Abstract
The permeability coefficients of gases were measured for the polyester films obtained by simultaneous biaxial stretching. The relation between the permeability coefficients of gases and the internal fine structure of polymer film was discussed.
The permeability coefficients decreased with increasing stretching ratio more drastically than the case of uniaxially stretched films, suggesting that the orientation or order of molecular chain in the biaxially stretched polymer film increased more than that of uniaxially stretched polymer film. The permeability coefficients, Pa, of gases in the amorphous region pf polymer were discussed along the same lines as given in our preceding report.
