Improving the UV resistance of aromatic poly(l,3,4‐oxadiazole) fiber using a disperse dye modified with octavinyl POSS. Part 1: Preparation of dye and dyeing

Abstract

Modified dyes were obtained by grafting of disperse dyes with octavinyl polyhedral oligomeric silsesquioxanes (POSS) using a Friedel-Crafts alkylation reaction and using different ratios of POSS and the original disperse dye. The modified dyes are used to dye aromatic poly(l,3,4-oxadiazole) (p-POD) fiber to improve its UV resistance. Then the structure of the modified dye is characterized by Fourier transform infrared spectroscopy and NMR, and the effects of the structure of the modified dye and the dyeing conditions on the UV resistance and color strength (K/S value) of the dyed samples are investigated. The results indicated that the UV adsorption peaks of the modified dye solutions are located at the specified UV wavelengths. The UV resistance of the p-POD fiber dyed with the modified dye (1:3) can be effectively improved, and the dyed p-POD fiber can obtain a higher K/S value simultaneously. During the dyeing process, increasing the dyeing temperature and prolonging the dyeing time are both beneficial in improving the anti-UV ability of the dyed p-POD fiber; these changes can effectively promote the fixation of dye molecules into p-POD fibers due to stimulating the motion of dye molecules and p-POD macromolecules.

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

“…In addition to definitely pointed out, the modified dye refers the modified dye (1:3) in this article. The dyeing process of the samples is according to the previous paper …”

Poly‐p‐phenylene terephthamide modified poly(1,3,4‐oxadiazole) fibers with superior ultraviolet resistance

“…Yang and Mao tried to reduce the UV absorption of POD to fabricate acceptable photostable POD fibers through surface treatment. [18][19][20][21] Nevertheless, the surface treatment is challenging to modify POD on a large scale, and the treated layer is always vulnerable. Additionally, blending light stabilizers is regarded as an easy method, but POD needs to be dissolved in fuming sulfuric acid for wet-spinning, causing most of the light stabilizers to be destroyed.…”

“…To date, based on the mechanism of reducing UV light absorption, many anti-UV aging modification methods have been reported. [17][18][19][20][21][22][23][40][41][42][43][44] However, only very limited attention has been paid to the potential of the PET mechanism for improving UV-aging resistance. Herein, inspired by the quenching effect of PET reaction on fluorophore documented before, [45][46][47][48] we proposed a facile, low-cost yet efficient method by blending a small amount of poly-p-phenylene terephthamide (PPTA) into POD chains to obtain POD/PPTA composite fibers.…”

“…However, the high cost of ADA makes it difficult for practical applications. Yang and Mao tried to reduce the UV absorption of POD to fabricate acceptable photostable POD fibers through surface treatment 18–21 . Nevertheless, the surface treatment is challenging to modify POD on a large scale, and the treated layer is always vulnerable.…”

Structure and properties of halogen-free flame retardant and phosphorus-containing aromatic poly(1,3,4-oxadiazole)s fiber

“…However, p-POD ber has some obvious disadvantages, particularly poor ultraviolet (UV) light resistance and ame retardancy, which greatly limit its development and the scope of its applications. In the past few years, considerable efforts were made to study its UV light resistance, including the effect of UV irradiation and the mechanisms of photodegradation, 1,2 the methods to improve its UV resistance, [3][4][5][6][7][8][9] the function of oxygen during the photodegradation process 10 and so on. However, the disadvantage of the poor ame resistance of the POD bers did not attract much attention.…”