CHARACTERIZATIONS OF CRYSTALLINE-STRUCTURE AND ELECTRICAL-PROPERTIES OF PYROLYZED POLYFURFURYL ALCOHOL

Polyfurfuryl alcohol (PFA) is pyrolyzed at 600 degrees C for different lengths of heat-treatment (HT) time (0-50 h) and at different pyrolyt ic temperatures (600-850 degrees C) for 4 h. Analysis by Raman spectro scopy shows that the crystallite size of PFA pyrolyzed at 600 degrees C decreases with increasing HT time. This suggestion is supported by t he electrical conductivity measurements on PFA samples pyrolyzed at di fferent HT temperatures and at 600 degrees C for different HT times, A trend of transition from semiconductive to metallic properties is sug gested for the samples prepared above 850 degrees C. (C) 1997 American Institute of Physics.