Modern Polymer Spect..

66
i v(CHZ)
fi
0)
m C
*
B
P
4
a
3000 2800 2600 2400 2200 2
Wavenumbers (cm-1)
' n
v(C=N)
I
2300 2250 2200 2150 2100 2050 2000
Wavenumbers (cm-q)
30
Figure 2-35. (a) FTIR polarization
spectra of'the v(CH?), \s(C-N) and
v(CD2) absorptions of a specifically
denterated P6a13 (see text) after laser
irradiation. (b) FTIR polarization spectra
of the v(CD7) atid i(C=N) absorptions
of a specifically deuterated
P6a12 (see text) after laser ii-radiation.
(IR radiation polarized parallel f. . .)
and perpendicular (-i to the laser
polarization).
Laser polarization
direction
CN
I
Figure 2-36. Schematic model of the irradiation-induced segmental
alignment in the polyesters relative to the polarization direction of the
argon-ion laser beam.
where the spacer merges into the main chain) and Figure 2-35b demonstrates the
almost negligible dichroism of the v(CD*)-region of a polyester which has been
deuterated in the alcoholic part of the main chain [loo]. On the basis of these
experimental results, the model shown in Figure 2-36 can be derived for the laser-