KR20160060235A - The method of synthesizing fluorine-containing Polyhydroxyamides - Google Patents

Abstract

The present invention relates to a synthesis method of polyhydroxyamide (PHA) comprising a fluorine group. More particularly, the synthesis method of PHA synthesizes PHA by sequentially passing through the steps of: dissolving diamine in a solution and cooling the solution using an ice bath; adding an amount of diacyl chloride equivalent to the amount of diamine to the cooled solution; mixing the solution containing added diacyl chloride at room temperature under nitrogen atmosphere for 30 minutes to 2 hours and conducting a reaction for 10 to 30 hours. The synthesis method of the present invention can condense a solution at low temperature and can lower cyclization temperature, thereby reducing energy required to synthesize polybenzoxazole (PBO) from PHA.

Description

[0001] The present invention relates to a method for producing polyhydroxyamides having fluoro groups,

The present invention relates to a process for preparing a polyhydroxyamide having a fluorine group introduced thereto, and more particularly, to a process for producing a polyhydroxyamide having a polyhydroxyamide, which is used as a precursor for producing polybenzoxazole by a low temperature solution condensation process, ≪ / RTI >

Polybenzoxazole (PBO) is a typical heterocyclic aromatic polymer that forms conjugated double bonds in a molecule, and has a linear rigid molecular structure. Therefore, the polybenzoxazole is not only excellent in mechanical properties, It exhibits the highest level of heat resistance, chemical resistance and flame retardancy. PBO fiber has been applied as aerospace materials, industrial reinforcing materials, and protective clothing materials that require high strength and high elasticity properties and are easy to operate at high temperature without pyrolysis. [J. F. Wolfe and F. E. Arnold, " igid-rod Polymers. 1. Synthesis and Thermal Properties of Para-aromatic Polymers with 2,6-benzobisoxazole Units in the Main Chain " Macromolecules, 1981, 14 (4), 909-915.

However, PBO is not melted due to its rigid structural properties, does not dissolve in organic solvents, and dissolves only in some strong acids, thus causing environmental problems and equipment corrosion problems. In addition, due to its high price, Which is used only in a part of the reality, and there are restrictions on the application to various applications. Various studies have been conducted to improve the solubility of PBO. Among them, Kantor et al. Proposed a polyhydroxyamide (PHA) which is superior in solubility and ease of handling than PBO as a precursor of PBO, A method of producing PBO has been reported. [C. Gao and S. W. Kantor, "" Synthesis of Precursor Flame Suppressing Polymers ", Spring SPE Meeting, 1996, 3072-3073.

PHA is an aromatic polyamide polymer obtained by reacting an aromatic diamine having two hydroxy groups on a benzene ring and an aromatic diacid chloride. It is well soluble in a polar organic solvent and has excellent moldability, excellent heat resistance and mechanical properties Fibers and films. In addition, PHA is very promising as a high performance fiber material itself, and it is expected that PBO fiber can be produced without using strong acid if it is converted into PBO at high temperature.

However, the above-mentioned PHA is also a forward-orientation polyamide-based polymer, which is converted to PBO only at a high temperature of 350 DEG C or more. To solve this problem, studies have been conducted to introduce a substituent into the side chain of PHA or introduce a flexible group or a bulky group into the main chain to improve the dissolution characteristics and to reduce the ringing temperature "Thermal Conversion of t-butyloxycarbonyloxy Attached Polyamides to Polybenzoxazoles", Polym Bulletin, 2000, 44, 55-62.) [TK Kim, KY Choi, KS Lee, DW Park and YJ Moon.

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1. [J. F. Wolfe and F. E. Arnold, " igid-rod Polymers. 1. Synthesis and Thermal Properties of Para-aromatic Polymers with 2,6-benzobisoxazole Units in the Main Chain " Macromolecules, 1981, 14 (4), 909-915. 2. [C. Gao and S. W. Kantor, "Synthesis of Precursor Flame Suppressing Polymers ", Spring SPE Meeting, 1996, 3072-3073. 3. [T. K. Kim, K. Y. Choi, K. S. Lee, D. W. Park, and Y. J. Moon, "Thermal Conversion of t-butyloxycarbonyloxy Attached Polyamides to Polybenzoxazoles", Polym Bulletin, 2000, 44, 55-62.

In order to solve the above problems, it is an object of the present invention to provide a method for producing a polyhydroxyamide (PHA) having a fluorine group introduced therein to easily produce polybenzoxazole (PBO) at a low temperature.

In order to solve the above problems,

Cooling the solution obtained by dissolving the diamine in a solvent using an ice bath; Adding the same equivalent amount of diacyl chloride as the diamine to the cooled solution; Stirring the solution containing the diacyl chloride in a nitrogen atmosphere at room temperature for 30 minutes to 2 hours, and then conducting the reaction for 10 to 30 hours; And a method for producing the polyhydroxyamide, which is characterized in that the polyhydroxyamide is produced in succession.

The diamine may be selected from the group consisting of 3,3'-dihydroxybenzidine (DHB) or 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane 3-amino-4 hydoxyphenyl) hexafluoropropane, BAHHFP)

The solvent is selected from N, N-dimethylacetamide, DMAc, 1-methyl-2-pyrrolidone (NMP), and the diacyl chloride Is characterized by being selected from isophthaloyl chloride (IPC) or terephthaloyl chloride (TPC).

Further, the polyhydroxyamide is characterized in that flourine is introduced at the ortho or para position,

The polyhydroxyamide has an intrinsic viscosity of 0.35 to 3.3 dl / g as measured using a Ubbelohode viscometer in a constant temperature water bath at 30 ± 0.1 ° C after dissolving in sulfuric acid at a concentration of 0.5 g / dl.

The polyhydroxyamide (PHA) with the fluorine produced by the present invention can lower the ringing temperature by allowing low-temperature solution condensation, thereby reducing the amount of energy required for producing polybenzoxazole (PBO) from PHA There is an effect that can be reduced.

1 is a diagram showing reaction formulas of p-PHA, m-PHA, pF-PHA and mF-PHA of the present invention.
Figure 2 shows FT-IR spectra of four different PHAs prepared according to the present invention.
3 is a graph showing the degree of cyclization of p-PHA with respect to the temperature and time of the heat treatment.
4 is a graph showing the degree of cyclization of m-PHA according to the temperature and time of the heat treatment.
5 is a graph showing the degree of cyclization of pF-PHA with the temperature and time of the heat treatment.
6 is a graph showing the degree of cyclization of mF-PHA according to the temperature and time of the heat treatment.
7 is a view showing FT-IR spectra of PBO prepared from p-PHA, m-PHA, pF-PHA and mF-PHA.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the following figures and examples.

In describing the present invention, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

The present invention relates to a method for preparing PBO by synthesizing p-PHA and m-PHA and fluorine-introduced pF-PHA and mF-PHA in the main chain using a low temperature solution condensation method and thermolyzing the polymer .

The structural formulas of p-PHA, m-PHA, pF-PHA and mF-PHA are as follows.

 p-PHA

 m-PHA

 pF-PHA

mF-PHA

The p-PHA, the m-PHA, the pF-PHA and the mF-PHA were synthesized by using 3,3'-dihydroxybenzidine (DHB) or 2,2-bis 3-amino-4-hydoxyphenyl) hexafluoropropane (BAHHFP) as a diamine, isophthaloyl chloride (IPC) or terephthalic acid With terephthaloyl chloride (TPC). The IPC and TPC are added to the diacyl chloride for producing the PHA of the present invention.

The PHA to which the fluorine group of the present invention is introduced includes a step of cooling a solution obtained by dissolving a diamine in a solvent using an ice bath; Adding the same amount of diacyl chloride as the diamine to the cooled solution, stirring the solution to which the diacyl chloride has been added at room temperature and under nitrogen atmosphere for 30 minutes to 2 hours, and then performing the reaction for 10 to 30 hours ; Are sequentially manufactured.

The diamine is selected from DHB or BAHHFP, the solvent is selected from DMAc, NMP, and the diacyl chloride is selected from IPC or TPC.

The PHA of the present invention prepared by the above-mentioned method has an intrinsic viscosity of 0.35 to 3.3 dl / g as measured using a Ubbelohode viscometer in a constant temperature water bath at 30 ± 0.1 ° C after dissolving in sulfuric acid at a concentration of 0.5 g / dl, When heat treated at 300 ~ 370 ℃ for 5 minutes, it is converted to PBO 100%.

Hereinafter, the present invention will be described in more detail by way of examples.

[Example 1: Synthesis of PHA]

A solution of 3,3'-dihydroxybenzidine (DHB, 99.0%, Tokyo Chemical Industry) dissolved in anhydrous grade N, N-dimethylacetamide (DMAc, 99.8%, Sigma Aldrich) as a solvent was dissolved in an ice bath (TPC, 99.0%, Tokyo Chemical Industry) was added in the same amount as that of DHB, stirred for 1 hour, reacted at room temperature in a nitrogen atmosphere for 24 hours, precipitated in distilled water, For 24 hours to synthesize PHA.

The FT-IR spectra of four different PHAs synthesized by different diamines, diacyl chlorides and solvents (see Table 1) under the same reaction conditions as those of the above examples are shown in FIG. 3412 cm ^-1, which commonly corresponds to the structure of the PHA in the respective spectrum ^{(NH stretching), 3500-3000 cm -1} (OH stretching), 1647 cm -1 (C = O stretching), 1604 cm -1 (CC vibration ), 1527 cm ^-1 (coupling of CN stretching and NH bending), and 1408 cm ^-1 (COH bending), and the pF-PHA and mFPHA spectra, 1300-1100 cm ^-1 (CF stretching) The corresponding characteristic band was observed. This confirmed that four different PHAs were synthesized.

On the other hand, the dried PHA was dissolved in sulfuric acid at a concentration of 0.5 g / dl, and the intrinsic viscosity was 2.23 dl / g as measured using a Ubbelohode viscometer in a constant temperature water bath at 30 ± 0.1 ° C.

The intrinsic viscosity values are shown in Table 1.

In Table 1, solvent NMP means 1-methyl-2-pyrrolidone.

Sample
identification Diamine Diacyl chloride solvent I.V. (dl / g) p-PHA DHB TPC DMAc  2.23 m-PHA DHB IPC DMAc 1.37 pF-PHA BAHHFP  TPC NMP 0.53 mF-PHA BAHHFP IPC NMP  0.47

[Example 2: Heat treatment of PHA]

The synthesized PHA was thermally treated at different temperatures and times in each sample in a laboratory scale heat treatment apparatus in which the temperature was precisely controlled. Based on the results of TGA and DSC, four kinds of PHA were selected from four temperature conditions in the range of 250 ~ 400 ℃ and heat treatment was performed for each time (5, 15, 30, 60 min) All experiments were carried out under a nitrogen stream. The results are shown in Figs. 3 to 6. PHA (FIG. 3) was converted to 100% PBO by heat treatment at 370 ° C. for 30 minutes and m-PHA (FIG. 4) was converted to 100% PBO by heat treatment at 330 ° C. for 30 minutes. PHA (FIG. 5) was converted to 100% PBO by heat treatment at 320 ° C. for 5 minutes, and mF-PHA (FIG. 6) was converted to 100% PBO by heat treatment at 300 ° C. for 5 minutes. It was shown that the incorporation of fluorine groups into the PHA backbone could accelerate the cyclization and reduce the energy consumption required for conversion from PHA to PBO.

FIG. 7 shows FT-IR spectral analysis results of the heat-treated samples of the synthesized p-PHA and m-PHA, pF-PHA and mFPHA under the conditions of the degree of cyclization of 100%. In all spectra, the characteristic bands of 1617 cm ^-1 (C = N stretching), 1459 cm ^-1 (C = N bending) and 1087 cm ^-1 (CO stretching) ^-1 (NH stretching) and 3500 ~ 3000 cm ^-1 (OH stretching), the PBO was completely synthesized.

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Claims (4)

In the process for producing a polyhydroxyamide,
The method comprises: cooling a solution of a diamine in a solvent using an ice bath;
Adding the same equivalent amount of diacyl chloride as the diamine to the cooled solution;
Stirring the solution containing the diacyl chloride in a nitrogen atmosphere at room temperature for 30 minutes to 2 hours, and then conducting the reaction for 10 to 30 hours; Characterized in that the polyhydroxyamide is produced by the sequential process
The method according to claim 1,
The diamine may be selected from the group consisting of 3,3'-dihydroxybenzidine (DHB) or 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane 3-amino-4-hydoxyphenyl) hexafluoropropane, BAHHFP)
The solvent is selected from N, N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP)
Characterized in that the diacyl chloride is selected from isophthaloyl chloride (IPC) or terephthaloyl chloride (TPC).
3. The method of claim 2,
Characterized in that the polyhydroxyamide has fluorine introduced at the ortho or para position
4. The method according to any one of claims 1 to 3,
Wherein the polyhydroxyamide has an intrinsic viscosity of 0.35 to 3.3 dl / g as measured using a Ubbelohode viscometer in a constant temperature water bath of 30 占 0.1 占 폚 after dissolving in sulfuric acid at a concentration of 0.5 g / dl. Amide

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