Mechanical and electrical properties of polyacetylene films oriented by tensile drawing

Abstract

An improved technique was developed for tensile drawing of polyacetylene films prepared by the non-solvent polymerization method of Akagi et al.; draw ratios as high as 15 were obtained. Tensile drawing and the associated orientation resulted in major improvement of both the mechanical properties and the electrical conductivity (after doping). Maximum values for the modulus and tensile strength were 50 GPa and 0.9 GPa, respectively. The electrical conductivities of highly drawn thin films, doped with iodine, along the orientation direction reached values at room temperature of up to 3 × 10 4 S cm −1, with an anisotropy, σ ∥ σ ⊥ > 250 . Both Young's modulus and the tenacity decreased upon doping, typically by a factor of about 4–5, which is indicative of reduced intersegmental interaction. The results demonstrate that the electrical conductivity increases linearly with the modulus and tensile strength, with polymer chain orientation as the implicit variable.