Biology Reference
In-Depth Information
The XRD pattern of the product obtained from PLLA showed
two diffraction peaks at 2
(Fig. 8.6d),
which was completely different from that of amylose (Fig. 8.6a) and
PLLA (Fig. 8.6b), indicating that the crystalline structure of PLLA
was disappeared and the diameter of amylose helix was changed
owing to the inclusion of PLLA. Interestingly, the diffraction peaks
of the product appeared at lower angles compared with those of the
inclusion complexes composed of amylose and the slender guest
polymers such as PTHF (2
q
equal to 11-12
°
and 18-19
°
) (Fig. 8.6c), as
described in Section 7.2 of Chapter 7. The previous studies have
reported that one helical turn of amylose is composed of six repeating
glucose units when the linear guest molecules of small cross-sectional
area are included. However, it has been known that amylose can also
include bulky branched alcohols such as isopropyl alcohol, isobutyl
alcohol, and
q
= 12-13
°
and 19-20
°
-butyl alcohol to form the corresponding inclusion
complexes with the longer helix. Indeed, the XRD patterns of these
inclusion complexes, which showed the diffraction peaks at lower
angles, i.e., 2
tert
q
equal to 11-12
°
and 18-19
°
, than those observed
Figure 8.6
XRD patterns of amylose (a), PLLA (b), amylose-PTHF
inclusion complex (c), and the product obtained by vine-
twining polymerization in the presence of PLLA (d).
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