Abstract:

Polyimide fabric was carboxylated with alkali to improve the wearability. The properties of the alkali-treated polyimide fabric were studied by X-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectrometer (FTRI), thermogravimetric analysis, thermal resistance and water-vapour resistance test and the affinity of cationic dyes. The results show that polyimide fiber can be modified effectively by alkali treatment. XPS analysis shows that a large quantity of oxygen elements are introduced to the fiber surface after alkali treatment. FTRI analysis indicated that carboxyl groups and amide acid are introduced onte the modified fiber surface. Thermal gravity analysis shows that the thermal stability of modified polyimide fabric maintained good. Thermal resistance and water-vapour resistance of polyimide fabric decreased slightly after alkali treatment. The limiting oxygen index of the treated fabric is 37%, exhibiting the excellent flame retardancy. The carboxylation modification of polyimide fabric improved the affinity of cationic dyes, resulting in improvement of equilibrium exhaustion. The adsorption isotherm of cationic dye on carboxylated polyimide fabric presents the Langmuir adsorption model.

Key words: polyimide, carboxylation, surface modification, dyeing property