Orientation glassy polymer transport

Transport Properties. Sorption and transport properties are highly dependent on the post-vitrification history of glassy polymers (77) hence one would expect parameters such as physical aging, antiplasticization and amorphous orientation to affect transport properties. The reduction in diffusivity and permeability due to aging, orientation, and antiplasticization can be modeled via entropy or fi ee volume arguments (77). In addition, diffusive jumps of penetrant molecules in glassy polymers can be affected by (facilitated by) the segmental mobility that is manifested in sub-Tg relaxations 78),... 

Oriontation-Induced Effects. Orientation and combined heat and orientation processing affect the transport properties of glassy polymers. Especially when crystallites are present, the effects can become surprisingly large. As noted for rubbery semicrystalline materials, the obvious improvements in barrier properties associated with organization of lamellar crystalline domains with their platelets perpendicular to the direction of penetrant flow can produce significant... 

---