TY - JOUR
T1 - Phase morphology and molecular dynamics of a polyurethane ionomer reinforced with a liquid crystalline filler
AU - Charnetskaya, A. G.
AU - Polizos, G.
AU - Shtompel, V. I.
AU - Privalko, E. G.
AU - Kercha, Yu Yu
AU - Pissis, P.
PY - 2003/11
Y1 - 2003/11
N2 - Solution-blended binary composites of ionic segmented polyurethane (SPU-I) and liquid crystalline oligomer (LCO) were characterized by wide-angle (WAXS) and small-angle (SAXS) X-ray scattering, differential scanning calorimetry (DSC), thermally stimulated depolarization currents (TSDC) and dielectric relaxation spectroscopy (DRS). Both components mutually influenced their states of aggregation in blends (most significantly, promoting smearing-out of interfaces between stiff and soft chain fragments of SPU-I into broad interfacial regions of intermediate composition). Apparently, the blend with w=0.10 happened to be most favorable for crystallization of the LCO, while the degree of microphase separation for SPU-I became lower and the distribution of stiff domains by sizes became broader, the higher the LCO content. The overall molecular mobility of SPU-I in blends was significantly reduced. This reduction included the intensity of the secondary and the primary relaxations, and of the interfacial Maxwell-Wagner-Sillars (MWS) relaxation, whereas the transition temperatures remained essentially composition-invariant. The Arrhenius-like behavior for the dc conductivity concomitant to the non-Arrhenius (i.e., Vogel-Tammann-Fulcher) frequency dependence for the α relaxation in blends suggested a decoupling of conductivity from the motion of the SPU-I soft chain segments.
AB - Solution-blended binary composites of ionic segmented polyurethane (SPU-I) and liquid crystalline oligomer (LCO) were characterized by wide-angle (WAXS) and small-angle (SAXS) X-ray scattering, differential scanning calorimetry (DSC), thermally stimulated depolarization currents (TSDC) and dielectric relaxation spectroscopy (DRS). Both components mutually influenced their states of aggregation in blends (most significantly, promoting smearing-out of interfaces between stiff and soft chain fragments of SPU-I into broad interfacial regions of intermediate composition). Apparently, the blend with w=0.10 happened to be most favorable for crystallization of the LCO, while the degree of microphase separation for SPU-I became lower and the distribution of stiff domains by sizes became broader, the higher the LCO content. The overall molecular mobility of SPU-I in blends was significantly reduced. This reduction included the intensity of the secondary and the primary relaxations, and of the interfacial Maxwell-Wagner-Sillars (MWS) relaxation, whereas the transition temperatures remained essentially composition-invariant. The Arrhenius-like behavior for the dc conductivity concomitant to the non-Arrhenius (i.e., Vogel-Tammann-Fulcher) frequency dependence for the α relaxation in blends suggested a decoupling of conductivity from the motion of the SPU-I soft chain segments.
KW - Dielectric relaxation
KW - Liquid crystalline/polyurethane ionomer composties
KW - Microphase separation
KW - Molecular mobility
UR - http://www.scopus.com/inward/record.url?scp=0141509050&partnerID=8YFLogxK
U2 - 10.1016/S0014-3057(03)00136-8
DO - 10.1016/S0014-3057(03)00136-8
M3 - Article
AN - SCOPUS:0141509050
SN - 0014-3057
VL - 39
SP - 2167
EP - 2174
JO - European Polymer Journal
JF - European Polymer Journal
IS - 11
ER -