modification of
the polymers by the units derived from MMA (signals at: d = 2.6 ppm, SiCH 2 CH
(CH 3 )COOCH 3 and d = 3.7 ppm, COOCH 3 ).
29 Si NMR spectra, similarly to
FTIR, contained no signal corresponding to the units with Si–H bond but showed,
like
1 H NMR, formation of the expected [OSi(CH 3 )(CH 2 )] units (signal at
d = −24 ppm). Additionally, using
1 H NMR spectra fractions of MMA units in the
modified siloxane copolymers were calculated.
It should be noted that hydrosilylation of alkyl acrylates and methacrylates, due
to the conjugated nature of their molecules (p–p conjugation), can lead to the
products of 1,2- and 1,4-addition. The first case involves the reaction of Si–H
groups and C=C bonds generating anti-Markovnikov (b) and Markovnikov (a)
products (Fig. 12.1). In the second one ,both C=C and C=O bonds participate in the
process and the unsaturated compound with an internal C=C bond is formed.
Lin et al. [38] found that hydrosilylation of MMA and octadecyl acrylate
(OA) with PHMS-DMS copolymers (H 2 PtCl 6 catalyst, toluene, 100–130 °C) was a
b 1,2-addition. This was manifested by a strong IR band at *1740 cm
−1 due to
C=O group in saturated esters and the
1 H NMR signals at d = 1.2, 2.6, 3.7 ppm
(assignments as in the work [37]) in the spectra of the obtained compounds. No
1
H
NMR lines at d = 1.1 ppm or 1.6 ppm attributed to protons of methyl groups
bonded to CHCOOR in the a 1,2-addition or linked to C=C in the 1,4-addition,
respectively, were observed. Hydrolysis of incorporated MMA moieties
12 Application of Spectroscopic Methods in the Studies …
373