486
L. V. Karabanova et al.
amine groups, carboxylic acid groups, acrylic groups, epoxy groups [22–24]. Due to
variety in reactive groups in the outer layer of POSS, it becomes possible to create
the nanocomposites and hybrids using such POSS for different applications. These
could be the multifunction materials from polymer systems to ceramics.
Depending on how much reactive functional groups are there in the POSS, the
POSS particle could be included as part of main polymer chain [25], could create
cross-linked system [26], or could be a cage in backbone [25, 27]. Compared with
traditional polymers, materials contained POSS have significant advantages: thermal
conductivity, increased hydrophobicity, chemical resistance, mechanical strength,
hardness, increased temperature of thermal decomposition. The incorporation of
polyhedral oligomeric silsesquioxane (POSS) macromer into the polyurethane matrix
results in the permeability of gas transport [10], increasing of the conduction and the
permittivity [11]. The addition of POSS into the PU’s polymers leads to enhancement
of their thermal stability [12, 13], also to improving the mechanical properties [14,
15] due to the reinforcement effect of the nanoparticles. The increasing of resistance
of the nanocomposites against oxidation was also detected by authors [14, 16] due
to incorporation of POSS to the systems. These favorable effects are evident mainly
when the functionalized POSS particles are integrated into polymer chains via a
chemical reaction.
In our study, 1, 2-propanediolisobutyl-POSS (POSS) was used as a functionalized
nanofiller for PU matrix. The presence of two reactive hydroxyl groups in peripheral substituent of POSS allowed it to react with diisocyanates, so resulting in the
embedding of the POSS particles into the main polymer chain of the nanocomposites
[20–22, 25].
The objective of the present study was the creation of the nanocomposites
based on polyurethane matrix and 1,2-propanediolisobutyl polyhedral oligomeric
silsesquioxane (POSS), and investigation of the effects induced by the POSS content
on the structure, morphology, thermal, and dynamic mechanical properties of the
nanocomposites.
2 Materials and Testing Methods
2.1 Materials
1,2-propanediolisobutyl polyhedral oligomeric silsesquioxane (POSS) was
purchased from Sigma-Aldrich Inc. Trimethylolpropane (TMP) and toluene 2,4diisocyanate (TDI) were obtained from Merck. The reagents were of high purity and
used as received. The oligoetherglycol with Mw = 5.000 g/mol
−1 (Laprol 5003) was
obtained from commercial sources and dried with liquid nitrogen under vacuum at
75–80 °C for 5 h before use. Ethyl acetate was used as a solvent and its purification
was done by distillation in vacuum.
L. V. Karabanova et al.
amine groups, carboxylic acid groups, acrylic groups, epoxy groups [22–24]. Due to
variety in reactive groups in the outer layer of POSS, it becomes possible to create
the nanocomposites and hybrids using such POSS for different applications. These
could be the multifunction materials from polymer systems to ceramics.
Depending on how much reactive functional groups are there in the POSS, the
POSS particle could be included as part of main polymer chain [25], could create
cross-linked system [26], or could be a cage in backbone [25, 27]. Compared with
traditional polymers, materials contained POSS have significant advantages: thermal
conductivity, increased hydrophobicity, chemical resistance, mechanical strength,
hardness, increased temperature of thermal decomposition. The incorporation of
polyhedral oligomeric silsesquioxane (POSS) macromer into the polyurethane matrix
results in the permeability of gas transport [10], increasing of the conduction and the
permittivity [11]. The addition of POSS into the PU’s polymers leads to enhancement
of their thermal stability [12, 13], also to improving the mechanical properties [14,
15] due to the reinforcement effect of the nanoparticles. The increasing of resistance
of the nanocomposites against oxidation was also detected by authors [14, 16] due
to incorporation of POSS to the systems. These favorable effects are evident mainly
when the functionalized POSS particles are integrated into polymer chains via a
chemical reaction.
In our study, 1, 2-propanediolisobutyl-POSS (POSS) was used as a functionalized
nanofiller for PU matrix. The presence of two reactive hydroxyl groups in peripheral substituent of POSS allowed it to react with diisocyanates, so resulting in the
embedding of the POSS particles into the main polymer chain of the nanocomposites
[20–22, 25].
The objective of the present study was the creation of the nanocomposites
based on polyurethane matrix and 1,2-propanediolisobutyl polyhedral oligomeric
silsesquioxane (POSS), and investigation of the effects induced by the POSS content
on the structure, morphology, thermal, and dynamic mechanical properties of the
nanocomposites.
2 Materials and Testing Methods
2.1 Materials
1,2-propanediolisobutyl polyhedral oligomeric silsesquioxane (POSS) was
purchased from Sigma-Aldrich Inc. Trimethylolpropane (TMP) and toluene 2,4diisocyanate (TDI) were obtained from Merck. The reagents were of high purity and
used as received. The oligoetherglycol with Mw = 5.000 g/mol
−1 (Laprol 5003) was
obtained from commercial sources and dried with liquid nitrogen under vacuum at
75–80 °C for 5 h before use. Ethyl acetate was used as a solvent and its purification
was done by distillation in vacuum.