Cross-linked polyacrylonitrile prepared by radiation-induced polymerization technique

Cross-linked polyacrylonitrile PAN granules were prepared at ambient temperature by gamma-rays at a constant dose rate of 8.5 kGy/h. It was found that the rate of polymerization was linear with the radiation dose at the initial stage of polymerization, and then, at high conversion, it tends to level off above 35 kGy. Cross-linking of PAN is accompanied simultaneously with the polymerization process at high energy radiation. Characterizations of the cross-linked PAN prepared at different radiation doses were investigated by FT-IR, XRD, DSC, and TGA analysis. The appearance of an IR band at 1670 cm(-1) confirmed the cross-linking of PAN via nitrile groups. The original crystal lattice and the entropy of melting DeltaS(m) did not change significantly at high radiation doses.