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

PMMA films in the high global chain orientation and nearly random segmental orientation (GOLR) state were prepared by uni-axially drawing at temperatures 20-30°C above its glass transition temperature, T_g, and their isotropic and anisotropic properties were studied. Experimental results show that this kind of amorphous state, the GOLR state, is nearly isotropic in optical birefringence, IR-dichroism and X-ray diffraction patterns, but is very anisotropic in behaviors of thermal expansion, solvent-swelling and stress-strain.