The influence of the degree of crystallinity and the syndiotacticity on the
1145, 1095, and 916 cm(-1) bands was studied. The intensity of the 1145 cm
(-1) band increased with increasing syndiotacticity at a low degree of crys
tallinity and with an increasing degree of crystallinity for a sample with
syndiotacticity. The intensity of 1095 cm(-1) band increased with increasin
g syndiotacticity at a fixed degree of crystallinity and was independent of
the degree of crystallinity for a sample. The intermolecular hydrogen bond
s were found to play an important role. The differences of the relations be
tween the absorbance ratio D-1145/D-1095 and the degree of crystallinity wi
th syndiotacticity were explained. The extent of the decrease of the intens
ity of 916 cm(-1) band with an increasing degree of crystallinity increased
with decreasing syndiotacticity. The predominant introduction of syndiotac
tic sequences in the crystals was assumed in the lower syndiotacticity. The
improved equation between the syndiotactic diad content in percent [s-(dia
d) %] and the absorbance ratio D-916/D-849 was established as s-(diad) % =
71.1 X (D-916/D-849)(0.327) for the films heated at 50 degreesC with use of
a syndiotactic. diad content obtained from NMR spectra. (C) 2001 John Wile
y & Sons, Inc.