Polymerization in liquid crystal. XVIII: Effect of the polyethyleneoxide main chain on the properties of polymers containing mesogenic groups in the side chain

Abstract The effect of the main chain on the mesomorphic properties was studied on the basis of the three-component thermodynamic model of polymers containing mesogenic groups in the side chain. Poly(ethylene oxide) oligomers substituted with mesogenic groups were prepared by reacting epichlorohydrin with mesogenic molecules. It was established that the glass transition temperatures of these oligomeric products were markedly reduced in comparison to polyacrylates containing the same rigid core. The relatively flexible main chain increases the clearing point relative to that of the monomer. Clearing point rises with length of the main chain. A flexible main chain suppresses the vibration of the rigid cores thus increasing the thermal stability of the mesomorphic structure. No explanation was found for the exothermic latent heat of 170 J/g observed during the first melting of the cholesteryl succinyl epoxypropionate oligomers and polymers.