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Magneto-orientation effects were observed for platelets of thin layered single crystals of L- and DL-dipalmitoylphosphatidylcholine (DPPC), and for single crystals of polyethylene (PE) suspended in xylene. For both L- and DL-DPPC crystals, a biaxial magneto-orientation was observed, in which both directions of hydrocarbon chain and phosphorylcholine group were directed perpendicular to the applied field direction. For PE, the hydrocarbon chain direction was oriented perpendicular to the field.From the orientational behaviour under the magnetic field, the anisotropy of diamagnetic susceptibility, the difference between susceptibilities parallel and perpendicular to the hydrocarbon chain direction, is evaluated as - 9 × 10-8 and - 1 × 10-8 emu/cm3 for L-DPPC and PE, respectively.The origin of the diamagnetic anisotropy of DPPC is briefly discussed in terms of the molecular and crystal structures.

By use of the torsional quartz crystal method, the real and imaginary parts of the complex shear mechanical impedance of several nematogenic materials were measured as functions of the temperature at frequencies ranging from 50 to 150 kHz. From the impedance, we have determined the real and imaginary parts of the complex shear viscosity, in which a remarkable pretransitional anomaly is observed in the isotropic phase near the isotropic-nematic phase transition temperature, Tc. In the nematic phase and the isotropic phase except for the vicinity of Tc, the Newtonian behaviour is observed.The behaviour of the complex shear viscosity in the isotropic phase has been analyzed by the theory of de Gennes, and it is shown that the observed behaviour can be well described by the theory.

Thermal conductivity of high-density polyethylene was measured by the steady-flow method at temperatures from 4.2 to 20°K. Results were analysed assuming two scattering processes of phonons: grain boundary scattering with a mean free path ?Gwhich is independent of phonon wave number k and intragrain scattering with a mean free path ?D=A/ak2. It was found that ?G=0.48 µ and A/a=0.51×1010cm-1for the as-received sample, and both increase with annealing. The radius of spherulite which was kept constant with annealing ranged 5 to 10 µ. ?Gis attributed to the extension of lamellar crystallite in the ab-plane. ?Dis assigned to intralamellar sub-boundaries. According to results in literature, the ratio of thermal conductivity K to specific heat C is almost constant from 1 to 3°K, where the grain boundary scattering is predominant. Since at 1°K the contribution of two-dimensional lattice waves (Lamb waves in lamellae) is more appreciable than three-dimensional ones, the above result implies that ?Gis the same for the two types of waves, which is consistent with our conclusion for ?G.

In the nematic phase near the smectic A phase, a small but finite shear elasticity was observed by shear ultrasonic measurements at frequencies around 105Hz in p-cyanobenzylidene-p'-n-octyloxyaniline. The observed apparent shear modulus was ?104cgs, or equivalently ?102poise of the imaginary part of the complex shear viscosity, at 1 K above the nematic-smectic A phase transition temperature. The observed elasticity is mainly attributable to the direct coupling of the shear flow with the smectic order parameter.

A torsional quartz crystal method was used to obtain the complex shear mechanical impedance of cholesteryl nonanoate at 150 kHz. The apparent shear modulus evaluated from the measured impedance shows a finite value of ?104cgs in the middle of the cholesteric phase. The observed shear elastic behaviour can be interpreted in terms of the existence of an apparent layer compression modulusin the cholesteric phase, which gives rise to the second sound mode similar to that in the smectic A phase.

The ultrasonic shear mechanical impedance of octyloxy cyanobiphenyl and cyanobenzylidene octyloxyaniline was measured by the torsional quartz crystal method. The measured impedance suggested a finite shear elasticity in the smectic-A phase, which was interpreted as an evidence of the existence of the finite smectic layer compression modulus giving rise to a propagating "second sound mode". From the impedance the smectic layer compression modulus was evaluated as ?107cgs for both compounds and it showed a pretransitional decrease as the nematic phase was approached.

A new method for studying the anisotropy in mechanical relaxations of oriented polymers is proposed. The method consists of measuring velocicty and attenuation of ultrasonic shear waves propagating in the normal direction to the film as a function of the angle between draw direction and wave polarization. This method can separate the orientation of crystalline phase, amorphous phase and others in the polymer, because multiple relaxations in the temperature dispersion curve are ascribed to related phases, respectively. Preliminary results for low density polyethylene and polytetrafluoroethylene at 3 and 10 MHz in temperature -60° to 40°C are presented and the deformation mechanism of polyethylene is suggested.