ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
3,3-Bis(4-cyano-4′-biphenylyloxymethyl)oxetane was prepared by reaction of 3,3-bis-(chloromethyl)oxetane with the sodium salt of 4-cyano-4′-hydroxybiphenyl. With highly purified dichloromethane, single crystals could be prepared. The X-ray patterns could be indexed in terms of a monoclinic cell a = 13,87 Å, b = 14,74 Å, c = 13,91 Å and β = 118,68°. Some experiments were carried out to determine the cationic polymerization behavior of this oxetane. The initiating system BF3 ċ Et2O/dichloromethane was used and it was shown that unusually high initiator concentrations were necessary to observe polymerization. By means of steric exclusion chromatography and NMR spectroscopy, the formation of cyclic oligomers was evidenced. Upon heating, all the polymers showed a nematic phase. Some preliminary Corona poling experiments were performed and the second harmonic generation coefficients d31 and d33 were measured. It was shown that one can gain in net polar ordering by starting with a liquid crystalline system. The ratio d33/d31 was found to be much larger than 3 in agreement with the molecular statistical models for electric field poling of liquid crystals.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1996.021971112
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