ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The phase behaviour of cellulose tricarbanilate (CTC) in ethyl methyl ketone (MEK) solutions was studied in the concentration range of 0,2 - 0,8 g/ml as a function of the temperature. By analyzing the textures in the polarizing microscope and by differential scanning calorimetry experiments several different phase transitions and mesophases were detected. At a concentration below 0,6 g/ml CTC in MEK, phase transitions were observed from the crystalline through a liquid crystalline (cholesteric) to the isotropic state. At concentrations higher than 0,6 g/ml, a different behaviour of the CTC solutions was detected and several transitions were found, but only the cholesteric-isotropic transition could be identified. The concentration dependence of the cholesteric-isotropic transitions was determined over the whole concentration range. The conformation of the CTC molecule was studied and a stiff, almost cylindrically shaped 3/2 helix with a repeat distance of 15,25 Å is proposed.
Additional Material:
14 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1983.021840818
Permalink