ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The paper describes synthesis and characterization of some new side-chain liquid crystalline polymers (SCLCP) obtained by homo- and copolymerization of fumarates with two mesogenic groups per unit. The homopolymerization of spacerless bis[4-(4-butoxy-benzoyloxy)phenyl] fumarate (1) did not take place due to steric hindrance of the propagation reaction by the bulky phenyl benzoate groups. The radically induced polymerization of the fumarates with spacer between fumaric unit and the mesogenic groups was performed in bulk. At the polymerization temperature the monomers were isotropic. During polymerization the mixtures became turbid due to phase separation of the isotropic monomer and the resulting polymerization products which formed a liquid crystalline (lc) phase. The molecular weights of the obtained homopolymers were relatively low and depended on spacer length. Transfer reactions to the monomer occurred to a considerable extent. The homopolymers showed an enantiotropic SA phase. This was confirmed by X-ray measurements. A model for the arrangement of the polymer backbones in the smectic phase is given. Copolymerization of bis{6-[4-(4-butoxybenzoyloxy)benzoyloxy]hexyl} fumarate (4) with styrene yielded copolymers 6 with different percentages of styrene. All copolymers formed an enantiotropic SA phase. With increasing percentage of styrene the transition to the isotropic state was shifted toward lower temperatures.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1995.021961020
