ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Side-chain liquid-crystalline polymers were synthesized using malonic acid esters with a mesogenic group (1) linked through a hexamethylene spacer and oligo(ethylene glycol) (2n) as a flexible mainchain spacer. Polymers derived from 1 with a mesogen such as p-nitrophenylazophenoxy (1a) or 4-(4′-nitrophenylvinylene)phenoxy group (1b) form stable mesophases over a wide temperature range, through the increase of chain length of 2n decreases the thermal stability of the liquid-crystalline (LC) phases. LC polymers were obtained from 1 with a mesogen with p-substituted biphenoxy groups only when 2n with shorter chain length is employed. Copolymerizations were undertaken to see the effect of monomer pairs and copolymer compositions on the phase transition behavior of the copolymers formed, using three monomer pairs, 1a and 1 with the p-methoxybiphenoxy group as the mesogen, 1a and 1b, and 1a and 1 with the p-nitrobiphenoxy group as the mesogen. The copolymers formed from the first pair display a nematic phase over a much wider temperature range than the respective homopolymers. This was ascribed to the electron donor-acceptor interaction between the two mesogens in the monomer pair.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
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