Comparison of phase separation structures in blends of polyaniline/camphor sulfonic acid and nylons 6 and 12

Small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) techniques were used to characterize the PANI-0.5-HCSA morphology in nylon blends. SAXS shows that the polyaniline (PANI) salt resides mainly in the inter-spherulitic region of the nylon host. The morphology of the conducting salt component was analyzed by SANS data and was treated by two standard models: Debye—Bueche (D—B) and inverse power law (IPL). Due to deviations in the linear curve fitting over a large scattering range, neither the D—B nor the IPL model could be used to characterize the size and shape of all PANI-0.5-HCSA/nylon blend systems. At 3 vol.% PANI loading concentrations, the D—B model suggested salt domains with characteristic lengths of 22 nm for the nylon 12 blend. This differs in the blend reported with nylon 6 where the IPL model indicated a fractal geometry. As salt concentrations are increased in both nylons, the structures are observed to change, but there is no simple structural model that provides a suitable basis for comparison.