TY  - JOUR
AU  - Gambino, Thomas
AU  - Shafqat, Numera
AU  - Alegría, Angel
AU  - Malicki, Nicolas
AU  - Dronet, Séverin
AU  - Radulescu, Aurel
AU  - Nemkovskiy, Kirill
AU  - Arbe, Arantxa
AU  - Colmenero, Juan
TI  - Concentration Fluctuations and Nanosegregation in a Simplified Industrial Blend with Large Dynamic Asymmetry
JO  - Macromolecules
VL  - 53
IS  - 16
SN  - 1520-5835
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2020-03068
SP  - 7150 - 7160
PY  - 2020
AB  - Applying small-angle neutron scattering (SANS) on isotopically labeled samples, we have characterized the thermally driven concentration fluctuations (TCFs), one of the main factors in the phenomenology of blend dynamics, in mixtures of styrene–butadiene rubber (SBR) and oligomers of polystyrene (PS) with different compositions. This system displays a large dynamic asymmetry and is thus a good model to explore the tunability of properties of interest in the rubber industry. The SANS experiments, complemented with neutron diffraction with polarization analysis, have allowed one to determine the UCST behavior of the blend and establish its phase diagram. We find a close vicinity of the spinodal and vitrification lines for intermediate concentrations and samples rich in PS. This induces the freezing of the correlation length for TCF when decreasing the temperature and also has an impact on the reported dielectric response of these mixtures. Furthermore, we have deduced the relevant length scale for segmental relaxation from the comparison of SANS and dielectric results. The values found (≈1.5–2 nm) are close to the Kuhn lengths of the components. The relevance of nanometric length scales in this system could also be tentatively attributed to an underlying nanodomain structure associated with the segregation of phenyl rings and main chains, supported by complementary X-ray diffraction experiments.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000566339100036
DO  - DOI:10.1021/acs.macromol.0c01376
UR  - https://juser.fz-juelich.de/record/884057
ER  -