Neutron Reflectivity Study of Diblock Formation During Reactive Blending Processes.
Neutron Reflectivity Study of Diblock Formation During
Reactive Blending Processes.
(399 K)
Hayashi, M.; Grull, H.; Esker, A. R.; Sung, L. P.;
Satija, S.; Han, C. C.; Weber, M.; Hashimoto, T.
Macromolecules, Vol. 33, No. 17, 6485-6494, 2001.
Keywords:
polymer thin films; polymer blend films; diblock
copolymer formation; neutron reflectivity
Abstract:
In a series of neutron reflectivity experiments, we
studied the fundamental process of diblock formation
during reactive blending processes of an immiscible
blend comprised of normal polysulfone (hPSU) containing
30% reactive end group-modified deuterated polysulfone
(dPSU-R) and polyamide (PA). Diblock formation
(dPSU-b-PA) and dPSU-R enrichment at the interface
between the incompatible polymers were monitored in thin
bilayer films using neutron reflectivity. These results
are compared to experimental results obtained with
bilayer films of pure non-reactive deuterated PSU (dPSU)
and PA and pure reactive dPSU-R and PA, respectively.
The interfacial width in the pure reactive system is
slightly larger than that in the pure non-reactive
system, indicating the formation of a diblock copolymer
at the interface of the reactive system. This study
concludes that it is possible to diminish but not
eliminate the interfacial tenxion ({gamma} > O) between
the PSU and PA, as it is not possible to build up a
large enough normalized surface excesses, z*/Rg < 1, of
dPSU-b-PA.
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National Institute of Standards and Technology
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