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Preparation of poly-p-phenylene benzodioxazole fibers

A benzobisoxazole and poly-p-phenylene technology is applied in the field of preparation of poly-p-phenylene benzobisoxazole fibers, and can solve the problems of poor fluidity, difficulty in increasing the molecular weight of PBO, loss of mixing function of a stirrer, and the like. Avoid hygroscopic effects

Inactive Publication Date: 2005-07-27
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the later stage of polymerization, the viscosity of the polymerization system rises rapidly, and the viscosity of the PBO / PPA solution is generally above 2000Pa·s (180°C) depending on the molecular weight of PBO, which will lead to the following problems: First, the polymerization system will stick together and stick On the agitator, the agitator loses its mixing function. Although the use of a special agitator (patent: ZL 02294359.5) can partially solve this problem, it is still difficult to increase the molecular weight of PBO in this way; the second is that the polymerization system has high viscosity and poor fluidity. And it cannot be in contact with air (otherwise PPA will absorb moisture), so it is difficult to transfer the polymer material to the screw extruder for spinning

Method used

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  • Preparation of poly-p-phenylene benzodioxazole fibers

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Add 225.8g of 4,6-diaminoresorcinol hydrochloride (DAR), 1045.6g of P 2 o 5 Concentration is 80wt% polyphosphoric acid (PPA), 157.59g terephthalic acid (TPA, 90% of total charge) and 539g of P 2 o 5 , Seal the reactor.

[0026] Raise the temperature of the reaction materials in the reactor to 50°C and keep for 1 hour to make the materials mix initially, then slowly raise the temperature to 65°C and keep for 1 hour to further dissolve the materials.

[0027] Fill the reactor with dry high-purity nitrogen to make the pressure in the reactor reach 1.0MPa, and at the same time raise the temperature to 120°C, keep it for 7 hours, open the pressure relief valve, and remove the pressure in the reactor. Then heat up the reaction material to 145°C, and react for 6 hours to completely discharge the remaining HCl until the neutral color is detected at the gas escape port with pH test paper, then remove the vacuum in the reactor, and then raise the temperature of the reaction ma...

Embodiment 2

[0032] Add 225.8g of 4,6-diaminoresorcinol hydrochloride (DAR), 1045.6g of P 2 o 5 Concentration is 80wt% polyphosphoric acid (PPA), 162.84g terephthalic acid (TPA, 93% of total charge) and 539g of P 2 o 5 , Seal the reactor.

[0033]Raise the temperature of the reaction materials in the reactor to 50°C and keep for 1 hour to make the materials mix initially, then slowly raise the temperature to 65°C and keep for 1 hour to further dissolve the materials.

[0034] Fill the reactor with dry high-purity nitrogen to make the pressure in the reactor reach 1.0MPa, and at the same time raise the temperature to 120°C, keep it for 7 hours, open the pressure relief valve, and remove the pressure in the reactor. Then heat up the reaction material to 145°C, and react for 6 hours to completely discharge the remaining HCl until the neutral color is detected at the gas escape port with pH test paper, then remove the vacuum in the reactor, and then raise the temperature of the reaction mat...

Embodiment 3

[0039] Add 225.8g of 4,6-diaminoresorcinol hydrochloride (DAR), 1045.6g of P 2 o 5 Concentration is 80wt% polyphosphoric acid (PPA), 168.1g terephthalic acid (TPA, 96% of total charge) and 539g of P 2 o 5 , Seal the reactor.

[0040] Raise the temperature of the reaction materials in the reactor to 50°C and keep for 1 hour to make the materials mix initially, then slowly raise the temperature to 65°C and keep for 1 hour to further dissolve the materials.

[0041] Fill the reactor with dry high-purity nitrogen to make the pressure in the reactor reach 1.0MPa, and at the same time raise the temperature to 120°C, keep it for 7 hours, open the pressure relief valve, and remove the pressure in the reactor. Then heat up the reaction material to 145°C, and react for 6 hours to completely discharge the remaining HCl until the neutral color is detected at the gas escape port with pH test paper, then remove the vacuum in the reactor, and then raise the temperature of the reaction mat...

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Abstract

A process for preparing poly-p-phenylene benzdioxazole (PBO) fibres includes such steps as prepolymerizing by adding part (90-99%) of terephthalic acid to obtain low-viscosity prepolymer, mixing the rest of terephthalic acid with polyphosphoric acid (PPA) to obtain slurry, mixing it with prepolymer and polycondensating in a dual-screw extruder, and liquid-crystal spinning.

Description

technical field [0001] The invention relates to a preparation method of poly-p-phenylene benzobisoxazole (PBO) fiber. Background technique [0002] Poly-p-phenylene benzobisoxazole (PBO) fiber was invented by the U.S. Air Force Materials Laboratory, Dow Chemical Company participated in the development, and Japan Toyobo successfully realized industrial production in the 1990s. Its trade name is "Zylon". Zylon has a tensile strength of 5.8GPa and a tensile modulus of 300GPa, which are twice that of aramid fiber; in addition, Zylon also has excellent thermal stability (thermal decomposition temperature as high as 650°C) and flame retardancy (LOI=68 ). Therefore, PBO fiber has important application value in aerospace, national defense, transportation, sports equipment, construction, high temperature protection and other fields, and has an irreplaceable role for other materials. Especially since mankind entered the information age, the competition among countries in terms of co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F6/74
Inventor 李光杨胜林江建明金俊弘
Owner DONGHUA UNIV
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