Preparation method of anti-ultraviolet aging polyphenylene benzodioxazole fiber

Abstract

The invention relates to a preparation method of an anti-ultraviolet aging polyphenylene benzodioxazole fiber, which comprises the following steps: adding raw materials into a prepolymerizer according to the mixing ratio, removing chlorine hydride gas at certain temperature, gradually increasing the temperature to 160-180 DEG C, carrying out reaction for 12-48h, then transferring into a twin-screw reactor for carrying out postpolymerization, obtaining PBO / PPA spinning solution which is in line with requirements, and quantitatively conveying into a spinning component by a metering pump; and extruding the PBO / PPA spinning solution by a spinneret plate at 150-200 DEG C, passing through an air gap layer of 50-300cm for stretching, then entering into a coagulation bath, passing through a washing process of 50-300m with warm water at about 30-50 DEG C after passing through the coagulation bath, drying at 70-110 DEG C, then winding at the speed of 50-200m, obtaining a PBO protofilament, continuously carrying out heat treatment at 550-650 DEG C and obtaining the high-modulus PBO fiber, wherein an anti-aging agent is added in coagulation bath solution in advance. The anti-ultraviolet aging polyphenylene benzodioxazole fiber has the advantages that the anti-aging agent is closed and retained in the fiber, thereby giving the durable anti-aging property to the fiber; and the process is simple and applicable to the industrial operation.

Description

【Technical field】 [0001] The invention relates to the technical field of polyphenylene benzobisoxazole (PBO) fiber preparation, in particular to a preparation method of ultraviolet light aging-resistant PBO fiber. 【Background technique】 [0002] Polyphenylene benzobisoxazole (PBO for short) is a rigid rod-shaped liquid crystal polymer with a full aromatic heterocycle. The PBO fiber produced by the dry jet wet spinning process has low density, high strength, high modulus and extremely high heat resistance. It is one of the high-performance fibers with the best comprehensive properties at present, and it is called the super organic fiber of the 21st century. It has broad application prospects in many fields such as aerospace and high-tech equipment. [0003] Although PBO fiber has good mechanical properties and thermal stability, when PBO fiber is exposed to ultraviolet light for a long time, the fiber strength will be greatly reduced. In September 2003, the second chance bod...

AI Technical Summary

Problems solved by technology

[0006] For PBO fibers, a large number of studies have shown that those general-purpose anti-aging agents that can improve the UV aging resistance of most polymer materials are not good for improving the UV aging resistance of PBO fibers (Walsh PJ et al. al, Journal of Applied Polymer Science, 2006, 102: 3525)

Another problem lies in the processing process: additives exist in the polymerization system as an impurity during in-situ polymerization, which will inevitably interfere with the polymerization process; The viscosity of the melt is much higher, and the inorganic nanoparticles are very easy to agglomerate, so it is difficult to realize the nano-scale dispersion of the nanoparticles in the ultra-high viscosity spinning solution; The rheological properties of liquid crystal polymers are very sensitive. Adding additives such as anti-aging agents to the spinning solution will affect the rheological properties of liquid crystal polymers, interfere with the orientation of macromolecular segments and the formation of ordered structures, and increase the difficulty of spinning , because even small defects in the structure can greatly affect the strength and modulus of the fiber