Phenomenology and mechanisms of unidimensional stress‐dependent micromolecular transport in a stiff‐chain polymer. II. Uniaxially oriented cellulose acetate

The study of micromolecular transport in cellulose acetate film reported previously is here extended by investigation of the effect of different degrees of semipermanent uniaxial macromolecular orientation, produced by prestretching the film under suitable conditions. The changes noted in penetration rate and kinetics and in birefringence, tracer microdensitometry, and microinterferometry profiles for penetration along and across the axis of preferred orientation, are reported in detail and their implications in terms of the transport mechanism are discussed.