Use of 5-amino-6-hydroxy-2-(p-carboxyphenyl)benzoxazole salt

A technology for p-carboxyphenyl, benzoxazole carboxylammonium salt, which is applied in the field of preparing poly-p-phenylene benzobisoxazole resin, can solve the problems of affecting the molecular weight of PBO, lack of practicability, low yield and the like, and achieves no Gas interference and safety hazards, excellent anti-oxidative stability, and high product purity

Inactive Publication Date: 2009-02-25
ZHEJIANG UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the ABA prepared by hydrogenation of formula (3) in DMF solvent also contains PBO inhibitory impurity DMF, which affects the further improvement of PBO molecular weight, making its intrinsic viscosity [η] the highest 12.5dl / g (30 ° C, MSA )
In addition, the reaction steps of preparing ABA with the formula (3) process route are many and the yield is low, and the dehydrating agent trimethylsilane polyphosphate TSPP and the hydrogenation catalyst Pd / C are expensive and consume a lot, plus The first step reaction is carried out in an organic solvent (solvent 1 is o-dichlorobenzene, solvent 2 is ethylene glycol, and DMF, etc.), organic pollution is large, the preparation cost is extremely high and lacks practicability, it is not conducive to the application of preparing PBO and it is difficult Implementation of industrialization
Therefore, the high-cost and high-difficulty preparation technology status of PBO described above has seriously hindered the preparation, expansion and application of high-performance PBO materials, and further improvement and new technology replacement are urgently needed

Method used

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  • Use of 5-amino-6-hydroxy-2-(p-carboxyphenyl)benzoxazole salt

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Embodiment 1: MAB alkaline hydrolysis synthetic ABAS

[0038] 3g Na 2 CO 3 Dissolve in 100ml of water solvent, take MAB 2.00g (98.69%, 0.0069mol) into the mixture, pass N 2 Replace the air, carry out the hydrolysis reaction at 60°C until the solution is clear, filter while it is hot, add NaHSO to the filtrate after cooling 3 The saturated aqueous solution was adjusted to pH 6.5 to precipitate precipitates, filtered, washed with ice water, and dried in vacuo to obtain 1.61 g (0.0059 mol) of the khaki crystalline product ABAS monomer, with a purity of 99.28%. Qualitative FT-IR, 13 C-NMR, 1 H-NMR attribute analysis and elemental analysis, determined to be a new monomer of salt type AB type PBO: that is, 5-amino-6-hydroxyl-2-(p-carboxyphenyl) benzoxazole carboxyammonium salt ABAS monomer, received The rate is 85.2%.

[0039] FT-IR (KBr, cm -1 ): 3334.3, 3267.8, 3146.3, 1675.8 (carboxyammonium salt absorption peak), 1618.0, 1581.3, 1466.6, 1410.7, 1380.8, 1294.0, 1178....

Embodiment 2～5

[0042] Adopt the same operation of embodiment 1, get different parameters (two kinds of alkaline substances and proportioning, different raw material purity) by the parameter scope in table 1 and test, the results are shown in table 1:

[0043] Table 1 Preparation of ABAS monomer by hydrolysis of MAB (NaHSO 3 Adjust pH 6.5 to precipitate)

[0044]

[0045] a is K 2 CO 3 The consumption (g), embodiment 4 and embodiment 5 are K 2 CO 3 Hydrolysis process

[0046] For the hydrolysis of MAB, as can be seen from the data of embodiment 2,3, adopt Na 2 CO 3 During the hydrolysis process, the MAB raw material with lower purity (88.4-94.1%) can still obtain ABAS monomer with higher purity above 96% after hydrolysis. Using K 2 CO 3 The hydrolysis process is as in Example 4, only MAB with a purity of 94.1% can obtain 98.3% ABAS. It can be seen that while MAB is hydrolyzed, the resulting monomer ABAS can be refined and purified.

Embodiment 6～8

[0048] Adopt the same operation of embodiment 1, choose Na 2 CO 3 Hydrolysis process, by NaHSO of the present invention 3 Adjust the parameter scope of pH (get different parameter pH value 6.5,7.0,7.5) to react (the embodiment 7 of pH=7.5 is as comparative example), the results are shown in Table 2:

[0049] Table 2 Effect of pH on the precipitation of ABAS monomers prepared by hydrolysis of MAB

[0050]

[0051] Wherein, the monomer that embodiment 6 adjusts pH value 7.0 makes and the ABAS infrared absorption that embodiment 1 adjusts pH 6.5 and IR figure are completely consistent; And when embodiment 7 adjusts pH value 7.5, separate out its infrared absorption of ABA monomer The IR pattern is completely different. Put the substance of this different IR pattern back into the water and then use NaHSO 3 Adjust the pH value to 6.5, and the IR pattern of the obtained monomer is completely the same as that of ABAS (see Example 8). Their infrared absorption is relatively fi...

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Abstract

The invention relates to an application of 5-amido-6-hydroxy-2-(p-carboxyl phenyl) benzoxazole carboxyl ammonium salt (ABAS) in preparing poly(p-phenylene benzobisoxazole) (PBO) resin. The prepared ABAS monomer has the advantages of containing no polymerization inhibitors (such as DMF, DMAc and DMSO and other solvent residues) which affect the condensation polymerization of the ABA for preparing the PBO, good oxidation resistance and thermal stability, and realizing polycondensation with equivalent proportion to further enhance the PBO molecular weight and reduce the polymerization time, and the like, and the application can be developed into a new technology for implementing the PBO resin and the fiber industrialization at low cost.

Description

(1) Technical field [0001] The present invention relates to a kind of 5-amino-6-hydroxyl-2-(p-carboxyphenyl) benzoxazole carboxyammonium salt (ABAS), its synthesis method and its use in the preparation of poly-p-phenylene benzobisoxazole (PBO ) application in resin. (2) Background technology [0002] PBO is the abbreviation of cis-poly(p-phenylene-2,6-benzobisoxazole), which is the most organic and inorganic fiber by polymer liquid crystal spinning technology. High Performance Fiber - Zylon. [0003] Research so far, Japan Toyobo (Toyobo) company patent (patent open 2000-38371) under high shear conditions through (1) formula by 4,6-diaminoresorcinol hydrochloride (DAR) and hydroquinone Formic acid (TPA) polycondensation reaction to obtain PBO resin: [0004] [0005] Although the obtained Zylon-HM type PBO fiber has exhibited very excellent physical, chemical and mechanical properties, its production equipment requirements are very high, and the process condition contr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G73/22
Inventor 金宁人张燕峰刘晓峰张建庭王小辉宫经会王学杰
Owner ZHEJIANG UNIV OF TECH
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