Surface analysis of γ-ray irradiation modified PBO fiber

Poly[p-phenylene benzobisoxazole] (PBO) fiber is treated in a solution of epichlorohydrin and acetone using γ-ray irradiation method with a increasing irradiation dose. The irradiation treatment induces a modification of the surface properties. The effects of the treatment on the chemical components, the surface free energy, and the surface roughness of the fiber are analyzed by using X-ray photoelectron spectroscopy (XPS), dynamic capillary method and atomic force microscopy (AFM), respectively. The grafting reaction between the PBO polymer and the irradiation medium-epichlorohydrin is also discussed by 1H nuclear magnetism resonance (1H NMR) analysis. The results indicate that, γ-ray irradiation technique can significantly improve the surface chemical inertness and the surface smooth of the PBO fiber by generating some active oxygen-containing, chlorine-including and nitrogen-containing groups and activating the surface of the fiber.