tris(trimethylsilyl)hexyl side chains contained the line at d = 2.1 ppm corresponding to [CSi(CH 3 ) 3 ] units [34].
1 H NMR revealed that some amounts (ca. 2%
in [34] and 10–15% in [35]) of Markovnikov products were formed in the reactions.
Kowalewska and Stańczyk [34] attributed generation of this adduct to hydrosilylation of AGE, whereas Rutnakornpituk [35]—to hydrosilylation of allyl cyanide.
The functionalized polymers prepared by Kowalewska and Stańczyk [34] were
subjected to photocrosslinking in order to obtain solid membranes.
13 C NMR
spectra of the cross-linked materials contained no signals assigned to epoxy groups
which meant that they participated in the cross-linking process. Rutnakornpituk
[35] applied polysiloxanes modified by cyanopropyl and glycidoxypropyl pendant
groups as reactive additives in the fabrication of epoxy-novolac resin networks.
Min et al. [36] reacted epoxy groups in their modified polysiloxanes with Naminoethylpiperazine which resulted in the polymers functionalized by dodecyl and
piperazine groups (Table 12.1, S4 and S5). They were characterized by FTIR (the
bands at 1260 and 3430 cm
−1 due to C–N and N–H vibrations, respectively) and
1 H
NMR (signals in the d range of 2.1–3.8 ppm assigned to protons in piperazine
moieties) spectroscopies and used to prepare emulsions from which coatings on
cotton fabrics were fabricated [36].
The already described investigations on epoxy-substituted polysiloxanes were
application-oriented. Spectroscopic methods were employed in these studies to
characterize the synthesized materials. Work by Cancouët et al. [25] demonstrates
that spectroscopy can be a valuable tool to characterize the course of the process of
incorporation of epoxy groups into polysiloxanes as well. These researchers conducted hydrosilylation of AGE by PHMS and PHMS-DMS copolymers of various
compositions at 70 °C, in toluene, with Speier’s catalyst. Kinetic studies were based
on determination of changes in concentrations of Si–H groups using FTIR spectra of
the samples withdrawn from the reaction mixtures after certain time periods (calibration of the Si–H band at 2160 cm
−1 with the solutions of 1,1,3,
3-tetramethyldisiloxane in toluene of known concentrations was made first). Results
obtained led to the conclusion that a given [SiO 2 (CH 3 )H] unit in a polymer chain is
significantly more reactive when it is a part of larger similar units than when it is
isolated between adjacent dimethyl-substituted units. This finding was corroborated
by the
29 Si NMR spectra of the initial PHMS-DMS copolymer and the same
copolymer after incomplete reaction with AGE. They clearly showed that the units
of the [SiO 2 (CH 3 )H] 3 triad (signal at d = *−35 ppm) were consumed first [25].
12.4.2.2 Polymers with Ester, Polyether, and Other
Oxygen-Containing Side Groups
Oxygen-containing substituents, being polar, can turn hydrophobic polysiloxanes
into more hydrophilic materials or change their other physical properties by
inducing strong intermolecular interactions, absent in non-functionalized polymers.
They can also provide reactivity that allows for, e.g., polymer cross-linking or (in
the case of coatings) ensures its good adhesion to the substrate material. Among
12 Application of Spectroscopic Methods in the Studies …
371
1 H NMR revealed that some amounts (ca. 2%
in [34] and 10–15% in [35]) of Markovnikov products were formed in the reactions.
Kowalewska and Stańczyk [34] attributed generation of this adduct to hydrosilylation of AGE, whereas Rutnakornpituk [35]—to hydrosilylation of allyl cyanide.
The functionalized polymers prepared by Kowalewska and Stańczyk [34] were
subjected to photocrosslinking in order to obtain solid membranes.
13 C NMR
spectra of the cross-linked materials contained no signals assigned to epoxy groups
which meant that they participated in the cross-linking process. Rutnakornpituk
[35] applied polysiloxanes modified by cyanopropyl and glycidoxypropyl pendant
groups as reactive additives in the fabrication of epoxy-novolac resin networks.
Min et al. [36] reacted epoxy groups in their modified polysiloxanes with Naminoethylpiperazine which resulted in the polymers functionalized by dodecyl and
piperazine groups (Table 12.1, S4 and S5). They were characterized by FTIR (the
bands at 1260 and 3430 cm
−1 due to C–N and N–H vibrations, respectively) and
1 H
NMR (signals in the d range of 2.1–3.8 ppm assigned to protons in piperazine
moieties) spectroscopies and used to prepare emulsions from which coatings on
cotton fabrics were fabricated [36].
The already described investigations on epoxy-substituted polysiloxanes were
application-oriented. Spectroscopic methods were employed in these studies to
characterize the synthesized materials. Work by Cancouët et al. [25] demonstrates
that spectroscopy can be a valuable tool to characterize the course of the process of
incorporation of epoxy groups into polysiloxanes as well. These researchers conducted hydrosilylation of AGE by PHMS and PHMS-DMS copolymers of various
compositions at 70 °C, in toluene, with Speier’s catalyst. Kinetic studies were based
on determination of changes in concentrations of Si–H groups using FTIR spectra of
the samples withdrawn from the reaction mixtures after certain time periods (calibration of the Si–H band at 2160 cm
−1 with the solutions of 1,1,3,
3-tetramethyldisiloxane in toluene of known concentrations was made first). Results
obtained led to the conclusion that a given [SiO 2 (CH 3 )H] unit in a polymer chain is
significantly more reactive when it is a part of larger similar units than when it is
isolated between adjacent dimethyl-substituted units. This finding was corroborated
by the
29 Si NMR spectra of the initial PHMS-DMS copolymer and the same
copolymer after incomplete reaction with AGE. They clearly showed that the units
of the [SiO 2 (CH 3 )H] 3 triad (signal at d = *−35 ppm) were consumed first [25].
12.4.2.2 Polymers with Ester, Polyether, and Other
Oxygen-Containing Side Groups
Oxygen-containing substituents, being polar, can turn hydrophobic polysiloxanes
into more hydrophilic materials or change their other physical properties by
inducing strong intermolecular interactions, absent in non-functionalized polymers.
They can also provide reactivity that allows for, e.g., polymer cross-linking or (in
the case of coatings) ensures its good adhesion to the substrate material. Among
12 Application of Spectroscopic Methods in the Studies …
371