Ultraviolet resistance modification of poly(p‐phenylene‐1,3,4‐oxadiazole) and poly(p‐phenylene terephthalamide) fibers with polyhedral oligomeric silsesquioxane

Abstract

Octa-ammonium chloride salt of polyhedral oligomeric silsesquioxane (POSS) was synthesized by a hydrolysis reaction and introduced into poly(p-phenylene-1,3,4-oxadiazole) (p-POD) and poly(p-phenylene terephthalamide) (PPTA) fibers by a finishing method to enhance the UV resistance. The effects of the POSS concentration, treatment temperature, and time on the tensile strength of the fibers were investigated. The surface morphology, mechanical properties, crystallinity, degree of orientation of fibers, and intrinsic viscosity of the polymer solution were characterized in detail. The results indicate that the tensile strength retention and intrinsic viscosity retention of the fibers treated with POSS were much higher than those of the untreated fibers after the same accelerated irradiation time; this demonstrated that this treatment method was feasible. We also found that the efficacy of the protection provided by POSS was more beneficial to p-POD than PPTA because of the different structure.

Growing Nano-SiO2 on the Surface of Aramid Fibers Assisted by Supercritical CO2 to Enhance the Thermal Stability, Interfacial Shear Strength, and UV Resistance

“…However, the abundant intermolecular hydrogen bonding and high degree of crystallinity lead to a smooth and inert surface of AFs, which hinders the adhesion strength of AFs to epoxy matrices, limiting its application in composite materials [7]. Moreover, the large amount of amide bonding in fibers is easily decomposed by UV irradiation [8,9], high temperature [10], and moisture [11]. These drawbacks constrain the working durability of AF-based composites under long-term outdoor conditions [12].…”

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.…”

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

“…And in our previous research, the octa‐ammonium chloride salt of POSS, as an anti‐UV agent, was used to treat p ‐POD and PPTA fibers. The tensile strength retention of the treated p ‐POD and poly( p ‐phenylene terephthalamide) (PPTA) fibers was increased about 83% and 74%, respectively, after UV radiation for 72 h . But the washing fastness of the treated samples was very poor.…”