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Method for producing PBO (poly-p-phenylene-benzobisoxazole) fibers

A technology of benzobisoxazole and poly-p-phenylene is applied in the field of preparation of poly-p-phenylene benzobisoxazole fibers, and can solve the problems of long reaction time, low solubility in terephthalic acid, long time for removing hydrogen chloride, etc. problem, to achieve the effect of speeding up the reaction speed, conducive to the molecular weight of the polymer, and high probability of direct collision

Active Publication Date: 2015-08-26
杨拯
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] According to the above patents, there are the following difficulties in the preparation process of PBO: (1) The solubility of terephthalic acid in polyphosphoric acid is very low, so that the polymerization process needs more Long reaction time, usually more than 24 hours, some even more than 100 hours; (2) The polyphosphoric acid system has a very high viscosity, and the time to remove hydrogen chloride is too long; (3) There is a patent for terephthalic acid in polyphosphoric acid The problem of low solubility is proposed to use other raw materials such as terephthaloyl chloride to synthesize, but the process has increased a lot, and the increase in the process will inevitably increase the cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A) Preparation of pre-polymerization solution: 8.99 kg of terephthalic acid and 11.53 kg of 4,6-diaminoresorcinol hydrochloride were fully mixed in a nitrogen-filled ribbon mixer to form a mixed powder. Add 20kg of polyphosphoric acid solution with a mass percentage of phosphorus pentoxide of 73% into the reactor, and add the above-mentioned mixed powder together, connect the outlet of the lower part of the reactor to a multi-stage emulsification pump, and keep the temperature of the reactor at 40°C , grind and disperse continuously through multi-stage emulsification pump and vacuumize to remove hydrogen chloride for 180min at the same time. After removing the hydrogen chloride, continue to add 33kg of phosphorus pentoxide to the reaction kettle so that the mass percentage of phosphorus pentoxide in the polyphosphoric acid is adjusted to 83%, fully stir and keep the temperature at 180°C, and at the same time vacuumize and keep it for 270min, After the prepolymerization...

Embodiment 2

[0027] A) Preparation of pre-polymerization solution: 8.99 kg of terephthalic acid and 11.53 kg of 4,6-diaminoresorcinol hydrochloride were fully mixed in an argon-filled ribbon mixer to form a mixed powder. Add 14kg of polyphosphoric acid solution with a mass percentage of phosphorus pentoxide of 73% into the reactor, and add the above-mentioned mixed powder together. The grinder continuously circulates to grind and disperse while vacuuming to remove hydrogen chloride for 180 minutes. After removing the hydrogen chloride, continue to add 30kg of phosphorus pentoxide to the reaction kettle so that the mass percentage of phosphorus pentoxide in the polyphosphoric acid is adjusted to 84%, stir well and keep the temperature at 160°C, and at the same time vacuumize and keep it for 180min, After the prepolymerization reaction is completed, the prepolymerization solution is transferred to the prepolymerization solution storage tank, and the polymer mass percentage in the prepolymer...

Embodiment 3

[0030] A) Preparation of pre-polymerization solution: 8.99 kg of terephthalic acid and 11.53 kg of 4,6-diaminoresorcinol hydrochloride were fully mixed in a nitrogen-filled ribbon mixer to form a mixed powder. Add 12kg of polyphosphoric acid solution with a mass percentage of phosphorus pentoxide of 74% into the reactor, and add the above-mentioned mixed powder together. Grind and disperse continuously through a twin-screw pump while vacuuming to remove hydrogen chloride for 60 minutes. After removing the hydrogen chloride, continue to add 28kg of phosphorus pentoxide to the reaction kettle so that the mass percentage of phosphorus pentoxide in the polyphosphoric acid is adjusted to 84%, fully stir and keep the temperature at 150°C, and at the same time vacuumize and keep it for 180min, After the prepolymerization reaction is completed, the prepolymerization solution is transferred to the prepolymerization solution storage tank, and the polymer mass percentage in the prepolym...

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Abstract

The invention discloses a method for producing PBO (poly-p-phenylene-benzobisoxazole) fibers and belongs to the technical field of high-performance fibers. The method comprises steps as follows: firstly, terephthalic acid and 4,6-diaminoresorcinol dihydrochloride are mixed, then mixed powder and polyphosphoric acid with the content of phosphorus pentoxide ranging from 73% to 76% are added to a reaction kettle to be stirred, continuous and circulating shearing, dispersion and grinding are performed, the phosphorus pentoxide is added to a solution with hydrogen chloride removed, then a prepolymerization reaction is performed, and continuous vacuum pumping is performed; an obtained prepolymerization liquid is pumped into a twin-screw extruder, meanwhile, polyphosphoric acid with the content of phosphorus pentoxide ranging from 83% to 86% passes through a metering pump, materials have a post-polymerization reaction in the twin-screw extruder to form spinning melt, the spinning melt is sent into a spinning machine, enters a coagulating bath for coagulation and then is washed with deionized water, washed with alkali and dried, and finally, winding formation is performed. The requirement of the polymerization reaction for the monomer mole ratio is ensured; the speed of the prepolymerization reaction is increased; quick removal of the hydrogen chloride is facilitated; and increase of polymer molecular weight is facilitated.

Description

technical field [0001] The invention belongs to the technical field of high-performance fibers, and in particular relates to a preparation method of poly-p-phenylenebenzobisoxazole fibers. Background technique [0002] Poly-p-phenylene-benzobisoxazole fiber (Poly-p-phenylene-benzobisoxazole, referred to as PBO), its macromolecular main chain is a conjugated rigid polymer with an aromatic heterocyclic structure. Due to the high orientation of the molecular structure, it It is easy to form fibers, and the constituent units of the fibers and the microfibers and fiber elements are also highly oriented, which makes the polymer fibers highly oriented. Combined with the high bonding force of its aromatic and heterocyclic rings, PBO has particularly outstanding advantages in mechanics and high temperature resistance. performance. It has important applications in aerospace, national defense, transportation, sports equipment, construction, high temperature protection and other field...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F6/74C08G73/22
Inventor 杨拯
Owner 杨拯