RADIATION-THERMAL MODIFICATION OF THE STR UCTURE OF POLYACRYLONITRILE

The effect of gamma-irradiation on the structure of PAN fibers and the laws of its transformation during the subsequent thermal treatment wa s studied. It it shown that irradiation modifies the initial structure of PAN so as to increase the rate of oxidative stabilization and decr ease the exothermal effect due to cyclization. The temperature of alph a(c)-transition in PAN decreases with the absorbed dose of gamma-radia tion, which results in a lower temperature of the onset of chemical tr ansformations in the polymer chain.