RELATION OF GAS-PERMEABILITY WITH STRUCTURE OF AROMATIC POLYIMIDES .2.

We investigated relations between diffusivities on polyimides and phys ical parameters with mobilities of segments and examined viscoelastici ty of polyimides on introducing the parameter as an index of mobilitie s of polymer chains. Each relaxation temperature of viscoelasticities on polyimide films having ordered regions was almost the same as that on the amorphous states. The CF, group as a substituent showed the sim ilar effect to that of CH, group in elastic relaxation. The storage mo dulus was correlated well with the gas diffusivity. And in the case th at relations between the diffusion coefficients and cohesive energy de nsities (CED) which were introduced as an index of cohesiveness of seg ments, the relation between CED and the gas diffusivities showed a goo d correlation. Mobilities of segments affected strongly the gas diffus ivities even in the glassy polymers such as polyimides.