08.11.2014 Views

Modern Polymer Spect..

Modern Polymer Spect..

Modern Polymer Spect..

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

3.14 Case Studies 147<br />

OC<br />

60<br />

58<br />

57.<br />

56<br />

55.<br />

54<br />

52.<br />

50<br />

49<br />

47<br />

a.<br />

43<br />

41<br />

39<br />

36<br />

33.<br />

21<br />

Figure 3-26. Dodecylcyanobiphenyl. (a) Temperature-dependent infrared spectra in the defect<br />

mode frequency range. (b) Experimental spectroscopic evidence from difference spectroscopy that<br />

at the phase transition crystal - sniectic the conformation of the dodecyl residue changes froin all-<br />

~YLIII.F to 'liqnid-like' (the most connnon defect modes appear clearly). From sinectic to liquid phases<br />

no drastic confoiiiiational changes are observed (see text).<br />

3.14.2.2 Case 2: Liquid Crystalline <strong>Polymer</strong>s: Polyesters<br />

We consider the case of the polyiner -[(CH2)lo-00C-C~H~-00C-C6HJ-COO-<br />

CcH4-COO],- (hereafter referred as HTH-10) whose phase transitions are the following:<br />

K-S 221 "C; S-I 260°C. From the overall aiialysis of the temperature-

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!