Polycarbonate films in the state of high global chain orientation but nearly random segmental orientation

The polycarbonate (PC) films in the high global chain orientation but nearly random segmental orientation (GOLR) state have been prepared by being uniaxially drawn at temperatures ∼20–30°C above their glass transition temperature, Tg, and then the isotropy and anisotropy in some properties of the obtained films have been studied. Experimental results presented show that this kind of amorphous state, the GOLR state, is nearly isotropic in optical birefringence, IR-dichroism and X-ray diffraction pattern, while it is very remarkably anisotropic in behaviors of thermal expansion, solvent-swelling and stress-strain.