Premium
Synthesis and characterization of polyoxetanes containing 4‐cyanobiphenyl‐based side groups for nonlinear optical applications, 2. Synthesis, characterization and polymerization of 3,3‐bis(4‐cyano‐4′‐biphenylyloxymethyl)oxetane
Author(s) -
Guichard Bertrand,
Poirier Véronique,
Noël Claudine,
Reyx Danièle,
Le Borgne Alain,
Leblanc Marc,
Large Maryanne,
Kajzar François
Publication year - 1996
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1996.021971112
Subject(s) - oxetane , polymerization , dichloromethane , cationic polymerization , polymer chemistry , ring opening polymerization , chemistry , polymer , liquid crystal , materials science , crystallography , organic chemistry , optoelectronics , solvent
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 BF 3 ċ Et 2 O/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 d 31 and d 33 were measured. It was shown that one can gain in net polar ordering by starting with a liquid crystalline system. The ratio d 33 / d 31 was found to be much larger than 3 in agreement with the molecular statistical models for electric field poling of liquid crystals.