1Russian Academy of Sciences 2Russian Academy of Sciences 3Russian Academy of Sciences 4Russian Academy of Sciences 5Russian Academy of Sciences 6Russian Academy of Sciences
The structural transformationss of oriented poly(vinyl alcohol) (PVA) fbers impregnated with potassium bisulfate (PBS) were studied in detail on the way from PVA precursor fbers till carbonized at a temperature of 1000 °C fbers. It has been shown that the impregnation of PVA fbers with a sulfur-containing compound (PBS) is an efcient technique to decrease the thermoplasticity of PVA fbers during heat treatment at high temperatures in air and argon and contributes to a high yield of coke residue after heat treatment up to 1000 °C. TMA, TGA, DSC, mass spectrometry, FTIR, Raman spectros�copy, SEM, WAXS and SAXS were used to study the structural transformations of oriented PVA fbers impregnated with PBS at the stages of their preliminary thermal stabilization (215 °C), thermal stabilization (215–400 °C) and carbonization (400–1000 °C). A reaction scheme has been proposed that fully describes carbonization chemistry in the entire studied temperature range. The processing temperature of 215 °C was found to be optimal for preliminary thermal stabilization of PVA fbers impregnated with PBS. The heat treatment in an inert medium can be recommended as the optimal for thermal stabilization of fbers impregnated with PBS. The characteristics of the carbonized PVA fbers, such as strength, modulus and electrical conductivity, were close to the characteristics of commercial cellulose-based carbon fbers yarns.