DIELECTRIC-RELAXATION IN THE ODD-NUMBERED POLYAMIDES - NYLON 7-7 AND NYLON 11

Odd-numbered polyamides have dipoles with components that point in the same direction in the planar zigzag conformation (rather than alternating as in the even-numbered polyamides). An investigation of the dielectric properties of two odd nylons was undertaken in the reported experiments to see if dipole correlation resulting from this effect could be detected. It was found that the dielectric constant and relaxation strength associated with the alpha loss process (amorphous phase glass-rubber relaxation) when normalized for dipole concentration was indeed markedly higher in the odd nylons. The effect of uniaxial orientation induced by solid-state extrusion on the isotropy of the dielectric properties was also studied. The anisotropy in relaxation strength can be explained by a composite material effect resulting from parallel stacking of crystal lamellas and interlamellar amorphous material and without invoking any anisotropy in the amorphous-phase dielectric strength.