A series of poly(benzophenoneimide)s(C-m-BP-PIs) having n-alkyloxymeth
yl side chains(-CH2O-n-CmH2m+1, m=4, 6, 8) have been examined by X-ray
diffraction, differential scanning calorimetry(DSC) and polarizing op
tical microscopy. The samples showed basically two phase transitions a
nd both transtion temperatures decreased with increasing side chain le
ngth. The first transitions were ascribed to glass transitions and the
second ones were assigned to liquid crystal-to-isotropic transitions.
Eicosane(n-C20H42) which is chemically very similar to the side chain
was miscible with the side chains of C-8-BP-PI, which induced depress
ion of the glass transition temperature.