ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
A series of a segmented copolymer, poly(4,4′-dioxy-2,2′-dimethyl-azoxybenzene dodecanedioyl)-co-polyoxyethylene 400 (PMABD-co-POE) was prepared; the average chain lengths n, of the PMABD studied are 8.1 to 20.6. The thermotropic properties and the mesophase texture of the segmented copolymers were elucidated as functions of n using a differential scanning calorimeter and a polarized optical microscope with a hot stage. The results show that the incorporation of POE with PMABD decreases the intermolecular interaction force and changes the chain flexibility. The nematic droplets obtained near the isotropic temperature all exhibited a twisted bipolar configuration. Also, in the undercooling process, the nematic textures obtained before crystallizing varied with n. The copolymers containing n ≥ 17, like PMABD, develop a Schlieren texture, whereas those containing n 〈 17 develop a distorted-stripe conformation. A possible mechanism for interpretation of the obtained results has been proposed. © 1995 John Wiley & Sons, Inc.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1995.070550809
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