Structural and conductivity changes during the pyrolysis of polyaniline base

Polyaniline base has been exposed to various temperatures between 100 degrees C and 1000 degrees C for 2 h in air. The mass loss has increased with increasing temperature. FTIR and Raman spectroscopies show the gradual destruction of the PANI structure, the possible formation of intermediate oxime and nitrile groups, and the final conversion to graphitic material. The elemental analysis confirmed the dehydrogenation while the content of nitrogen was nearly constant even after treatment at 800 degrees C. The conductivity of PANI base, 10(-8) S cm(-1), increased to similar to 10(-4) S cm(-1) after treatment at 1000 degrees C most of the products, however, were non-conducting. Another series of experiments involved the polyaniline base heated at 500 degrees C for 1-8 h. The studies were performed in connection with the potential flame-retardant application of polyaniline. (c) 2005 Elsevier Ltd. All rights reserved.