KR920009684B1 - Polyazomethin resin and process for preparing thereof - Google Patents

Abstract

A processable polyazometin resin of formula (I) is new. (I) is prepd. by solution polymerising 2,5-dialkoxy terephthal aldehyde of formula (II) with equivalent mole of 1,4-phenylene diamine or benzidine in a mixed solvent comprising 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone and N-methyl- 2pyrrolidone, at 80 deg.C for 24 hrs. (I) has 0.13-0.17 dl/g of inherent viscosity and 4.8 x 10-6 - 1.1 x 10-2 s/cm of electro-conductivity. In the formulas, X is phenyl or biphenyl; R is C8-18 alkyl; p is 3-30.

Description

Processable polyazomethine resin and its manufacturing method

1 is an IR spectrum of the polyazomethine resin according to the present invention.

2 is a ¹ H-NMR spectrum of the polyazomethine resin according to the present invention

3 is a DSC curve of the polyazomethine resin according to the present invention.

4 is an X-ray diffraction curve of the polyazomethine resin according to the present invention.

The present invention relates to a processable polyazomethine resin and a method for producing the same, and more particularly, to a polyazomethine resin represented by the following general formula (I) and a method for producing the same.

Wherein X is a phenyl group or a biphenyl group, and R is one of alkyl groups having 8 to 18 carbon atoms. In addition, P represents the integer of 3-30.

Conductive organic polymer materials are of great interest in the industry due to their unusual electrical and optical properties.

However, most conductive polymers do not dissolve well in organic solvents and are difficult to melt at high temperatures, which is a major problem in processability.

In recent years, there have been reports of lowering strategies to improve processability by substituting flexible side chains in the backbone of conductive polymers (J. Chem. Soc., Chem. Comm. 1987.873; Synth.Met. 18.229 (1987)). Polymers are not only readily soluble in common organic solvents, but can also be melted by heating, and are known to exhibit high electrical conductivity in films or melt-molded films obtained from casting services.

On the other hand, research has been reported to produce a high molecular weight polyazomethine through the production of Schiff salts such as diamine and dialdehyde (Macomolecules 20.740 (1987)). In particular, the wholly aromatic polyazomethine is capable of high strength fibrosis (Macromolecules 20.729 (1989)). It has also been found that doping them with iodine shows quite high electrical conductivity (Polymer (Korea) 12,355 (1988)).

However, the polyazomethine polymer is also pointed out as a problem that, like other conductive polymers, poor processability.

Accordingly, the present invention provides a novel polyazomethine resin which can be dissolved and melted well in various organic solvents while maintaining the conductivity thereof in order to alleviate the drawbacks of the true aromatic polyazomethine. There is a purpose.

Hereinafter, the present invention will be described in detail.

The present invention is a workable polyazomethine resin represented by the following general formula (I).

Wherein X is a phenyl group or a biphenyl group, and R is one of an alkyl group having 8 to 18 carbon atoms. In addition, P represents the integer of 3-30.

The polyazomethine resin of the general formula (I) according to the present invention is reacted with 2.5-dialkoxy terephthal aldehyde represented by the following general formula (II) with an equimolar amount of 1,4-phenylenediamine or benzidine. It can be prepared by reacting by two methods, namely, solution polymerization method or melt polymerization method.

In the formula, R represents a phenyl group substituted with an alkyl group having 8 to 18 carbon atoms.

Hereinafter, the present invention will be described in more detail.

The polyazomethine resin of the general formula (I) according to the present invention may be prepared according to the following two methods.

[Solution Polymerization Method]

Mixture of 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyridiminone (hereinafter referred to as DMPN) and N-methyl-2-pyrrolidone (hereinafter referred to as NMP) Under a solvent, 2,5-dialkoxyterephthalaldehyde represented by the general formula (II) and an equimolar amount of 1,4-phenylenediamine or benzidine are reacted at a temperature of 80 ° C. for 24 hours.

[Melt polymerization method]

Under a nitrogen atmosphere, 2,5-dialkoxyterephthalaldehyde represented by the general formula (II) and an equimolar amount of 1,4-phenylenediamine or benzidine are reacted at a temperature of 200 ° C. for 2-3 hours. .

On the other hand, 2,5- dialkoxy terephthalaldehyde represented by the general formula (II) is prepared from 2,5- dialkoxy derephthaloyl chloride, tetrakis (triphenylphosphine) palladium (tetrakis (triphenylphosphine) palladium) as a catalyst and tributyltin hydride as an oxidant.

Although many methods for reducing aldehydes from carboxylic acids are known (Synthesis 1976, 767), this type of reaction has the advantage of obtaining aldehydes relatively quickly under mild conditions.

Here, 2, 5- dialkoxy terephthaloyl chloride can be obtained by applying the conventional method (Makromol. Chem. Rapid. Comm. 7,407 (1986)).

Among the polyazomethine resins of the general formula (I) prepared according to the present invention, the solution polymer obtained by the solution polymerization method was yellow to pale brown and changed to dark brown when heat treated or irradiated with light, and obtained by melt polymerization. The molten polymer was always obtained in dark brown color.

In the present invention, the production of the polymer was confirmed by infrared spectrophotometer (IR) and atomic magnetic resonance (NMR).

The 2-1 degree 1620cm ^-1 by a relatively strong C = N stretching vibration absorption band In the IR spectrum, COC stretching vibration 1200cm ^-1 when the alkoxy group.

In addition, in FIG. 2, the signal attributable to the hydrogen atom of the sipe salt is shown at 8.9 ppm of ¹ H-NMR, the aliphatic hydrogen of the alkoxy side chain is 0.8-2 ppm, and the phenyl group hydrogen is 7.2-7.8 ppm, respectively. can confirm.

The polyazomethine resin represented by the general formula (I) according to the present invention showed good solubility in chloroform even at room temperature, and was dissolved in carbon tetrachloride, tetrahydrobutane, benzene, toluene, etc. by heating.

These test results show that the flexible side chain is added to the backbone of the hard polymer, considering that the conventional wholly aromatic polyamethine resin obtained by the reaction of terephthalaldehyde with 1,4-phenylenediamine or benzidine is insoluble in general organic solvents. This indicates that the solubility of the polyazomethine resin can be significantly improved by introducing.

In addition, the thermal properties of the polyazomethine resins according to the present invention were investigated by differential scanning calorimetry (DSC), and showed extremely complex behavior depending on the polymerization method and molecular weight or heat treatment conditions.

That is, the wholly aromatic polyazomethine which binds to the para position without side chain is not melted even at 400 ° C. For example, the polyazomethine having a tetradecyloxy substituent or a hexadecyloxy substituent can be seen in FIG. As shown, melting points were observed around 260 ° C and 270 ° C, respectively.

In addition, as a result of investigating the thermal stability of the polymer by the thermal gravimetric analysis (TGA) method, it was confirmed that the weight loss of 5% showed good thermal stability as occurred at 365 ℃ -390 ℃ (see Table 2).

Figure 4 shows the X-ray diffraction curve at room temperature of the polyazomethine resin according to the present invention. Here, it can be seen that the crystallinity of the polymer is very high due to the appearance of a very clear reflex.

Sharp reflections, especially at the lowest angles, suggest that the polymer crystallizes in a layered structure, such as aromatic polyesters or polyimides (GP 3701249.5) with flexible side chains.

In addition, the polyazomethine resin of the semi-invention was formed into a pellet or film and doped with iodine, and then the electrical conductivity was measured by a four-probemethod. The polymer without side chain as -4 <δ <10-6 showed a lower value than δ = 10-2, and especially decreased as the side chain length increased. This phenomenon is believed to be due to the increase in the length of the alkoxy side chain, thereby increasing the distance between the polymer backbones, making it difficult to transfer electrons between the chains.

As mentioned above, the present invention solves the poorly soluble and high melting point problems of the conventionally aromatic polyazomethine in the production of polyazomethine resins, thereby significantly improving the molding processability, thereby requiring high strength and high modulus of elasticity. It is a great value that can be widely used as an advanced material in the industrial field.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1

[Synthesis of 2,5-dialkoxy terephthalaldehyde]

23.28 g (0.08 mole) of a mixture of 0.04 mole 2,5-dialkoxy terephthaloyl chloride and 0.46 g (0.4 × 10 ⁻³ mole) of Tetrikis (triphenylphosphine) palladium dissolved in 20 ml of benzene Tributyltin hydride is injected over 10 minutes.

The mixture is stirred under a nitrogen atmosphere at a temperature of 80 ° C. until reddish brown disappears, the solvent is distilled off, 100 ml of heptane is poured into the residue, and the precipitated palladium compound is filtered off.

Subsequently, the obtained mixed solution is cooled to room temperature and the resulting yellow precipitate is filtered and recrystallized from heptane.

The yield, melting point, and elemental analysis results of the aldehyde alkoxy group length are collected in Table 1.

IR (KBr pellet): 2850/2800 (ν (CH)), 1700 (ν (C = O)), 1500/1465 (δ (CH)), 1210 (ν (COC)), 720cm ^-1 (ν ( CH)).

¹ H-NMR (CDCl ₃ ): δ = 10.8 (S; CHO), 7.0-7.6 (m; 2H, aromatic), 3.8-4.2 (t; -OCH ₂ (CH ₂ ) _n CH ₃ ) 1.0-2.5 ( m; -OCH ₂ (CH ₂ ) _n CH ₃ ), 0.75-0.9 ppm (d; -OCH ₂ (CH ₂ ) _n CH ₃ )

TABLE 1

Example 2

[Solution Polymerization Method]

0.01 mole diamine, 0.02 g (0.1 × 10 ^-3 moles) bis (4-aminophenyl) ether and 0.1 g (6.1 × 10 ^-4 moles) in 10 ml DMPU containing 20 g of lithium chloride and 20 ml of NMP solution 4-acetamidobenzaldehyde was dissolved.

2, 5- dialkoxy terephthal aldehyde was added to this solution, and it stirred at 80 degreeC for 24 hours. Water was poured into it, the product was filtered off, washed with acetone and dried. In order to increase the purity of the polymer, it was dissolved in chloroform and poured slowly into heptane to catch the precipitate, followed by filtration and drying under reduced pressure of 60 ° C. to obtain a polymer.

Example 3

[Melt polymerization method]

0.01 mole diamine and 0.01 mole dialdehyde were stirred at 200 ° C. for 2.8 hours under nitrogen atmosphere. The portion produced during the reaction was removed by the passage of dry nitrogen gas.

After the reaction was completed, the polymer was cooled to room temperature, washed well, washed with acetone, and dried under vacuum at 60 ° C.

The properties of the polymers obtained by the two methods are listed in Table 2.

TABLE 2

A) Polymerization method A is solution polymerization and B is melt polymerization.

B) Intrinsic viscosity (ηinh) is measured in 30 ℃ chloroform solution.

C) MW is measured by GPC using polystyrene as reference material.

D) Weight loss was observed by TGA under nitrogen atmosphere at 10 ° C per minute.

E) Conductivity is measured by 4-point method by pelleting I ₂ -doped PAM.

** Electrical Conductivity of PAM Without Substituents (Polymer 12,355 (1988))

* L conductivity of molten film: 1.7 × 10 ^-4 S / cm

Claims (5)

Processable polyazomethine resin represented by the following general formula (I).

In the above formula, X is a phenyl group or a biphenyl group, R is an alkyl group having 8 to 18 carbon atoms, and P is an integer of 3 to 30. The polyazomethine resin according to claim 1, wherein the polyazomethine resin has an intrinsic viscosity (? Inh) of 0.13 to 0.17 dl / g and an electrical conductivity of 4.8 × 10 ⁻⁶ to 1.1 × 10 ⁻² S / cm. 2,5 represented by the following general formula (II) under a mixed solvent of 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone and N-methyl-2-pyrrolidone -A dialkoxy terephthal aldehyde and an equimolar amount of 1,4-phenylene diamine or benzidan are solution polymerized, and the reaction is carried out at a temperature of 80 ° C. for 24 hours, which is represented by the following structural formula (I): Manufacturing method of polyazomethine resin

In the above formula, X is a phenyl group or a biphenyl group, R is an alkyl group having 8 to 18 carbon atoms, and P is an integer of 3 to 30. The 2,5-dialkoxy phthalphthalaldehyde represented by General Formula (II) is characterized by using tetrakis (triphenylphosphine) palladium as a catalyst and tributyltinhydride as an oxidizing agent. , 5-dialkoxy terephthaloyl chloride. Under a nitrogen atmosphere, 2,5-dialkoxy terephthalaldehyde represented by the following general formula (II) and an equivalent molar amount of 1,4phenylene diamine or benzidine are melt-polymerized, and the mixture is heated at a temperature of 200 ° C. for 2-3 hours. A method for producing a polyazomethine resin represented by the following general formula (I), characterized in that the reaction.

In the above formula, X is a phenyl group or a biphenyl group, R is an alkyl group having 8 to 18 carbon atoms, and P is an integer of 3 to 30.

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