KR101652699B1 - Polyhydroxyamides substituted flruoro-substituents and method for preparing of the same - Google Patents

Abstract

The present invention provides polyhydroxyamides substituted with fluorine substituents and a process for their preparation.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a polyhydroxyamide substituted with a fluorine-based substituent and a process for producing the same. BACKGROUND ART < RTI ID = 0.0 > POLYHYDROXYAMIDES SUBSTITUTED FLUORO-SUBSTITUENTS AND METHOD FOR PREPARATION OF THE SAME &

The present invention relates to polyhydroxy amides substituted with fluorine substituents and a process for their preparation.

The most effective way to prevent burning of organic materials such as fibers and films is to design heat-resistant polymers that can withstand heat, resist flame propagation, and maximize combustion speed.

In general, well-known heat-resistant polymers include polybenzoxazole (PBO), polyimide (PI), and polybenzothiazole (PBZT), which are thermally stable and rigid benzene rings or hetero rings in the main chain. So that it has a merit of being able to suppress the formation of high carbide and generation of flammable gas as much as possible.

Heterocyclic aromatic polymers such as PBO can be obtained through a two - step process: polymerization to obtain high polymerization degree and cyclization by thermal or chemical reaction. However, due to the rigid molecular structure of the heterocyclic aromatic polymer, the final polymer does not dissolve in the organic solvent but dissolves only in some strong acids. Therefore, it requires not only a separate technical skill in molding and processing but also a limitation in application to various products It is also true. In order to solve these technical problems, Kantor et al. Proposed a poly (3,3'-dihydroxybiphenyl isophthalamide) (PHA) which can be used as a precursor of PBO. The synthesized PHA is N, N-dimethylacetamide (DMAc), N-methylpyrrolidone NMP) and N, N-dimethylformamide (DMF), it is advantageous to be converted into PBO by the cyclization reaction without ultimately being restricted in molding and processing.

Various studies have been made on precursors capable of being converted into PBO by ringing, such as PHA, which can be dissolved in an organic solvent. In order to improve the solubility of PHA or to synthesize PBO precursors similar to PHA, The possibility of PHA in various fields such as spinning, nano-web fabrication using electrospinning, nanocomposites, membranes, and microelectronic devices has been continuously examined.

On the other hand, since PHA can be converted into PBO, it has heat resistance similar to that of PBO, but it emits fire extinguishing substances such as water when PBO is converted, so it has better advantages than PBO in terms of heat resistance and flame retardancy. Generally, the cyclization of PHA is initiated by nucleophilic attack of hydroxyl group with carbonyl group at ortho position of benzene ring with NH of amide group, and this cyclization reaction is known to occur at a high temperature of 300 ° C or more. Therefore, lowering the cyclization temperature of PHA is considered to be very important in terms of rapid release of digestive material and PBO conversion. In addition, molecular designing for the digestion material released from the cyclization reaction to exhibit better flame retardancy It can be considered important. From this point of view, Baik et al. Evaluated the cyclization rate of PHA model compounds according to the type of alkyl ester substituent, and confirmed that the longer the substituent length and the larger the volume, the faster the cyclization rate. In addition, it was confirmed that a halogen substituent was applied to the PHA model compound and the cyclization reaction at a lower temperature than that of the existing PHA was possible so as to exhibit an excellent flame retardant effect as a digesting material released in the cyclization reaction.

The present invention provides a polyhydroxyamide having a fluorine substituent introduced into polyhydroxyamides (PHA) synthesized by low-temperature solution condensation polymerization and a method for producing the same.

The present invention provides a polyhydroxyamide substituted with a fluorine-based substituent represented by the following formula (1).

In Formula 1,

R is selected from the group consisting of (CF ₂ ) _x CF ₃ , CF {(CF ₂ ) _y CF ₃ } ₂ and C {(CF ₂ ) _z CF ₃ } ₃ ,

x is an integer of 0 to 9, y is an integer of 0 to 6, z is an integer of 0 to 3,

and n is an integer of 50 to 1,000.

The polyhydroxyamide substituted with the fluorine substituent is characterized by being capable of being converted into a polybenzoxazole by a cyclization reaction.

The present invention also provides a method for producing the compound of claim 1 by reacting a compound represented by the following formula (2) with a compound represented by the following formula (3).

In Formula 2,

and n is an integer of 50 to 1,000.

In Formula 3,

R is selected from the group consisting of (CF ₂ ) _x CF ₃ , CF {(CF ₂ ) _y CF ₃ } ₂ and C {(CF ₂ ) _z CF ₃ } ₃ ,

x is an integer of 0 to 9, y is an integer of 0 to 6, and z is an integer of 0 to 3.

The fluorinated substituent-substituted polyhydroxyamides according to the present invention are excellent in solubility in an organic solvent and can be rapidly converted into a polybenzoxazole structure because of low activation energy required for a cyclization reaction. Further, it can be used as a fiber polymer material exhibiting better heat resistance and flame resistance properties as fluorine substituent is released.

Brief Description of the Drawings Fig. 1 is a graph showing results of FT-IR spectroscopic analysis of PHA (PHA-1) and PHA derivatives (PHA-2 and PHA-3)
Figure 2 shows DSC (differential scanning calorimetry) heating curves of PHA and PHA derivatives according to the examples.
3 is a graph showing isothermal cyclization of PHA and PHA derivatives according to the examples.
4 is a graph showing the rates for isothermal cyclization of PHA and PHA derivatives according to the examples.
FIG. 5 is a graph showing the results of TGA (thermogravimetric analysis) analysis of PHA and PHA derivatives according to Examples.

Hereinafter, the present invention will be described in detail.

The present invention provides a polyhydroxyamide of the above formula (1) wherein the fluorine substituent is substituted.

The polyhydroxyamide substituted with a fluorine-based substituent represented by the general formula (1) has structural specificity in which the hydroxy group of the polyhydroxyamide side chain is substituted with a fluorine-based substituent.

The method for preparing the fluorinated substituent-substituted polyhydroxyamide represented by the above formula (1) according to the present invention is not particularly limited, but it can be produced through the process as shown in the following reaction formula (1).

[Reaction Scheme 1]

In the above Reaction Scheme 1,

R is selected from the group consisting of (CF ₂ ) _x CF ₃ , CF {(CF ₂ ) _y CF ₃ } ₂ and C {(CF ₂ ) _z CF ₃ } ₃ ,

x is an integer of 0 to 9, y is an integer of 0 to 6, z is an integer of 0 to 3,

and n is an integer of 50 to 1,000.

As shown in Reaction Scheme 1, the fluorinated substituent-substituted polyhydroxyamide according to the present invention can be prepared by reacting the compound represented by Formula 2 and the compound represented by Formula 3. Specifically, the compound represented by Formula 2 is a pure polyhydroxyamide, and the compound represented by Formula 3 is a fluorine-based substituent having a linear structure and a fluorine-based substituent having a branched structure.

The compound represented by Formula 2 is dissolved in an organic solvent (for example, dimethylformamide) and then stirred at room temperature with the compound represented by Formula 3 to conduct the reaction. After completion of the reaction, water And vacuum dried to prepare a polyhydroxyamide substituted with the fluorine-based substituent of the present invention.

In the above Reaction Scheme 1, the reaction molar ratio of the hydroxy group of the pure polyhydroxyamide (Formula 2) to the fluorine-based substituent of the linear structure or the fluorine substituent of the branched structure (Formula 3) is not particularly limited, 1: 5 molar ratio, preferably 1: 1. The amount of the organic solvent to be used is not particularly limited, but can be appropriately adjusted within a usual range.

The compound of formula (2) is not particularly limited and may be prepared by the following reaction scheme (2).

[Reaction Scheme 2]

In the above Reaction Scheme 2, n is an integer of 50 to 1,000.

As shown in Scheme 2, the pure polyhydroxyamide according to the present invention may be prepared by reacting 3,3'-dihydroxybenzidine (DHB) with terephthaloyl chloride (TPC) or Can be prepared by dissolving isophthaloyl chloride (IPC) in an organic solvent (for example, dimethylacetamide), followed by condensation polymerization at a low temperature under a nitrogen stream.

Hereinafter, the present invention will be described in detail with reference to examples. However, these examples are for illustrating the present invention specifically, and the scope of the present invention is not limited to these examples.

<Material>

PHA was polymerized using 3,3'-dihydroxybenzidine (DHB, 99.0%, Tokyo Chemical industry) and isophthaloyl chloride (IPC, 99.0%, Sigma-Aldrich) as monomers. The solvent was anhydrous DMAc (99.8%, Sigma-Aldrich ) Was used.

4-pyrrolidinopyridine (98.0%), trifluoroacetic anhydride (99.0%) and heptafluorobutyric anhydride (99.0%) were purchased from Sigma-Aldrich for the synthesis of PHA derivatives with fluorine substituents. All reagents and solvents were added Without purification.

(99.5%, Samchun Chemical), NMP (99.5%, Daejung Chemical & Metals), dimethyl sulfoxide (DMSO, 99.0%, Samchun Chemical), and tetrahydrofuran (DMSO) to confirm the solubility of the synthesized PHA and PHA derivatives. THF, 99.5%, Samchun Chemical) was purchased and used.

&Lt; Comparative Example 1 > Preparation of PHA-1

DHB and IPC, which are monomers, were dissolved in DMAc as a solvent, and PHA-1 was prepared by condensation polymerization at a low temperature under a nitrogen stream.

Example 2 Synthesis of PHA-2 Derivative

PHA-1 (0.693 g, 0.0048 mol) prepared in Comparative Example 1 and 4-pyrrolidinopyridine (0.685 g, 0.0048 mol) were dissolved in DMF (11 ml) added with LiCl (2.0 wt%) and trifluoroacetic anhydride g, 0.0048 mol) at room temperature for 3 hours. After the reaction was completed, the reaction mixture was precipitated in water and vacuum-dried for 24 hours.

Example 3 Synthesis of PHA-3 Derivative

A PHA-3 derivative was synthesized in the same manner as in Example 2 except that heptafluorobutyric anhydride (1.9683 g, 0.0048 mol) was used in place of trifluoroacetic anhydride.

Experimental Example 1 Evaluation of Substitution of PHA-1 and PHA Derivatives (PHA-2 and PHA-3)

In order to evaluate the degree of substitution of the PHA-1 and PHA derivatives (PHA-2 and PHA-3) synthesized in Examples and Comparative Examples, a thermogravimetric analyzer (TGA Q50, TA Instruments) The actual weight loss rate was measured and evaluated.

As a result of the analysis, the pure water PHA (PHA-1) prepared in the preparation example showed a real weight reduction rate very close to the theoretical weight reduction rate of 10.4%, and the fluorine-substituted PHA-2 (Example 1) and PHA- (Example 2) showed a substitution ratio of 54.3% and 42.6%, respectively. Thus, it was confirmed that the PHA derivative prepared in the Example was not 100% substituted, but was in the PHA derivative having a substitution ratio of about 40-50%.

<Experimental Example 2> FT-IR spectrum analysis of PHA-1 and PHA derivatives (PHA-2 and PHA-3)

FT-IR spectrum analysis of PHA-1 and PHA derivatives (PHA-2 and PHA-3) synthesized in Examples and Comparative Examples was performed using a Perkin-Elmer analyzer (Magna IR550) .

As can be seen in Figure 1, the spectrum of PHA-1, PHA-2 and PHA-3 is 3412cm ^-1 (NH stretching), which commonly corresponds to the structure of ^{PHA, 3000 ~ 3400cm -1 (OH} stretching), 1647cm ^-1 (C = O stretching), 1604 cm ^-1 (CC vibration), and 1527 cm ^-1 (coupling of CN stretching and NH bending).

Since the PHA derivatives (PHA-2 and PHA-3) are not 100% substituted, the characteristic band due to COH bending (1408 cm ^-1 ) still exists, but the intensity thereof is relatively reduced. On the other hand, it was confirmed that a new characteristic band appeared at 1735 cm ^-1 , 1228 cm ^-1 , and 1162 cm ^-1 , and it was confirmed that the substitution of -COC ester, CF ₃ (CF stretching) and CF ₂ ). As a result, the synthesis of PHA and the conversion of PHA derivative were found to be well performed through FT-IR structure analysis as a whole.

<Experimental Example 3> Evaluation of solubility of PHA-1, PHA derivatives (PHA-2 and PHA-3)

PHA-1, PHA-2 and PHA-3 were dissolved in DMAc, DMF, DMSO and NMP to evaluate the solubility of the PHA-1 and PHA derivatives (PHA-2 and PHA-3) synthesized in Examples and Comparative Examples The solubility in organic solvents was evaluated. Each sample (PHA-1, PHA-2, PHA-3) was added to the prepared solvent and visually observed at room temperature. Solubility results are shown in Table 1 below.

As can be seen from Table 1, PHA-1 having only a hydroxyl group in its side chain was dissolved in organic solvents such as DMAc, DMF, DMSO, and NMP only in the state where LiCl was added. On the other hand, PHA- (PHA-2 and PHA-3) can be dissolved in organic solvents such as DMAc, NMP and DMSO, except for most of the LiCl except for DMF. The difference in solubility between PHA-1 and PHA derivatives (PHA-2 and PHA-3) is due to the reduction of the packing efficiency of molecular sars caused by substituents in the side chain, And the increase of the fluidity of the chain. As a result, it seems to have a great advantage in molding and processing than general PHA.

Solubility Organic solvent DMAc DMF DMSO NMP PHA-1 ○ ○ ○ ○ PHA-2 Xx ○ Xx Xx PHA-3 Xx ○ Xx Xx

○ ○: soluble without LiCl, ○: soluble with LiCl

<Experimental Example 4> Analysis of the cyclization behavior of PHA-1, PHA derivatives (PHA-2 and PHA-3)

In order to analyze the cyclization behavior of the PHA-1 and PHA derivatives (PHA-2 and PHA-3) synthesized in Examples and Comparative Examples, a differential scanning calorimeter (DSC 2910, TA Instruments) / min and the endothermic peak according to the cyclization reaction was compared and analyzed.

Fig. 2 shows DSC heating curves of PHA-1 and PHA derivatives (PHA-2 and PHA-3). As can be seen from FIG. 2, in the case of PHA-1 without substitution, the cyclization initiation started at about 260 ° C, and the cyclization reaction was terminated at 396 ° C. On the other hand, in the case of PHA-2 and PHA-3 with fluorine substituents introduced, it can be seen that the cyclization initiation and termination temperatures are lower than PHA-1, and the temperature ranges from 247 to 373 캜 and from 222 to 352 캜 . That is, when a substituent is introduced instead of a hydroxy group, the cyclization initiation is accelerated, and the longer the substituent length is, the faster the cyclization initiation becomes.

(PHA-1, PHA-2, and PHA-3) sealed in ampoules were treated with a salt bath (NaNO ₂ 40%, NaNO ₃ 7% KNO ₃ 53%), and heat treatment was performed at 220 ° C. and 250 ° C. for a maximum of 160 minutes, respectively. The results are shown in FIG.

3, the degree of cyclization at 220 ° C and 150 min was 0.25 for pure PHA-1 without substitution, while the degrees of cyclization of PHA-2 and PHA-3 were 0.8 and 0.9, respectively . In the DSC analysis, PHA-3, which exhibited the fastest cyclization start temperature, showed a degree of cyclization close to 1 in an isothermal state at 250 ° C for 30 minutes. In the case of PHA-2, the degree of cyclization was 1 And showed close values. On the other hand, the degree of cyclization of PHA-1 was 250 ° C and 0.45 degree at 150 minutes.

The rate of isothermal cyclization at each temperature was evaluated by the first-order rate equation of the following equation based on the results of FIG. 3, and the results are shown in FIG. 4 and Table 2 below.

Wherein, [A] _o is the cyclization reaction is the concentration of the non-progress PHA samples [A] _t is the cyclization reaction after passing the time t indicates the concentration of the PHA sample that is in progress, α and k are each ring And the rate constant and rate constant.

As can be seen from FIG. 4 and Table 2, it can be seen that the rate constant increases from PHA-1 to PHA-2 and PHA-3, and the isothermal cyclization evaluation shows that the hydroxy group of pure PHA is fluorine- It can be interpreted that the cyclization proceeds more rapidly at low temperature when the substituent is substituted. Therefore, it is possible to design a fiber polymer material capable of manifesting excellent heat resistance and flame retardancy due to rapid release of a fluorinated digesting material at a low temperature, together with an advantage of being able to dissolve in various organic solvents by introducing a fluorine-based substituent into PHA .

Rate constant (min ^-1 ) Activation energy (kJ / mol) 220 ℃ 250 ℃ PHA-1 2.07x10 ^-3 3.67x10 ^-3 196.4 PHA-2 1.29x10 ^-2 1.45x10 ^-2 70.3 PHA-3 2.40x10 ^-2 9.44x10 ^-2 49.4

Experimental Example 5 Evaluation of activation energy and thermal stability of PHA-1, PHA derivatives (PHA-2, PHA-3)

A thermogravimetric analyzer (TGA Q50, TA Instruments) was used to evaluate the thermal stability of PHA-1 and PHA derivatives (PHA-2 and PHA-3) synthesized in Examples and Comparative Examples. The measurement was carried out at 20 ° C / min from room temperature to 900 ° C, and the results are shown in FIG.

In general, the thermal properties of PHA represent a primary weight loss by cyclization and a secondary weight loss by pyrolysis of PBO converted by cyclization. At this time, the primary weight reduction of PHA is very important because it can relatively evaluate the degree of cyclization and the substitution rate of substituents, and also provides the cyclization temperature range, activation energy required for cyclization, and the like.

FIG. 5 shows the results of TGA analysis of PHA-1 and PHA derivatives (PHA-2 and PHA-3), showing a primary weight reduction by cyclization over a temperature range of 200 to 400 ° C., The secondary weight reduction by pyrolysis of PBO was observed before and after. The initial weight reduction initiation temperatures of PHA-1 and PHA derivatives (PHA-2 and PHA-3) in the TGA phase also decreased in the order of PHA-1, PHA-2 and PHA-3, The results are also consistent with the results of the behavior analysis.

Further, based on the cyclization behavior occurring in the temperature range of the primary weight reduction, the activation of the PHA-1 prepared in Preparation Example and the PHA derivative (PHA-2 and PHA-3) synthesized in Example 1 and Example 2 Energy (activation energy, E _a ) was evaluated and a relative comparison was made for the cyclization reaction.

The activation energy E _a for the cyclization behavior of PHA-1 and PHA derivatives (PHA-2 and PHA-3) was calculated by varying the heating rate of TGA at 2, 7, 10, 15, Respectively.

In the above equation, T _p , R and C denote the cyclization temperature, the gas constant, and the heating rate of TGA, respectively.

The activation energies for the cyclization behavior of PHA-1 and PHA derivatives (PHA-2 and PHA-3) obtained from the TGA analysis and the above formulas are shown in Table 2 above. PHA-1 is 193.4 kJ / mol, PHA- Was 70.3 kJ / mol, and that of PHA-3 was 49.4 kJ / mol. That is, the activation energy analysis results show that the cyclization reaction of the PHA (PHA-2, PHA-3) derivatives substituted with the fluorine substituent is relatively easier than the pure PHA (PHA-1), and the longer the substituent is, And the results are consistent with the results of the rate constant analysis by the isothermal cyclization.

On the other hand, PHA-1 and PHA derivatives (PHA-2 and PHA-3) in which cyclization has been completed should not theoretically lose weight until the secondary weight reduction corresponding to the decomposition of PBO. However, in the TGA graph of FIG. 5, the weight reduction of PHA-1, which is a pure PHA-1, is small until the final decomposition after the cyclization, whereas the PHA derivatives (PHA-2 and PHA-3) It shows what happens. This phenomenon can be assumed to be that the relatively bulky fluorine substituent leaving the main chain after the cyclization reaction remains within the PBO matrix and is slowly released with increasing temperature.

Claims (3)

1. A polyhydroxyamide substituted with a fluorine-based substituent represented by the following formula (1).
[Chemical Formula 1]

In Formula 1,
R is selected from the group consisting of (CF ₂ ) _x CF ₃ , CF {(CF ₂ ) _y CF ₃ } ₂ and C {(CF ₂ ) _z CF ₃ } ₃ ,
x is an integer of 0 to 9, y is an integer of 0 to 6, z is an integer of 0 to 3,
and n is an integer of 50 to 1,000. The method according to claim 1,
The polyhydroxyamide substituted with the fluorine-based substituent is a polyhydroxyamide substituted with a fluorine-based substituent convertible to polybenzoxazole by a cyclization reaction. A process for producing a compound of claim 1 by reacting a compound represented by the following formula (2) with a compound represented by the following formula (3).
(2)

In Formula 2, n is an integer of 50 to 1,000.
(3)

In Formula 3,
R is selected from the group consisting of (CF ₂ ) _x CF ₃ , CF {(CF ₂ ) _y CF ₃ } ₂ and C {(CF ₂ ) _z CF ₃ } ₃ ,
x is an integer of 0 to 9, y is an integer of 0 to 6, and z is an integer of 0 to 3.

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