화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.287, 57-57, 1996
Liquid-Crystalline Polyfumarates .1. Synthesis and Characterization of Fumarates with 2 Mesogenic Groups
The synthesis of fumarates with two mesogenic groups is described. The basic concept of synthesis is the coupling of phenyl benzoate derivatives containing free hydroxyl groups with fumaroyl chloride in the last step. The spacerless di-[4-(4-n-butoxybenzoyloxy)phenyl] fumarate 3 and some di-{omega[4(4-n-butoxybenzoyloxy)benzoyloxy]alkyl} fumarates 7 with increasing number of alkyl groups in the spacer, between C-2 and C-8, were synthesized. The phase behaviour of the (omega-hydroxyalkyl)-4-(4-n-butoxybenzoyloxy)-benzoylozoates 6 and the Fumarares 3 and 7 was investigated by polarizing microscopy and differential scanning calorimetry (DSC). The spacerless fumarate 3 shows a liquid crystalline (lc) phase above the melting point up to decomposition. The mesomorphism of hydroxyl-terminated precursors 6 depends on spacer length. Whereas the compounds with the shortest and the longest spacer only show a monotropic lc phase the others form an enantiotropic smectic one. Among the Fumarates 7 only those with C-4 and C-6 spacer exhibit a monotropic smectic phase. The complex melting behaviour of these fumarates is discussed. The synthesized fumarates are intended for investigations on homo- and copolymerization behavior.