Pr. Nair et al., IMIDE-MODIFIED POLYURETHANES, SYNTHESES, THERMAL, IMIDE-MODIFIED POLYURETHANES, AND MECHANICAL CHARACTERISTICS, Journal of applied polymer science, 70(8), 1998, pp. 1483-1491
Polyurethanes based on polyethylene glycol and hydroxy-terminated poly
butadiene, bearing pyromellitimide groups in the backbone, were synthe
sised via a sequential method. The diisocyanate and diamine telechelic
precursor polymers, the polyamic acid intermediate and the polyimides
were characterized by physicochemical and thermoanalytical techniques
. The imide content could be varied in the chain through selection of
the polyol of desired molecular weight or by a chain extension process
of the diisocyanate precursor. The thermal and mechanical properties
of the imide-modified polyurethane increased proportionate to the hard
segment content, constituted by the imide and the urea groups. The pr
esence of the imide group resulted in better thermomechanical profile
and caused enhancement in glass transition temperature of the modified
polyurethane vis-a-vis the unmodified resin. (C) 1998 John Wiley & So
ns, Inc.