Process control method for PBO fiber production

Abstract

The invention discloses a process control method for PBO fiber production. PBO fiber is produced from polyphosphoric acid, phosphorus pentoxide, 4,6-diaminoresorcinol hydrochloride and terephthalic acid as raw materials by degassing, pre-polymerization, post-polymerization and spinning, the terephthalic acid is respectively poured into the three stages of raw material mixing, pre-polymerization and post-polymerization for production. In the production process, and the sum of molar amounts of the terephthalic acid injected in the three times is guaranteed to be equal to the molar amount of the4,6-diaminoresorcinol hydrochloride injected during the raw material mixing stage. According to the method, the polymerization production of the PBO fiber can be completed in the manner of multiple times of feeding of the TPA (terephthalic acid), the solution tressure of the TPA during the initial feeding is reduced, the process time of the mixing, the degassing, and the pre-polymerizing in the early stage can be shortened, and the performance of subsequent PBO fiber products can be improved.

Description

technical field [0001] The invention relates to a process control method for the production of PBO fibers, in particular to a control method for the production of poly-p-phenylenebenzobisoxazole (PBO) fiber polymerization process, and belongs to the field of special polymer material polymerization. Background technique [0002] Poly-p-phenylenebenzobisoxazole (PBO) fiber is the special organic fiber with the highest tensile strength, the highest tensile modulus, and the highest thermal stability among all high-performance organic fibers. It is known as "the super fiber of the 21st century. ". Because of its excellent comprehensive mechanical properties, it is widely used in special bridge ropes and cables, bulletproof and impact resistant materials, and is one of the important special materials in aerospace and national defense high-tech fields. [0003] In 1981, Wolfe et al. first reported the synthesis of PBO materials, which were composed of 4,6-diaminoresorcinol hydroch...

AI Technical Summary

Problems solved by technology

[0008] Since the existing PBO fiber production process adopts the method of feeding 4,6-diaminoresorcinol hydrochloride (DAR) and terephthalic acid (TPA) in one batch, although the twin-screw reactor solves the problem of post-polymerization The solution viscosity is high, but the impact of low TPA solubility on pre-polymerization and subsequent product quality is not considered. For this reason, the present invention provides a process control method for PBO fiber production, which uses TPA multiple times The feeding method is to feed in proportion to the steps of mixing, pre-polymerization and post-polymerization in the production process and cooperate to complete the polymerization production of PBO fiber, which reduces the dissolution pressure of TPA during the initial feeding and shortens the time of mixing, degassing and pre-polymerization in the early stage. Process time is beneficial to improve the performance of subsequent PBO fiber products

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