Mechanical behavior and molecular orientation of polycarbonate plates prepared by press-induced deformation

摘要

Through a uniaxial hot compression method, polycarbonate (PC) plates were self-reinforced effectively by press-induced deformation. Relationships between macroscopic mechanical properties including tensile, impact as well as viscoelastic properties, and microscopic status such as morphologies and orientation were obtained in deformed PC plates. Results showed that PC plates which were compressed at appropriate temperatures (20 degrees C-120 degrees C) obtained simultaneous enhancements in tensile strength (28%), elastic modulus (38%) and impact strength (700%), compared with the original plate. The impact fracture morphologies of deformed PC plates revealed evident ductile breakage. Wide-angle X-ray diffraction investigations were conducted to attribute mechanical behavior to molecular segment orientation, which was more sensitive to temperature. Self-reinforced mechanism was proposed to analyze the high correlation between various orientations of molecular segments and corresponding mechanical performance, explained by storage and loss moduli in dynamic mechanical analysis as supplemental verification. Press-induced deformation was proved to be a potentially effective method for the self-reinforcement treatment for PC transparent products.