Effects of gamma ray irradiation on poly(acrylonitrile-co-methyl acrylate) fibers.

Gamma ray irradiation on PAN fibers did bring some benefits for the successive stabilization, however, it is still unclear about the structure of crosslinked bonds, effects of atmosphere and chain scission as well as initiation of cyclization. In this work, PAN fiber as well as a PAN solution was irradiated under different atmospheres. The structure of crosslinked bonds, molecular weights and thermal reactivity were analyzed. It is discovered that gamma ray irradiation on PAN brought chains crosslinking and scission as long as cyclization. The large amount of crosslinked bonds were discovered to be –C N–N C–, while oxygen inhibited nitriles crosslinking. The crosslinking structure rather than remained radicals initiated cyclization during thermal treatment, which was broken and reproduced polyimine radicals at higher temperature. [ABSTRACT FROM AUTHOR]