DYNAMIC-MECHANICAL PROPERTIES OF SOME LIQUID-CRYSTALLINE POLYACRYLATES

The dynamic mechanical properties of some LC (nematic and smectic) pol yacrylates with biphenyl mesogens with different spacers and tails are described. From plots of G' and G'' against frequency and temperature the phase transitions could be clearly detected, in agreement with DS C analysis. Furthermore, the dynamic viscosities of the LC polyacrylat es compared with an isotropic model polymer of similar stucture showed a strong shear rate and temperature dependence. Surprisingly it was f ound that the viscosity of the LC polymers was higher in the nematic p hase than in the isotropic phase.