trimethoxysilyl moieties in the hydrosilylation products was confirmed by their
1
H
and
13 C NMR spectra (
1 H NMR: signals in the range of d = 5.9–6.2 ppm—
CF 2 H terminal group, d = 2.50–2.80, *3.00 ppm—protons of epoxy groups,
d = 3.47–3.50 ppm—protons of OCH 3 group;
13 C NMR: d = 105–118 ppm—
carbon atoms adjacent to fluorine atoms, d = 44, 51 ppm—carbon atoms in epoxy
groups, d = 50 ppm OCH 3 groups). Formation of the CH 2 CH 2 linkages upon
hydrosilylation was manifested by the appearance of the IR bands in the range of
2800–3000 cm
−1 and the
29 Si NMR signal at −22 ppm. Coatings fabricated using
copolymers containing mixed groups exhibited good adherence to the glass substrate provided by glycidoxypropyl or trimethoxysilyl moieties and hydrophobic or
superhydrophobic surface properties ensured by fluoroalkylether ones [24].
Consecutive hydrosilylation of the appropriate allyl alkene derivatives
(fluorine-containing compound first) by PHMS (Karstedt’s catalyst, toluene, 80 °C)
made it possible to prepare siloxane polyelectrolytes with other mixed, i.e., tetraglyme and lithiumsulfonate-terminated perfluoroether side chains (Table 12.1, S10
—x = 4, R = CH 3 and S15) [59]. Significant reduction in the FTIR Si–H band at
2161 cm
−1 after the processes indicated high degree of PHMS functionalization;
based on
1 H NMR spectra, it was established that about 3% unreacted Si–H groups
were preserved in the materials.
1 H NMR spectra were also applied to determine the
ratios of tetraglyme and perfluoroether side chains in the samples. Additionally,
polyelectrolytes prepared in the work were characterized by
13 C and
19
F NMR
spectroscopies. In their FTIR spectra, characteristic bands in the range of 1200–
1350 and 1080–1200 cm
−1 corresponding to CF 2 group asymmetric and symmetric
stretching vibrations, respectively, appeared [59].
Fluoroester group-functionalized polysiloxanes (Table 12.1, S16) were prepared
by the reaction between 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA) and PHMS
(Karstedt’s catalyst, p-xylene, 100–130 °C) [60]. In another work, polysiloxanes
with different grafting densities of fluoroester groups were synthesized by hydrosilylation of tridecafluorooctyl methacrylate (H 2 C=C(CH 3 )COCH 2 CH 2
(CF 2 ) 5 CF 3 ) with PHMS-DMS copolymer; they were subsequently reacted with
vinyltriethoxysilane (H 2 C=CHSi(OCH 2 CH 3 ) 3 ) to form bifunctional polysiloxanes
(Table 12.1, polymer B-S17 and B-S18) (Speier’s catalyst, trifluorotoluene as
solvent, 80 °C) [52]. FTIR spectra of all fluoroester-modified polymers contained a
characteristic, strong band at 1756 cm
−1 [60] or 1730 cm
−1 [52] assigned to carbonyl (C=O) group stretching vibrations. In the spectrum of the monofunctional
polymer, there was also a maximum at 1180 cm
−1 due to the vibrations of the C–F
bond [60]. The Si–H band at *2160 cm
−1 either was absent [52] or showed very
low intensity [60] which proved complete or high degree of polymer functionalization. These results were in concert with the
1 H NMR spectra: No [52] or weak
[60] signal corresponding to the proton of the Si–H group (d = 4.7 ppm) was
observed. Comparison of its integral intensities in the spectra of the initial and
functionalized PHMS allowed finding out that in the monofunctional polymer
grafting ratio of 92.1% was reached [60]. Moreover,
1 H NMR spectra confirmed the
presence of both organic groups in the bifunctional polymer—their signals were
seen at d = 4.4 ppm (OCH 2 CH 2 CF 2 ), 2.5 ppm (OCH 2 CH 2 CF 2 ), d = 0.6 ppm (Si
12 Application of Spectroscopic Methods in the Studies …
377
1
H
and
13 C NMR spectra (
1 H NMR: signals in the range of d = 5.9–6.2 ppm—
CF 2 H terminal group, d = 2.50–2.80, *3.00 ppm—protons of epoxy groups,
d = 3.47–3.50 ppm—protons of OCH 3 group;
13 C NMR: d = 105–118 ppm—
carbon atoms adjacent to fluorine atoms, d = 44, 51 ppm—carbon atoms in epoxy
groups, d = 50 ppm OCH 3 groups). Formation of the CH 2 CH 2 linkages upon
hydrosilylation was manifested by the appearance of the IR bands in the range of
2800–3000 cm
−1 and the
29 Si NMR signal at −22 ppm. Coatings fabricated using
copolymers containing mixed groups exhibited good adherence to the glass substrate provided by glycidoxypropyl or trimethoxysilyl moieties and hydrophobic or
superhydrophobic surface properties ensured by fluoroalkylether ones [24].
Consecutive hydrosilylation of the appropriate allyl alkene derivatives
(fluorine-containing compound first) by PHMS (Karstedt’s catalyst, toluene, 80 °C)
made it possible to prepare siloxane polyelectrolytes with other mixed, i.e., tetraglyme and lithiumsulfonate-terminated perfluoroether side chains (Table 12.1, S10
—x = 4, R = CH 3 and S15) [59]. Significant reduction in the FTIR Si–H band at
2161 cm
−1 after the processes indicated high degree of PHMS functionalization;
based on
1 H NMR spectra, it was established that about 3% unreacted Si–H groups
were preserved in the materials.
1 H NMR spectra were also applied to determine the
ratios of tetraglyme and perfluoroether side chains in the samples. Additionally,
polyelectrolytes prepared in the work were characterized by
13 C and
19
F NMR
spectroscopies. In their FTIR spectra, characteristic bands in the range of 1200–
1350 and 1080–1200 cm
−1 corresponding to CF 2 group asymmetric and symmetric
stretching vibrations, respectively, appeared [59].
Fluoroester group-functionalized polysiloxanes (Table 12.1, S16) were prepared
by the reaction between 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA) and PHMS
(Karstedt’s catalyst, p-xylene, 100–130 °C) [60]. In another work, polysiloxanes
with different grafting densities of fluoroester groups were synthesized by hydrosilylation of tridecafluorooctyl methacrylate (H 2 C=C(CH 3 )COCH 2 CH 2
(CF 2 ) 5 CF 3 ) with PHMS-DMS copolymer; they were subsequently reacted with
vinyltriethoxysilane (H 2 C=CHSi(OCH 2 CH 3 ) 3 ) to form bifunctional polysiloxanes
(Table 12.1, polymer B-S17 and B-S18) (Speier’s catalyst, trifluorotoluene as
solvent, 80 °C) [52]. FTIR spectra of all fluoroester-modified polymers contained a
characteristic, strong band at 1756 cm
−1 [60] or 1730 cm
−1 [52] assigned to carbonyl (C=O) group stretching vibrations. In the spectrum of the monofunctional
polymer, there was also a maximum at 1180 cm
−1 due to the vibrations of the C–F
bond [60]. The Si–H band at *2160 cm
−1 either was absent [52] or showed very
low intensity [60] which proved complete or high degree of polymer functionalization. These results were in concert with the
1 H NMR spectra: No [52] or weak
[60] signal corresponding to the proton of the Si–H group (d = 4.7 ppm) was
observed. Comparison of its integral intensities in the spectra of the initial and
functionalized PHMS allowed finding out that in the monofunctional polymer
grafting ratio of 92.1% was reached [60]. Moreover,
1 H NMR spectra confirmed the
presence of both organic groups in the bifunctional polymer—their signals were
seen at d = 4.4 ppm (OCH 2 CH 2 CF 2 ), 2.5 ppm (OCH 2 CH 2 CF 2 ), d = 0.6 ppm (Si
12 Application of Spectroscopic Methods in the Studies …
377