Mechanical properties of oriented emeraldine base polyaniline

The mechanical properties of high molecular weight (~ 130 000 Daltons) emeraldine base have been investigated as a function of elongation. The tensile strength is found to increase by almost one order of magnitude for samples stretched to 500% elongation compared to as-cast samples. The behaviour of breaking strain and Young modulus is essentially independent of elongation above ~300%. This behaviour has been interpreted in terms of crystalline fraction, as evaluated from X-ray diffraction measurements.