Improving the UV resistance of aromatic poly(1,3,4‐oxadiazole) fiber using the disperse dye modified with octavinyl POSS . Part 2: Fixing form of dye and UV resistance ability

Disperse Red 60 modified with octavinyl polyhedral oligomeric silsesquioxanes (POSS) was used to color poly(p‐phenylene‐1,3,4‐oxadiazoles) (p‐POD) fiber. The dyed p‐POD fiber was given high UV resistance and excellent color strength (K/S value) simultaneously. And the effects of the UV irradiation time on the K/S values and the strength retention of dyed fiber were investigated. The results indicated that the modified dye (1:3) molecules can easily be adsorbed on fiber surface and diffuse into fiber, whose fixing form on the fiber surface is a semiembedded type. Meanwhile, the surface morphology, the aggregation structure, the thermal property, the color fastness, and anti‐UV durability of the dyed p‐POD fiber were characterized. After UV accelerated aging, the macroscopic and microscopic structures of the dyed p‐POD fiber can well be maintained and the color fastness is also satisfactory. Meanwhile, this method also solves the problem of poor anti‐UV durability of the modified fiber with the previous processes.