488
L. V. Karabanova et al.
under nitrogen. The glass transition temperature (T g ) was taken as the midpoint of
the curve at the change in heat capacity.
2.2.3 Thermogravimetric Analysis (TGA)
TGA was undertaken using a TA Instruments Q500 in hermetically sealed aluminum
pans. In a dry nitrogen atmosphere, the samples (about 5–6 mg) were heated from
ambient temperature to 700 °C at the heating rate of 20 °C min
−1 . The initial thermal
degradation temperature was taken as the onset temperature at which a mass loss of
5 wt% occurs.
2.2.4 Dynamic Mechanical Analyses (DMA)
Dynamic mechanical measurements were carried out using a Dynamic Mechanical
Thermal Analyzer Type DMA Q800 from TA Instruments over the temperature
range from −100 to +220 °C and at fixed frequency 10 Hz with a heating rate
of 3 °C/min. The experiments were performed under tension mode on rectangular
specimens (35 mm × 5 mm × 1 mm). The samples were subsequently subjected to
the following thermal cycle during DMA measurements: a first run from 20 °C up
to 100 °C and then second run from –100 °C up to +220 °C. The second run was
used for analysis of the results.
2.2.5 Wide-Angle X-Ray Scattering (WAXS)
The peculiarities of the amorphous structure of the polyurethane (PU) and the layered
structure of 2-propanediolisobutyl polyhedral oligomeric silsesquioxane (POSS)
were investigated by the wide-angle X-ray scattering (WAXS) method using an
X-ray diffractometer DRON-4-07, whose optical scheme was performed using the
Debye–Scherrer method (the “passing through” the sample of the primary X-ray
beam).
2.2.6 Small-Angle X-Ray Scattering (SAXS)
The microphase structure of the native PU and the nanocomposites contained from 1
to 10 wt% of POSS was investigated by the method of small-angle X-ray scattering
(SAXS) using a small-angle X-ray camera KRM-1, the slit collimation (primary
beam) of which was performed by the Kratky method [29]. The geometrical parameters of the camera’s collimation system satisfied the conditions of the infinite height
of the collimation slit. The experimental values of the scattering intensity were
normalized using the size of the sample’s volume and the factor of weakening of
L. V. Karabanova et al.
under nitrogen. The glass transition temperature (T g ) was taken as the midpoint of
the curve at the change in heat capacity.
2.2.3 Thermogravimetric Analysis (TGA)
TGA was undertaken using a TA Instruments Q500 in hermetically sealed aluminum
pans. In a dry nitrogen atmosphere, the samples (about 5–6 mg) were heated from
ambient temperature to 700 °C at the heating rate of 20 °C min
−1 . The initial thermal
degradation temperature was taken as the onset temperature at which a mass loss of
5 wt% occurs.
2.2.4 Dynamic Mechanical Analyses (DMA)
Dynamic mechanical measurements were carried out using a Dynamic Mechanical
Thermal Analyzer Type DMA Q800 from TA Instruments over the temperature
range from −100 to +220 °C and at fixed frequency 10 Hz with a heating rate
of 3 °C/min. The experiments were performed under tension mode on rectangular
specimens (35 mm × 5 mm × 1 mm). The samples were subsequently subjected to
the following thermal cycle during DMA measurements: a first run from 20 °C up
to 100 °C and then second run from –100 °C up to +220 °C. The second run was
used for analysis of the results.
2.2.5 Wide-Angle X-Ray Scattering (WAXS)
The peculiarities of the amorphous structure of the polyurethane (PU) and the layered
structure of 2-propanediolisobutyl polyhedral oligomeric silsesquioxane (POSS)
were investigated by the wide-angle X-ray scattering (WAXS) method using an
X-ray diffractometer DRON-4-07, whose optical scheme was performed using the
Debye–Scherrer method (the “passing through” the sample of the primary X-ray
beam).
2.2.6 Small-Angle X-Ray Scattering (SAXS)
The microphase structure of the native PU and the nanocomposites contained from 1
to 10 wt% of POSS was investigated by the method of small-angle X-ray scattering
(SAXS) using a small-angle X-ray camera KRM-1, the slit collimation (primary
beam) of which was performed by the Kratky method [29]. The geometrical parameters of the camera’s collimation system satisfied the conditions of the infinite height
of the collimation slit. The experimental values of the scattering intensity were
normalized using the size of the sample’s volume and the factor of weakening of