KR102425311B1 - Polymer composite materials containing aramid nanofiber and method for preparing the same - Google Patents

Abstract

The present invention relates to a polymer composite material comprising aramid nanofibers (ANF) and a method for manufacturing the same. More specifically, an arylene ether-based polymer or an arylene ether-imide-based polymer is mixed with a polar aprotic solution in which aramid nanofibers are dispersed, or an arylene ether polymerized by adding a monomer to a solution in which the aramid nanofibers are dispersed. It relates to a polymer-based polymer or an arylene ether imide-based polymer composite material.

Description

Polymer composite material containing aramid nanofibers and manufacturing method thereof

The present invention relates to a polymer composite material comprising aramid nanofibers (ANF) and a method for manufacturing the same. More specifically, it relates to an arylene ether-based polymer composite material or an arylene ether imide-based polymer composite material including aramid nanofibers, and a manufacturing method thereof.

Arylene ether-based polymers or arylene ether imide-based polymers are known to have excellent flame retardancy, heat resistance and chemical resistance, and are applied to electronic device sockets, engine parts, aviation materials, military materials, and membranes.

In order for these arylene ether-based polymers or arylene ether imide-based polymers to be applied to high-tech industrial plastics, they must be light, high heat-resistant, and have high mechanical strength. It is manufactured as a composite material together with nano fillers such as carbon fiber.

However, when manufacturing an arylene ether-based polymer or an arylene ether-imide-based polymer composite material using glass fibers or carbon fibers, in order to provide sufficient mechanical strength, glass fibers or carbon fibers must be used in an amount greater than necessary. Although strength can be improved, workability, surface smoothness, etc. appear as problems.

In addition, when mixing aramid bulk fibers prepared by spinning a dopant with a sulfuric acid solution with a polymer, there is a problem in that it is difficult to obtain the expected improvement in physical properties, and research to solve this problem is continuously being conducted.

Moreover, when the conventional fibers are mixed, the tensile strength is increased but the tensile elongation is lowered.

Therefore, there is a need to develop a new polymer composite material that increases the tensile strength and the tensile elongation at the same time as the tensile strength, which could not be obtained in the past, even though the composite material is manufactured by adding fibers. There is a demand for the development of composite materials.

Conventionally, when tensile strength is improved by fiber composite, it has been difficult to solve the problem of lowering tensile elongation. development is needed for

Republic of Korea Patent Publication No. 10-2013-0111935 (2013.10.11)

An object of the present invention is to provide a composite material in which tensile strength is increased as well as tensile elongation is simultaneously increased by fiber composite.

In addition, it is intended to provide a new composite material in which the increase rate of tensile strength and the increase rate of tensile elongation are more significantly increased by fiber composite.

As a result of research to achieve the above object, the present inventors put an arylene ether-based polymer or an arylene ether-imide-based polymer in a polar aprotic solution in which aramid nanofibers are dispersed, and solution blending to prepare a composite material or , by introducing a monomer to prepare a composite material in an in-situ method, despite the use of a remarkably small amount of aramid nanofibers, for example, despite the use of 0.01 to 2 wt% of the total composite material, mechanical properties It was found that it can significantly increase and completed. More specifically, it has been found and completed that it is possible to provide a composite material in which not only the increase in tensile strength but also the tensile elongation lowered by fiber composite can be simultaneously increased.

That is, in the polar aprotic solution in which the aramid nanofibers prepared according to the preparation method of the aramid nanofiber dispersion of Korean Patent Application No. 10-2018-0057585 (2018.05.21) previously applied by the present applicant are dispersed, an arylene ether-based solution Aramid with significantly improved mechanical properties to an unexpected degree by dissolving a polymer or arylene ether imide-based polymer or preparing a composite material in-situ by adding a monomer to a solution in which the aramid nanofibers are dispersed A nanofiber-arylene ether-based or arylene ether-imide-based polymer composite material was prepared.

In one aspect of the present invention for achieving the above object, an arylene ether-based polymer or an arylene ether-based polymer is added to a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent and dissolved therein. It is a method of manufacturing a polymer composite material by a solution blending method.

In another aspect of the present invention, in a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent, a monomer for preparing an arylene ether-based polymer or an arylene ether-imide-based polymer is mixed and polymerized to in-situ It is a method for manufacturing a polymer composite material by a method.

Another aspect of the present invention is a composite material containing aramid nanofibers in a polymer selected from an arylene ether-based polymer or an arylene ether-imide-based polymer, wherein the composite material has a tensile strength increase rate of 110% according to Equation 1 below Above, it is a polymer composite material having a tensile elongation increase rate of 110% or more according to Equation 2 below.

[Formula 1]

The TS ₀ is the tensile strength (MPa) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and TS ₁ is the tensile strength (MPa) of the composite material including the aramid nanofiber. . The tensile strength is measured according to ASTM D638.

[Formula 2]

The Te ₀ is the tensile elongation (%) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and Te ₁ is the tensile elongation (%) of the composite material containing the aramid nanofibers. . The tensile elongation is measured according to ASTM D638.

In the polymer composite material according to the present invention, the aramid nanofibers are uniformly dispersed, and not only the tensile strength but also the tensile elongation is increased at the same time.

Specifically, the tensile strength increase rate is increased by 110% or more, 120% or more, 130% or more, preferably 170% or more, more preferably 200% or more, and at the same time, the tensile elongation increase rate is 110% or more, 120% or more, 130% or more It is possible to provide a composite material that can achieve more than 140%, more than 150%, very preferably more than 200%.

In general, in the case of a fiber-dispersed composite material, tensile strength is increased, but tensile elongation is lowered, whereas in the present invention, a composite material is prepared using a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent. and tensile elongation can be simultaneously increased. In addition, the degree of increase has a very remarkable effect.

For example, the tensile elongation increase rate of the arylene ether-based composite material manufactured by the in-situ method can achieve excellent mechanical properties of 150% or more, preferably 170% or more, and more preferably 200% or more.

1 is a tensile graph of the arylene ether-based polymer specimen obtained in Comparative Examples 1 and 5 for comparison of the effect of reinforcing properties of aramid nanofibers.

Hereinafter, the present invention will be described in more detail through embodiments or examples including the accompanying drawings. However, the following examples are only a reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Also, unless defined otherwise, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of effectively describing particular embodiments only, and is not intended to limit the invention.

In the present invention, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

One aspect of the present invention is a polymer by a solution blending method comprising the step of dissolving an arylene ether-based polymer or an arylene ether-imide-based polymer in a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent To provide a method for manufacturing a composite material.

Another aspect of the present invention is a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent, mixing and polymerizing a monomer for preparing an arylene ether-based polymer or an arylene ether-imide-based polymer It is to provide a method for manufacturing a polymer composite material by an in-situ method.

In addition, an aspect of the present invention is a composite material containing aramid nanofibers in a polymer selected from arylene ether-based polymers or arylene ether-imide-based polymers, wherein the composite material has both tensile strength and tensile elongation of the aramid nanofibers. It is to provide a polymer composite material that increases by more than 110% compared to a polymer that does not contain it. Specifically, the composite material is a polymer composite material having a tensile strength increase rate of 110% or more according to Equation 1 below, and a tensile elongation rate increase rate of 110% or more according to Equation 2 below.

[Formula 1]

The TS ₀ is the tensile strength (MPa) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and TS ₁ is the tensile strength (MPa) of the composite material including the aramid nanofiber. . The tensile strength is measured according to ASTM D638.

[Formula 2]

The Te ₀ is the tensile elongation (%) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and Te ₁ is the tensile elongation (%) of the composite material containing the aramid nanofibers. . The tensile elongation is measured according to ASTM D638.

In one aspect, the polymer composite material may include 0.01 to 2 parts by weight of aramid nanofibers based on 100 parts by weight of the polymer.

In one aspect, the polymer composite material may have a tensile strength increase rate of 130% or more and a tensile elongation rate increase rate of 140% or more.

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

[Nanofiber Dispersion]

In one aspect of the present invention, the nanofiber dispersion may be one in which bulk aramid fibers, for example, Kevlar fibers, are dispersed in a polar aprotic solvent. More specifically, it is possible to prepare a dispersion in which aramid nanofibers are dispersed by stirring in a mixed state of aramid bulk fibers and a basic material in a polar aprotic solvent.

The aprotic polar solvent is specifically, for example, dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), hexamethylphosphoamide ( HMPA), N,N,N',N'-tetramethyl urea (TMU), and N,N-dimethylformamide (DMF) may be any one or a mixed solvent of two or more.

Specifically, the base material may be, for example, a strong base such as potassium hydroxide and sodium hydroxide, but is not limited thereto.

In another aspect of the present invention, the nanofiber dispersion may be prepared according to the method for preparing an aramid nanofiber dispersion of Korean Patent Application No. 10-2018-0057585 (2018.05.21) previously filed by the present applicant. More specifically, while dissolving or dispersing the aromatic polyamide-based polymer in a solution containing a basic material and an aprotic polar solvent, it may be prepared by stirring to induce nanofibers.

More specifically, the method for preparing the aramid nanofiber dispersion comprises the step of dissolving or dispersing the aromatic polyamide-based polymer in a solution containing a basic material and an aprotic polar solvent, while stirring to induce nanofibers. it could be Aramid nanofibers according to an embodiment are obtained by filtering the aramid nanofiber dispersion prepared by the above manufacturing method, and may have an average diameter of 1 to 100 nm, and an average length of 0.1 to 100 μm. In addition, the surface may be negatively charged, and it is distinguished from nanofibers produced by electrospinning.

The 'aromatic polyamide-based polymer' may be a purified polymer from which the organic solvent and side reactants used as reaction raw materials are removed during the preparation of the polymer, or may be a mixed composition in which the organic solvent and side reactants are not removed. The organic solvent contained in the mixed composition may be one used as a co-solvent when preparing an aramid nanofiber dispersion.

The method for preparing an aramid nanofiber dispersion according to an embodiment may be to prepare the nanofibers while stirring the aromatic polyamide-based polymer until completely dissolved or dispersed in a solution containing a basic material and an aprotic polar solvent.

More specifically, while dissolving or dispersing the aromatic polyamide-based polymer in a solution containing a basic material and an aprotic polar solvent, it may include stirring to induce nanofibers. In this case, nanofibers may be formed by self-assembly in the process of dissolving or dispersing, and sufficient time may be required for nanofibers to be formed. More specifically, it may be that the aromatic polyamide-based polymer is completely dissolved until invisible to the naked eye, and is generated into nanofibers by self-assembly and dispersed in a solution. In addition, although the self-assembly time is given, it is characterized in that this time is minimized.

In addition, the term self-assembly is a term that comprehensively expresses a phenomenon in which nanofibers are formed by dissolving or dispersing an aromatic polyamide-based polymer in a solvent.

The aprotic polar solvent used to prepare the nanofiber by dissolving the aromatic polyamide-based polymer is specifically, for example, dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), hexamethylphosphoamide (HMPA), N,N,N',N'-tetramethyl urea (TMU) and N,N-dimethylformamide (DMF) It may be any one or a mixed solvent of two or more. More specifically, for example, dimethyl sulfoxide (DMSO) is used alone, or dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), Any one or two or more cosolvents selected from hexamethylphosphoamide (HMPA), N,N,N',N'-tetramethyl urea (TMU) and N,N-dimethylformamide (DMF) are mixed and used may be doing By mixing and using the co-solvent, the time required to prepare the nanofiber compared to using dimethyl sulfoxide (DMSO) alone, that is, the amount of time required to dissolve the aromatic polyamide-based polymer until invisible to the naked eye The time may be further shortened.

Specifically, the base material may be, for example, a strong base such as potassium hydroxide and sodium hydroxide, but is not limited thereto.

Stirring may be performed to better dissolve the aromatic polyamide-based polymer, and the stirring may be performed at a temperature of 50° C. or less, more specifically 10 to 50° C., more specifically 20 to 30 It may be carried out at a temperature of ℃. In addition, the stirring may be in an inert gas atmosphere such as nitrogen or argon during the stirring, but is not limited thereto. In addition, the stirring may be performed at 10 ~ 1000 rpm, specifically 50 ~ 800 rpm, more specifically 100 ~ 500 rpm, but is not limited thereto.

The aromatic polyamide-based polymer refers to a solid polymer that is not spun into fibers. More specifically, it may be in a formless solid form that is not processed into a fiber form of 10 denier or less on a single fiber basis.

In one embodiment, the aromatic polyamide-based polymer may be filtered and purified after polymerization of a polymerization composition including an organic solvent, an aromatic diamine, and an aromatic diecide-based compound.

[Arylene Ether-Based Polymer]

In one aspect of the present invention, the arylene ether-based polymer is not particularly limited as long as it is a polymer having an arylene ether structure. have.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

In one aspect, the molecular weight of the arylene ether-based polymer is not particularly limited, but specifically, for example, may have a weight average molecular weight of 10,000 to 300,000 g/mol. In the case of a polymer having a weight average molecular weight in the above range, tensile strength and elongation can be remarkably improved when prepared with aramid nanofibers and composite materials.

[Arylene ether imide-based polymer]

In one aspect of the present invention, the arylene ether imide-based polymer is not particularly limited as long as it is a polymer having an arylene ether imide-based structure. for example.

[Formula 8]

[Formula 9]

In one aspect, the molecular weight of the arylene ether imide-based polymer is not particularly limited, but specifically, for example, may have a weight average molecular weight of 10,000 to 300,000 g/mol. In the case of a polymer having a weight average molecular weight in the above range, tensile strength and elongation can be remarkably improved when prepared with aramid nanofibers and composite materials.

[Solution blending method]

In one aspect of the present invention, the method for producing a polymer composite material by a solution blending method is

a) dissolving an arylene ether-based polymer or an arylene ether-imide-based polymer in a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent;

b) drying the solvent;

may include.

By drying the solvent, it is possible to obtain a composite material in a solid powder state, and the process of melting and molding it may be further included.

The method of dissolving the arylene ether-based polymer or the arylene ether imide-based polymer in the nanofiber dispersion in step a) is not particularly limited, but for example, ultrasonic dispersion and mechanical stirring during mixing and dispersing. Available.

In one aspect, the solid content of the nanofiber dispersion in step a) may be 0.1 to 1% by weight. In addition, the nanofiber dispersion may be used in an amount of 10 to 50 parts by weight based on 100 parts by weight of the polymer, and in order to further improve dispersibility, 500 to 1500 parts by weight of an additional polar aprotic solvent may be further added and mixed. have.

In one aspect, the arylene ether-based composite material prepared by the solution blending method has a tensile strength increase rate of 110% or more, preferably 120% or more, more preferably 140% or more, according to the following formula 1, according to the following formula 2 Accordingly, the tensile elongation increase rate may be 110% or more, preferably 120% or more, and more preferably, it may have a high increase effect of 130% or more.

[Formula 1]

The TS ₀ is the tensile strength (MPa) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and TS ₁ is the tensile strength (MPa) of the composite material including the aramid nanofiber. . The tensile strength is measured according to ASTM D638.

[Formula 2]

The Te ₀ is the tensile elongation (%) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and Te ₁ is the tensile elongation (%) of the composite material containing the aramid nanofibers. . The tensile elongation is measured according to ASTM D638.

In one embodiment, the polar aprotic solvent is dimethylsulfoxide (DMSO), dimethylacetamide (DMAc), dimethylformamide (DMF), methylpyrrolidone (NMP), sulfolane and N-cyclohexyl. It may be any one or a mixture of two or more selected from the group consisting of -2-methylpyrrolidone (N-cyclohexyl-2-pyrrolidone), and the like, but is not limited thereto.

In one aspect, the aramid nanofibers are not particularly limited, but may have an average diameter of 1 to 200 nm, and more preferably 3 to 100 nm. In addition, the average length may be a fiber of 0.05 to 200 μm, more preferably 0.1 to 100 μm, but is not limited thereto. When the aramid nanofibers in the above range are included, the dispersibility is excellent, and thus, when it is made of an arylene ether-based polymer and a composite material, it is preferable because the synergistic effect of mechanical properties, particularly tensile strength and tensile elongation, is superior.

In one aspect, the aramid nanofiber may be included in an amount of 0.0001 to 10 parts by weight based on 100 parts by weight of the polymer. Preferably, it may be included in an amount of 0.001 to 5 parts by weight, and more preferably, it may be included in an amount of 0.01 to 2 parts by weight.

In the present invention, the aramid nanofiber is a nanofiber prepared in a nano size in a polar aprotic solvent containing an alkali metal basic compound from a bulk fiber prepared by the conventional sulfuric acid method, or Korea Application No. 10-2018 previously filed by the present inventors Aramid nanofibers prepared by the method described in -0057585 can be used. In the present invention, it does not matter which method is produced by any of the above methods, but in the case of preparing aramid nanofibers directly from the polymer invented by the present inventor, a large amount of aramid nanofibers can be obtained in a short time, and the production of aramid nanofibers itself The solution can be used for solution blending with the arylene ether-based polymer.

[in-situ law]

In another aspect of the present invention, an arylene ether-based or arylene ether-imide-based polymerization monomer is mixed with a polar aprotic solution in which aramid nanofibers are dispersed and polymerized to prepare in-situ arylene To provide a method for manufacturing an ether-based polymer composite material. When explaining the case of manufacturing a composite material by the in-situ method, the arylene ether-based or arylene ether-imide-based polymerization monomer is mixed with a polar aprotic solution in which the aramid nanofibers are dispersed, and the polymerization is performed. It refers to the process of manufacturing a composite material, and it is not necessary to dissolve the polymerized polymer separately, so the composite material can be manufactured conveniently.

More specifically,

i) preparing a mixture in which a monomer for preparing an arylene ether-based polymer or an arylene ether-imide-based polymer is mixed in a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent;

ii) polymerizing the mixture;

may include.

In one aspect, the monomer of step i) may be used without limitation as long as it is a monomer for preparing an arylene ether-based polymer or an arylene ether-based polymer. Specifically, for example, bisphenol-A and 4,4′-difluorodiphenyl sulfone may be exemplified as a monomer for preparing the arylene ether-based polymer, but the present invention is not limited thereto. Examples of the monomer for preparing the arylene ether imide-based polymer include 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride and 1,4-phenylenedimine may, but is not limited thereto.

In one aspect, the solid content of the nanofiber dispersion in step i) may be 0.1 to 1% by weight. In addition, the nanofiber dispersion may be used in an amount of 10 to 50 parts by weight based on 100 parts by weight of the total content of the monomer, and 500 to 1500 parts by weight of an additional polar aprotic solvent to further improve dispersibility. It may be mixing.

In one embodiment, the polar aprotic solvent is dimethylsulfoxide (DMSO), dimethylacetamide (DMAc), dimethylformamide (DMF), methylpyrrolidone (NMP), sulfolane and N-cyclohexyl. It may be any one or a mixture of two or more selected from the group consisting of -2-methylpyrrolidone (N-cyclohexyl-2-pyrrolidone), and the like, but is not limited thereto.

The dispersibility may be further improved by performing ultrasonication of the mixture before polymerization in step ii).

The polymerization may be carried out according to a conventional polymerization method.

The composite material manufactured by the in-situ method has a tensile strength increase rate of 120% or more, preferably 160% or more, more preferably 200% or more according to Equation 1 below, and a tensile elongation increase rate according to Equation 2 below is 150% or more , preferably 170% or more, more preferably 230% or more.

[Formula 1]

The TS ₀ is the tensile strength (MPa) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and TS ₁ is the tensile strength (MPa) of the composite material including the aramid nanofiber. . The tensile strength is measured according to ASTM D638.

[Formula 2]

The Te ₀ is the tensile elongation (%) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and Te ₁ is the tensile elongation (%) of the composite material containing the aramid nanofibers. . The tensile elongation is measured according to ASTM D638.

In one aspect, the aramid nanofibers are not particularly limited, but may have an average diameter of 1 to 200 nm, and more preferably 3 to 100 nm. In addition, it may be a fiber having an average length of 0.05 to 200 μm, more preferably 0.1 to 100 μm, but is not limited thereto. When the aramid nanofibers in the above range are included, the dispersibility is excellent, and accordingly, when it is made of an arylene ether-based polymer and a composite material, it is preferable because the synergistic effect of mechanical properties, particularly tensile strength and tensile elongation, is superior.

In one aspect, the aramid nanofiber may be included in an amount of 0.0001 to 10 parts by weight based on 100 parts by weight of the polymer. Preferably, it may be included in an amount of 0.001 to 5 parts by weight, and more preferably, it may be included in an amount of 0.01 to 2 parts by weight.

In the present invention, it does not matter which method is produced by any of the above methods, but in the case of producing aramid nanofibers directly from the polymer invented by the present inventor, a large amount of aramid nanofibers can be obtained in a short time, and the production of aramid nanofibers itself The solution can be used for blending the solution with the arylene ether-based polymer, and it is more preferred because the arylene ether monomer can be added to the solution and dissolved to produce a composite material directly in-situ.

Another aspect of the present invention, by the in-situ method, mixing an arylene ether- or arylene ether-imide-based polymerization monomer in a polar aprotic solution in which aramid nanofibers are dispersed and polymerizing it to prepare a composite material, In addition, it is also possible to prepare a composite material by dispersing the pre-prepared aramid nanofibers in a solution in which an arylene ether-based or arylene ether-imide-based monomer is mixed.

In another aspect of the present invention, when an arylene ether-based or arylene ether-imide-based composite material is prepared by in-situ method in a polar aprotic solution in which aramid nanofibers are dispersed, the arylene ether-based or arylene The molecular weight of the ether imide-based polymer is not particularly limited, but specifically, for example, a weight average molecular weight of 10,000 to 300,000 g/mol may be satisfied, but is not limited thereto. The composite material prepared by the method comprising the step of mixing and polymerizing the aramid nanofiber dispersion and the arylene ether-based or arylene ether imide-based polymerization monomer in the polar aprotic solution as described above has a weight average molecular weight in the same range When included, it is possible to significantly improve the tensile strength and elongation of the composite material.

When the arylene ether-based composite material is manufactured by the in-situ method, the tensile strength increase rate may satisfy 120% or more. Moreover, when an arylene ether-based monomer is mixed and polymerized in a polar aprotic solution in which aramid nanofibers are dispersed to produce an arylene ether-based composite material, 160% or more, preferably 200% or more, can be satisfied. desirable.

In addition, at the same time as the increase in tensile strength, the tensile elongation is preferably 140% or more, 160% or more, preferably 200% or more can be satisfied.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the following Examples and Comparative Examples are only examples for explaining the present invention in more detail, and the present invention is not limited by the following Examples and Comparative Examples.

[Method of measuring physical properties]

(1) Tensile strength, tensile elongation

The prepared polymer composite material was melt-injected into a dumbbell-shape according to ASTM D638-Type 1, and then a tensile test was performed according to ASTM D638 using UTM 5942 (INSTRON). As the result value, the average of the values measured four or more times was used.

The tensile strength increase rate (%) was calculated by using the following formula 1 to calculate the increase rate compared to the tensile strength of the arylene ether-based or arylene ether imide-based polymer corresponding to Comparative Example 1.

[Formula 1]

In the above formula 1,

The TS ₀ is the tensile strength (MPa) of an arylene ether-based or arylene ether imide-based polymer that does not contain aramid nanofibers, and TS ₁ is an arylene ether-based arylene ether-based solution in a polar aprotic solution in which the aramid nanofibers are dispersed. Or the tensile strength (MPa) of the composite material prepared by adding an arylene ether imide-based polymer.

The tensile elongation increase rate (%) was calculated by calculating the increase rate compared to the tensile elongation rate of the arylene ether-based or arylene ether imide-based polymer corresponding to Comparative Example 1 through Equation 2 below.

[Formula 2]

In the above formula 2,

The Te ₀ is the tensile elongation (%) of the arylene ether-based or arylene ether imide-based polymer that does not contain aramid nanofibers, and Te ₁ is an arylene ether-based or arylene ether imide-based polymer containing aramid nanofibers. It is the tensile elongation (%) of the polymer composite material.

(2) Weight average molecular weight and molecular weight distribution

The weight average molecular weight was obtained as a standard polystyrene equivalent molecular weight value and molecular weight distribution by gel permeation chromatography (GPC) measurement equipped with a refractive index sensor using chloroform as a solvent.

GPC Equipment: Waters' ACQUITY APC

Column: ACQUITY APC ^TM from Waters

Column temperature: 30 °C

Input amount: 50 μl

Flow rate: 0.62 ml/min

[Preparation Example 1] Preparation of nanofiber dispersion

2 g of aramid bulk fiber (Kevlar), 3 g of KOH, and 1000 g of dimethylsulfoxide (DMSO) were added to 2500 mL of dried glass glass and stirred at 25° C. for 180 hours. A nanofiber dispersion in which 0.2% by weight of aramid nanofibers were dispersed was prepared. The aramid nanofibers in the prepared nanofiber dispersion had an average diameter of 20 nm and an average length of 30 μm.

[Preparation Example 2] Preparation of aramid nanofiber solid powder

The aramid nanofiber dispersion of Preparation Example 1 was precipitated in methanol, filtered and vacuum dried to obtain an aramid nanofiber solid powder.

[Preparation Example 3] Preparation of arylene ether-based polymer

51.6 g (0.226 mol) of Bisphenol-A, 4,4'-difluoromethyl phenyl sulfone (4,4'-) in a glass flask equipped with a mechanical stirrer and Dean-Stark apparatus 57.5 g (0.226 mol) of difluorodiphenyl sulfone) and 44.5 g (0.0322 mol) of potassium carbonate were added. Then, 3.0 g of 18-crown-6 (18-crown-6) and 350 g of dimethyl sulfoxide (DMSO) of 0.05 molar equivalent to Bisphenol-A were added, followed by nitrogen purge. The reaction mixture was sonicated for 10 min and then heated at 155 °C for 4 h under a nitrogen atmosphere. After polymerization, the reaction mixture was diluted with 200 ml of DMSO, cooled to room temperature and precipitated in 1 L (50/50 vol %) of a water/methanol mixture containing 100 ml of acetic acid. To remove residual additives, the solid was filtered, dissolved in N,N'-dimethylacetamide (DMAc), and reprecipitated. The precipitated polymer was filtered, washed with deionized water and methanol, and vacuum dried at 80 °C for 12 hours. The weight average molecular weight was 122,000 g/mol, and the molecular weight distribution was 2.02.

In order to measure the mechanical properties of the prepared arylene ether-based polymer, the prepared polymer was melted at 270° C. for 8 minutes, and then, using Haake ^TM Minijet (Thermo Scientific), the length, width and thickness were 63.50 mm, respectively, Dumbbell-shaped specimens measuring 9.53 mm and 3.18 mm were molded. The cylinder temperature was 300 °C, the injection pressure was 500 bar, the filling time was 15 seconds, and the mold temperature was 230 °C. Table 1 shows the measurement results of physical properties.

[Preparation Example 4] Preparation of arylene ether imide-based polymer

2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride 117.6g (0.226mol), 1,4-phenylene diamine 24.4g in a stirred reactor having a reflux device (0.226 mol) and 410 g of N-methyl-2-pyrrolidone (NMP) and 10 mL of chlorobenzene were added under a nitrogen atmosphere.

The reaction mixture was heated at 190° C. for 8 hours under a nitrogen atmosphere. Chlorobenzene was periodically removed by a Dean-stark trap, and additional dry chlorobenzene was added to promote the cyclodehydration reaction. After polymerization, the reaction mixture was diluted with 200 ml of NMP, cooled to room temperature and precipitated in 10 L (50/50 vol %) of a water/methanol mixture containing 100 ml of acetic acid. The precipitated polymer was filtered, washed with deionized water and methanol, and vacuum dried at 80 °C for 12 hours. The weight average molecular weight was 62,000 g/mol, and the molecular weight distribution was 2.01.

To measure the mechanical properties of the prepared arylene ether imide-based polymer, the obtained polymer was melted at 370° C. for 8 minutes, and then the length, width, and thickness were 63.50 mm and 9.53 mm using Haake ^TM Minijet (Thermo Scientific), respectively. and a 3.18 mm dumbbell-shaped specimen. The cylinder temperature was 400 °C, the injection pressure was 500 bar, the filling time was 15 seconds, and the mold temperature was 280 °C. The measurement results of physical properties are listed in Table 2.

[Comparative Example 1]

0.05 g of the solid aramid nanofiber of Preparation Example 2, 100 g of the arylene ether-based polymer prepared in Preparation Example 3, and 10 g of dioctyl terephthalate were dissolved and dispersed in 1000 g of dimethylacetamide (DMAc). . Each solution was then dried in a convection oven at 100 °C for 3 days. The dried solid powder was prepared in the same manner as the preparation conditions of the specimen described in Preparation Example 3, and the physical properties were measured and recorded in Table 1.

[Example 1]

With respect to 100 parts by weight of the polymer, an arylene ether-based composite material containing 0.05 parts by weight of aramid nanofibers was prepared by a solution blending method as follows.

100 g of the arylene ether-based polymer of Preparation Example 3, 10 g of dioctyl terephthalate, and 25 g of the nanofiber dispersion of Preparation Example 1 (in which 0.05 g of aramid nanofibers are dispersed) 1000 g of dimethylacetamide (DMAc) was dissolved in Each solution was then dried in a convection oven at 100 °C for 3 days. After melting at 270 ° C. for 8 minutes to measure the mechanical properties of the arylene ether-based composite material prepared above, the length, width and thickness were 63.50 mm, ^9.53 mm and A 3.18 mm dumbbell-shaped specimen was molded. The cylinder temperature was 300 °C, the injection pressure was 500 bar, the filling time was 15 seconds, and the mold temperature was 230 °C. The physical properties were measured using the specimens and are listed in Table 1.

[Example 2]

It was prepared in the same manner as in Example 1, but with respect to 100 parts by weight of the polymer, a composite material containing 0.2 parts by weight of aramid nanofibers was prepared. Specimens were prepared under the same conditions as in Example 1, and their physical properties were measured and listed in Table 1.

[Example 3]

Prepared in the same manner as in Example 1, but with respect to 100 parts by weight of the polymer, a composite material containing 1 part by weight of aramid nanofibers was prepared. included.

[Example 4]

Based on 100 parts by weight of the polymer, an arylene ether-based composite material containing 0.05 parts by weight of aramid nanofibers was prepared in-situ.

Instead of 350 g of dimethyl sulfoxide (DMSO) as a solvent, a mixed solvent of 25 g of the nanofiber dispersion of Preparation Example 1 (in which 0.05 g of aramid nanofibers are dispersed) and 325 g of dimethyl sulfoxide (DMSO) was used as a polymerization solvent Except that, the polymerization process was performed in the same manner as in Preparation Example 3 to prepare a composite material. At this time, the polymer had a weight average molecular weight of 110,000 g/mol and a molecular weight distribution of 1.98.

After drying the composite material, a specimen for measuring mechanical properties was prepared according to the melt injection conditions of Preparation Example 3. When preparing the specimen, 10 wt% of a dioctyl terephthalate plasticizer was added based on the weight of the dried composite material solid powder. The physical properties were measured using the specimens and are listed in Table 1.

[Example 5]

Polymerized in the same manner as in Example 4, but based on 100 parts by weight of the polymer, a composite material containing aramid nanofibers in an amount of 0.2 parts by weight was prepared. (weight average molecular weight: 100,500 g/mol, molecular weight distribution: 1.92). A specimen was prepared in the same manner as in Example 4, and its physical properties were measured and recorded in Table 1.

[Example 6]

Polymerized in the same manner as in Example 4, but with respect to 100 parts by weight of the polymer, a composite material containing 1 part by weight of aramid nanofibers was prepared. (weight average molecular weight: 100,200 g/mol, molecular weight distribution: 1.88). A specimen was prepared in the same manner as in Example 4, and its physical properties were measured and recorded in Table 1.

[Example 7]

With respect to 100 parts by weight of the polymer, an arylene ether imide-based composite material containing 0.05 parts by weight of aramid nanofibers was prepared by a solution blending method as follows.

100 g of the arylene ether imide-based polymer prepared in Preparation Example 4, 10 g of dioctyl terephthalate, and 25 g of the nanofiber dispersion of Preparation Example 1 (aramid nanofibers are dispersed in 0.05 g) with N-methyl-2 - It was dissolved in 1000 g of pyrrolidone (NMP). The solution was then dried in a convection oven at 150 °C for 3 days. The dried solid powder was prepared and analyzed in the same manner as the specimen preparation conditions of Preparation Example 4, and the results are listed in Table 2.

[Example 8]

Based on 100 parts by weight of the polymer, an arylene ether imide-based composite material containing 0.05 parts by weight of aramid nanofibers was prepared by the in-situ method as follows.

Follow the arylene ether imide-based polymer synthesis process of Preparation Example 4, but instead of 410 g of the polymerization solvent N-methyl-2-pyrrolidone (NMP), 25 g of the nanofiber dispersion of Preparation Example 1 (0.05 g of aramid nanofibers) Dispersion) and a mixed solvent of 385 g of N-methyl-2-pyrrolidone (NMP) were used as polymerization solvents to carry out the same polymerization process. (weight average molecular weight: 58,000 g/mol, molecular weight distribution: 1.98)

The dried composite material solid powder was prepared in the same manner as the specimen preparation conditions of Preparation Example 4, and the physical properties were measured and listed in Table 2. Dioctyl terephthalate plasticizer was added in an amount of 10 wt% based on the weight of the dried composite material solid powder.

content
(parts by weight) The tensile strength
(MPa) Tensile strength increase rate
(%) Elongation (%) elongation rate increase
(%) Preparation 3 - 45 - 13 - Example 1 0.05 52 115 15 115 Example 2 0.2 58 129 17 131 Example 3 One 63 141 16 123 Example 4 0.05 61 135 20 154 Example 5 0.2 78 173 30 231 Example 6 One 96 213 22 169 Comparative Example 1 0.05 30 67 3 23

content
(parts by weight) The tensile strength
(MPa) Tensile strength increase rate
(%) Elongation (%) elongation rate increase
(%) Preparation 4 - 80 - 25 - Example 7 0.05 96 120 29 115 Example 8 0.05 108 135 35 140

As shown in Tables 1 and 2, it can be seen that the tensile strength and tensile elongation of the arylene ether-based or arylene ether imide-based polymer composite material containing the aramid nanofibers according to the present invention are simultaneously increased, and also the aramid nanofibers. It can be seen that, compared to the polymer that does not contain the fiber, it is significantly increased.

Furthermore, it can be confirmed that when the content of aramid nanofibers is contained in an amount of 0.05 to 1 part by weight compared to 100 parts by weight of the arylene ether-based or arylene ether-imide-based polymer in the composite material, a synergistic effect of better mechanical properties can be realized. .

In addition, when the arylene ether-based polymer is solution-blended in a solution in which the aramid nanofibers are dispersed according to the present invention or a composite material is prepared by an in-situ method, the masterbatch complex is added to the aramid nanofiber powder prepared in the present invention. It can be seen that mechanical properties such as tensile strength and tensile elongation are much higher than when the composite material is prepared by melt-kneading.

Furthermore, in the case of preparing an arylene ether-based or arylene ether imide-based masterbatch complex from a monomer in-situ by using the solution in which the aramid nanofibers are dispersed according to the present invention as a polymerization solvent, the masterbatch by solution blending method It can be seen that a synergistic effect of mechanical properties better than that of manufacturing a composite can be implemented.

The present invention described above is merely exemplary, and those of ordinary skill in the art to which the present invention pertains will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, it will be well understood that the present invention is not limited to the form mentioned in the above detailed description. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims to be described later, but also all those with equivalent or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

Claims (12)

A solution blending method comprising the step of dissolving an arylene ether-based polymer or an arylene ether-imide-based polymer in a nanofiber dispersion in which aramid nanofibers and a base material are dispersed in a polar aprotic solvent; or
In-situ method comprising the step of mixing and polymerizing a nanofiber dispersion in which aramid nanofibers are dispersed in a polar aprotic solvent, and a monomer for preparing an arylene ether-based polymer or an arylene ether-imide-based polymer;
Method for producing a polymer composite material selected from. The method of claim 1,
The polymer composite material has a tensile strength increase rate of 110% or more according to Equation 1 below, and a tensile elongation rate increase rate of 110% or more according to Equation 2 below.
[Formula 1]

The TS ₀ is the tensile strength (MPa) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and TS ₁ is the tensile strength (MPa) of the composite material including the aramid nanofiber. . The tensile strength is measured according to ASTM D638.
[Formula 2]

The Te ₀ is the tensile elongation (%) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and Te ₁ is the tensile elongation (%) of the composite material containing the aramid nanofibers. . The tensile elongation is measured according to ASTM D638. The method of claim 1,
The arylene ether-based polymer is a method for producing a polymer composite material containing a repeating unit of the following structure.
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

The method of claim 1,
The arylene ether imide-based polymer is a method for producing a polymer composite material containing a repeating unit of the structure:
[Formula 8]

[Formula 9]

The method of claim 1,
The polar aprotic solvent is any one or a mixture of two or more selected from the group consisting of dimethylsulfoxide, dimethylacetamide, dimethylformamide, methylpyrrolidone, sulfolane and N-cyclohexyl-2-methylpyrrolidone. A method for producing a phosphorus polymer composite material. The method of claim 1,
The average diameter of the aramid nanofibers is 3 to 100 nm, the average length of the method for producing a polymer composite material of 0.1 to 100 ㎛. The method of claim 1,
The aramid nanofiber is a method for producing a polymer composite material containing 0.01 to 2 parts by weight based on 100 parts by weight of the polymer constituting the composite material. The method of claim 1,
The nanofiber dispersion is a polymer composite material prepared by dissolving or dispersing the aromatic polyamide-based polymer in a solution containing a base material and an aprotic polar solvent, and stirring to induce nanofibers. manufacturing method. 9. The method of claim 8,
The stirring is a method for producing a polymer composite material that is performed at a temperature of 50 ℃ or less. As a composite material containing aramid nanofibers in a polymer selected from arylene ether-based polymers or arylene ether-imide-based polymers,
The composite material has a tensile strength increase rate of 110% or more according to Equation 1 below, and a tensile elongation rate increase rate of 110% or more according to Equation 2 below.
[Formula 1]

The TS ₀ is the tensile strength (MPa) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and TS ₁ is the tensile strength (MPa) of the composite material including the aramid nanofiber. . The tensile strength is measured according to ASTM D638.
[Formula 2]

The Te ₀ is the tensile elongation (%) of the arylene ether-based polymer or the arylene ether imide-based polymer that does not contain aramid nanofibers, and Te ₁ is the tensile elongation (%) of the composite material containing the aramid nanofibers. . The tensile elongation is measured according to ASTM D638. 11. The method of claim 10,
The aramid nanofiber is a polymer composite material that is included in 0.01 to 2 parts by weight with respect to 100 parts by weight of the polymer constituting the composite material. 11. The method of claim 10,
The polymer composite material has a tensile strength increase rate of 130% or more, and a tensile elongation rate increase rate of 140% or more.

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