Etude des phases isotrope, nematique et smectique de melanges de polymeres protones et en partie deuteries

Light scattering, neutron scattering and viscosity measurements on a nematic and a smectic polymethacrylate demonstrate the presence of molecularly disperse coils in solution. For the nematic polymer, toluene is a theta solvent, the behaviour familiar from conventional polymers (unperturbed coil conformation) being exhibited at the theta point. The isotropic melts likewise contain unperturbed coils; in the case of the nematic polymers, however, the coils in the melt have a radius of gyration which is about 30% smaller than that in solution at the theta point. In the liquid-crystalline phase, the mean radii of gyration in both cases are identical to the corresponding parameters in the isotro…

Etude de deux systemes differents avec de l'hydroxy-4 benzoate de phenyle comme unite mesogene. Les separateurs sont formes de 6 unites methylene et le squelette est de l'acide poly(meth)acrylique