Morphological study of conductive polyaniline/polyimide blends. I. Determination of compatibility by small-angle X-ray scattering method

Small-angle X-ray scattering patterns of polyaniline (PANI) complexes/polyi mide (PI) blends were observed in order to analyze the compatibility betwee n two components of the blends. From the experimental results, it was concl uded that the microphase separation or molecular level mixing, which was th e reflection of compatibility, was dependent on the kinds of dopant (campho rsulfonic acid (CSA) and dodecylbenzene sulfonic acid (DBSA)), PANI content and the imidization state. On account of self-assembling nature of PANI-DB SA, PANI-DBSA/poly(amic acid) (PAA) shows phase-separated morphology. On th e other hand, PANI-CSA/PAA blends exhibited well mixed and high compatible morphology. Thermal curing of these blends brought about the change of blen d morphology, which was in correlation with altered chain structure from PA A into PI, and was also a function of PANI content. It was supposed that co nversion from PAA to PI by thermal curing processes led to enhancement of c ompatibility probably due to higher interaction between two components. (C) 2001 Elsevier Science Ltd. All rights reserved.