High performance materials from oriented plastics

Molecular orientation of polymer chains affects considerably the final properties of plastic products, such as stiffness, creep and impact resistance, barrier properties and transparency. Different orientation processes, such as solid state extrusion, die-drawing and roll-drawing are currently being investigated in order to produce parts with large dimensions. Examples include the die-drawing process for the obtention of oriented tubes and shapes, roll-drawing for flat and simple geometry profiles as well as uniaxial and biaxial solid state extrusion. These processes have been used successfully to form different materials, from polyolefins to engineering and specialty resins, and mechanical properties comparable to fiber reinforced plastics have been achieved. Solid state forming was performed in our laboratories on several polymeric materials using rolling, roll-drawing and solid state extrusion. Significant improvements in the mechanical behavior were observed and materials with tensile modulus and strength above 10 GPa and 400 MPa, respectively, were obtained. An improvement in the transverse mechanical properties was also observed for the roll-drawn polymers.