Polymethylmethacrylate films in the state of high global chain orientationbut 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 temperatu res 20 similar to 30 degrees 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 i sotropic in optical birefringence, IR-dichroism and X-ray diffraction patte rns, but is very anisotropic in behaviors of thermal expansion, solvent-swe lling and stress-strain.