Morphology and properties of urea-urethane nanocomposites obtained
from crystalline prepolymers with different chemical structure
Anna Boczkowska, Joanna Ryszkowska
Politechnika Warszawska, Wydzial/ Inzynierii Material/owej, Wol/oska
141, 02-507 Warszawa
It is well known that cast segmented urea-urethane polymers have their
macromolecules built from soft and hard segments. Hard segments
associate and form domains distributed in the soft-segment phase. Hard
segments create the reinforcing phase of urea-urethane composites.
Urea-urethane composites reinforced by the phase created from the hard
segments were obtained and studied. The polymer substrate - prepolymer
was formed in a reaction of oligodiols with diisocyanates. As a result
the prepolymer molecules were terminated with the reactive -NCO
groups. They formed the hard segments in a reaction with water. The
prepolymer was crystallized prior to the reaction of forming the hard
segments. Prepolymers with different chemical structure obtained from
tetramethylene-ether oligodiol (PTMEG) and ethylene oligoadipate (OAE)
were used for polymer preparation. The crystallization was carried out
at various temperatures. The differences in morphology and properties
of the composites obtained from prepolymers with different chemical
structure were found.
In the description of urea-urethane composites morphology various
techniques have been applied, including X-ray diffraction, optical and
scanning electron microscopy, atomic force microscopy, and thermal
analysis. Selected physical and mechanical properties were studied by
standard testing procedures developed for rubbers.
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