Self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion and preparation method and application thereof

Abstract

The invention discloses self-lubricating flame-retardant epoxy resin for pultrusion of basalt fibers as well as a preparation method and application of the self-lubricating flame-retardant epoxy resin, and relates to the technical field of high polymer materials. The self-lubricating flame-retardant epoxy resin is prepared from the following raw materials in parts by mass: 100 parts of a phenolic aldehyde modified epoxy resin solution, 0.5-2 parts of a silane coupling agent, 2-8 parts of modified graphite powder, 20-30 parts of modified nano aluminum hydroxide, 0.5-1.0 part of a plasticizer, 0.2-0.8 part of an accelerant and 10-15 parts of a diluent. The modified graphite powder and the modified nano aluminum hydroxide are used as inorganic inert fillers to synergistically modify the epoxy resin, so that the basalt fiber pultrusion sectional material has the characteristics of low friction coefficient, good flame retardance, high strength, good toughness and low shrinkage rate, is simple in preparation process and easy for industrial production, and has wide application prospects in the field of basalt fiber pultrusion sectional materials.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion molding, and a preparation method and application thereof. Background Art

[0002] The matrix materials used in basalt fiber reinforced composite materials are usually thermosetting epoxy resins, polyester unsaturated resins, vinyl resins, etc. Polyester unsaturated resins and vinyl resins contain a large amount of organic solvents. Epoxy resins themselves do not contain solvents, but solvents are added during the pultrusion process due to process requirements. Organic solvents are very dangerous during the production process and are easily volatilized into flammable gases, which are prone to deflagration, explosion, and fire.

[0003] The pultrusion process is an efficient and large-scale method for producing high-performance fiber composite materials. It is characterized by simple process and high efficiency, and is suitable for large-scale production of high-performance fiber composite materials. Basalt fiber is a new type of inorganic environmentally friendly green high-performance fiber material. It not only has high strength, but also has many excellent properties such as electrical insulation, corrosion resistance, and high temperature resistance. It has been widely used in pultruded profiles. Due to its high strength, high toughness, corrosion resistance and other properties, epoxy resin is often used as the matrix material of pultruded profiles. However, in practical applications, epoxy resin has some disadvantages. For example, its flame retardant performance is relatively low, and it is easy to burn when encountering a fire source. At the same time, the friction coefficient of epoxy resin is high. In the pultrusion process, an internal release agent is usually required so that the product can be easily removed from the mold to ensure the surface quality of the product and the integrity of the mold. However, the internal release agent is too acidic, which is easy to corrode the metal mold and shorten the mold life.

[0004] In order to overcome the defects of the prior art, the present invention provides a self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion molding and a preparation method and application thereof. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of the present invention is to provide a self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion molding and a preparation method and application thereof, so as to solve the problems that the solvent used in the existing basalt fiber pultrusion molding epoxy resin is flammable, has poor flame retardancy and a high friction coefficient.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] In the first aspect, a self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion molding comprises the following raw materials in parts by weight: 100 parts of phenolic modified epoxy resin solution, 0.5-2 parts of silane coupling agent, 2-8 parts of modified graphite powder, 20-30 parts of modified nano aluminum hydroxide, 0.5-1.0 parts of plasticizer, 0.2-0.8 parts of accelerator, and 10-15 parts of diluent.

[0008] Furthermore, the graphite powder modifier used in the modified graphite powder comprises the following raw materials in parts by mass: 5-30 parts of 1-7% hydrochloric acid solution, 0.5-8 parts of sodium lauryl sulfate, 0.3-0.6 parts of yttrium nitrate hexahydrate, and 0.1-1 parts of octadecyltrichlorosilane.

[0009] Furthermore, the modified graphite powder preparation method is as follows: adding sodium lauryl sulfate to a hydrochloric acid solution, then adding yttrium nitrate hexahydrate, and then adding octadecyltrichlorosilane, stirring and mixing thoroughly to obtain a graphite powder modifier; sending the graphite powder into the graphite powder modifier for ultrasonic treatment, and then washing with water and drying to obtain modified graphite powder.

[0010] Furthermore, the preparation method of the modified nano aluminum hydroxide is as follows:

[0011] S1: preparing a hexadecyltrimethoxysilane ethanol solution with a mass concentration of 20-40%;

[0012] S2: Add nano aluminum hydroxide and hexadecyltrimethoxysilane ethanol solution in a weight ratio of 100:0.1-5 into a ball mill and grind for 30-60 minutes. Dry the ground powder in a vacuum dryer at 60-100° C. for 2-3 hours to obtain modified nano aluminum hydroxide.

[0013] Furthermore, the preparation method of the phenolic modified epoxy resin solution is as follows:

[0014] Step (1): In a reaction vessel, phenol and NaOH solution are mixed and kept warm;

[0015] Step (2): continue to add formaldehyde solution and keep the temperature, add acrylic epoxy resin after the temperature rises and keep the temperature, then cool down, degas and discharge to obtain phenolic modified epoxy resin solution.

[0016] Furthermore, the mass ratio of the phenol, NaOH solution, formaldehyde solution and acrylic epoxy resin is (10-20):(1-2):(10-15):(20-30), the mass concentration of the NaOH solution is 32-34%; the mass concentration of the formaldehyde solution is 35-38%.

[0017] Furthermore, in step (1), the insulation temperature is 40-60°C and the time is 20-30 minutes;

[0018] And / or, in step (2), the insulation temperature after the addition of the formaldehyde solution is 60-75°C for 30-40 minutes; and / or, the heating temperature is increased to 75-85°C, and the insulation time after the addition of the acrylic epoxy resin is 20-30 minutes; and / or, the cooling temperature is decreased to 70-75°C; and / or, the degassing time is 10-15 minutes.

[0019] Further, the plasticizer includes propylene oxide, dibutyl succinate, dibenzyl benzoate, dioctyl phthalate, dibenzyl phthalate or di(2-ethylhexyl) phthalate;

[0020] and / or, the promoter comprises triethylamine, triethanolamine, BMDA, DBU, DMP-10 or pyridine;

[0021] and / or, the diluent comprises acetone, butanone or methyl propyl ketone;

[0022] And / or, the silane coupling agent is KH560, KH792, DL602 or DL171.

[0023] In a second aspect, a method for preparing a self-lubricating flame-retardant epoxy resin as described in the first aspect comprises: sequentially adding a silane coupling agent, modified graphite powder, modified nano-aluminum hydroxide, a plasticizer, a accelerator and a diluent to a phenolic modified epoxy resin solution, and stirring to obtain a self-lubricating flame-retardant epoxy resin; further, the stirring time is 10-20 minutes.

[0024] In a third aspect, a self-lubricating flame-retardant epoxy resin as described in the first aspect or a self-lubricating flame-retardant epoxy resin prepared by the preparation method as described in the second aspect is used as a basalt fiber pultrusion molding matrix material.

[0025] The present invention provides a self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion molding and a preparation method and application thereof, which have the advantages of:

[0026] The present invention adopts modified graphite powder as a self-lubricating filler added to epoxy resin. Due to the weak van der Waals force between graphite layers, the graphite powder can slide easily between its layers, which can ensure that the epoxy resin has the function of continuously reducing the friction coefficient during the pultrusion molding process, prolong the friction stability stage, and form a good friction transfer film between the product and the pultrusion metal mold, omitting the use of an internal release agent, avoiding the corrosion of the metal mold by its high acidity, and extending the mold life. At the same time, modified nano aluminum hydroxide is used as a flame retardant filler added to the epoxy resin. Nano aluminum hydroxide is a halogen-free environmentally friendly flame retardant, which can not only flame retardant, suppress smoke, and not produce molten droplets and toxic gases, but also help to improve the surface finish and mechanical and electrical properties of polymer products, and enhance their anti-leakage, arc resistance and wear resistance; therefore, nano aluminum hydroxide can not only increase the flame retardancy of epoxy resin, but also prevent the volatilization and explosion of solvents in the pultrusion process to a certain extent. The present invention uses modified graphite powder and modified nano aluminum hydroxide to synergistically modify epoxy resin. These two inorganic inert fillers do not participate in the curing reaction, can reduce the curing shrinkage rate, and can be closely combined with the matrix resin after modification to form a dense protective layer, thereby improving the cohesion, flame retardancy, lubrication and wear resistance of the epoxy resin.

[0027] The self-lubricating flame-retardant epoxy resin of the present invention imparts self-lubricating and flame-retardant properties to the epoxy resin, so that it has the characteristics of low friction coefficient, good flame retardancy, high strength, good toughness, low shrinkage, etc., and has a simple preparation process and is easy for industrial production, and has broad application prospects in the field of basalt fiber pultrusion profiles. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. The process parameters of the following embodiments that do not specify specific conditions are usually based on conventional conditions.

[0029] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0030] According to a first aspect of the present invention, a self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion molding comprises the following raw materials in parts by weight: 100 parts of phenolic modified epoxy resin solution, 0.5-2 parts of silane coupling agent, 2-8 parts of modified graphite powder, 20-30 parts of modified nano aluminum hydroxide, 0.5-1.0 parts of plasticizer, 0.2-0.8 parts of accelerator, and 10-15 parts of diluent.

[0031] The self-lubricating flame-retardant epoxy resin of the present invention imparts self-lubricating and flame-retardant properties to epoxy resin, and has the characteristics of low friction coefficient, good flame retardancy, high strength, good toughness, low shrinkage, etc., and has a simple preparation process and is easy for industrial production, and has broad application prospects in the field of basalt fiber pultrusion profiles.

[0032] The present invention adopts modified graphite powder as a self-lubricating filler added to epoxy resin. Due to the weak van der Waals force between graphite layers, the graphite powder can slide easily between its layers, which can ensure that the epoxy resin has the function of continuously reducing the friction coefficient during the pultrusion molding process, prolong the friction stability stage, and form a good friction transfer film between the product and the pultrusion metal mold. Due to the use of modified graphite powder, the use of internal release agent is omitted, and the corrosion of the metal mold by its high acidity is avoided, so that the mold life is extended. At the same time, modified nano aluminum hydroxide is used as a flame retardant filler added to the epoxy resin. Nano aluminum hydroxide is a halogen-free environmentally friendly flame retardant, which can not only flame retardant, smoke suppression, no molten droplets and toxic gases, but also help to improve the surface finish and mechanical and electrical properties of polymer products, and enhance their anti-leakage, arc resistance and wear resistance; therefore, nano aluminum hydroxide can not only increase the flame retardancy of epoxy resin, but also prevent the volatilization and explosion of solvents in the pultrusion process to a certain extent. The present invention uses modified graphite powder and modified nano aluminum hydroxide to synergistically modify epoxy resin. These two inorganic inert fillers do not participate in the curing reaction, can reduce the curing shrinkage rate, and can be closely combined with the matrix resin after modification to form a dense protective layer, thereby improving the cohesion, flame retardancy, lubrication and wear resistance of the epoxy resin.

[0033] In the self-lubricating flame-retardant epoxy resin component of the present invention, the silane coupling agent can be typically but not limitedly selected as 0.6 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, 1.6 parts, and 1.8 parts; the modified graphite powder can be typically but not limitedly selected as 3 parts, 4 parts, 5 parts, 6 parts, and 7 parts; the modified nano aluminum hydroxide can be typically but not limitedly selected as 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, and 29 parts; the plasticizer can be typically but not limitedly selected as 0.6 parts, 0.7 parts, 0.8 parts, and 0.9 parts; the accelerator can be typically but not limitedly selected as 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, and 0.7 parts; the diluent can be typically but not limitedly selected as 11 parts, 12 parts, 13 parts, and 14 parts.

[0034] As an optional embodiment of the self-lubricating flame-retardant epoxy resin of the present invention, the graphite powder modifier used for the modified graphite powder includes the following preparation raw materials in parts by weight: 5-30 parts of a hydrochloric acid solution with a mass fraction of 1-7%, 0.5-8 parts of sodium lauryl sulfate, 0.3-0.6 parts of yttrium nitrate hexahydrate, and 0.1-1 parts of octadecyltrichlorosilane; further, the preparation method of the modified graphite powder is as follows: sodium lauryl sulfate is added to the hydrochloric acid solution, and then yttrium nitrate hexahydrate is added, and then octadecyltrichlorosilane is added, and the mixture is stirred and mixed thoroughly to obtain a graphite powder modifier; the graphite powder is sent into the graphite powder modifier for ultrasonic treatment, and then washed with water and dried to obtain the modified graphite powder.

[0035] In the above technical scheme, the modified graphite powder is modified by a specific modification solution and ultrasonically treated, so that the modified graphite surface can be well compatible with the resin matrix, and the graphite particle size is reduced and the strength is increased, which is more conducive to the self-lubricating property of the graphite. Specifically, in the graphite powder modifier, the mass fraction of 1-7% hydrochloric acid solution is typically but not limited to 6 parts, 10 parts, 15 parts, 20 parts, 25 parts, sodium lauryl sulfate is typically but not limited to 0.6 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, yttrium nitrate hexahydrate is typically but not limited to 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, octadecyl trichlorosilane is typically but not limited to 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts.

[0036] As an optional embodiment of the self-lubricating flame-retardant epoxy resin of the present invention, the preparation method of the modified nano aluminum hydroxide is as follows:

[0037] S1: prepare a hexadecyltrimethoxysilane ethanol solution with a mass concentration of 20-40% (such as 21%, 23%, 25%, 27%, 29%, 31%, 33%, 35%, 37%, 39%);

[0038] S2: Put nano aluminum hydroxide and hexadecyltrimethoxysilane ethanol solution into a ball mill in a weight ratio of 100:0.1-5 (such as 100:0.1, 100:0.5, 100:1, 100:2, 100:3, 100:4, 100:5) and grind for 30-60 minutes. The ground powder is dried in a vacuum dryer at 60-100°C for 2-3 hours to obtain modified nano aluminum hydroxide.

[0039] In the above technical solution, the modified nano aluminum hydroxide is surface-modified with high-concentration hexadecyltrimethoxysilane and has a large number of long-chain siloxane groups, which can be well compatible with the resin matrix.

[0040] As an optional embodiment of the self-lubricating flame-retardant epoxy resin of the present invention, the preparation method of the phenolic modified epoxy resin solution is as follows:

[0041] Step (1): In a reaction vessel, phenol and NaOH solution are mixed and kept warm;

[0042] Step (2): continue to add formaldehyde solution and keep the temperature, add acrylic epoxy resin after the temperature rises and keep the temperature, then cool down, degas and discharge to obtain phenolic modified epoxy resin solution.

[0043] In the above technical scheme, further, the mass ratio of the phenol, NaOH solution, formaldehyde solution and acrylic epoxy resin is (10-20): (1-2): (10-15): (20-30), the mass concentration of the NaOH solution is 32-34%; the mass concentration of the formaldehyde solution is 35-38%.

[0044] Furthermore, in step (1), the insulation temperature is 40-60°C and the time is 20-30 minutes;

[0045] And / or, in step (2), the insulation temperature after the addition of the formaldehyde solution is 60-75°C for 30-40 minutes; and / or, the heating temperature is increased to 75-85°C, and the insulation time after the addition of the acrylic epoxy resin is 20-30 minutes; and / or, the cooling temperature is decreased to 70-75°C; and / or, the degassing time is 10-15 minutes.

[0046] As an optional embodiment of the self-lubricating flame-retardant epoxy resin of the present invention, the plasticizer includes propylene oxide, dibutyl succinate, dibenzyl benzoate, dioctyl phthalate, dibenzyl phthalate or di(2-ethylhexyl) phthalate;

[0047] and / or, the promoter comprises triethylamine, triethanolamine, BMDA, DBU, DMP-10 or pyridine;

[0048] and / or, the diluent comprises acetone, butanone or methyl propyl ketone;

[0049] And / or, the silane coupling agent is KH560, KH792, DL602 or DL171.

[0050] According to the second aspect of the present invention, a method for preparing the self-lubricating flame-retardant epoxy resin described in the first aspect comprises: sequentially adding a silane coupling agent, modified graphite powder, modified nano-aluminum hydroxide, a plasticizer, a accelerator and a diluent to a phenolic modified epoxy resin solution, and stirring to obtain a self-lubricating flame-retardant epoxy resin; further, the stirring time is 10-20 minutes.

[0051] In the present invention, the reaction vessel used in each reaction process is not particularly limited, and can be equipped with a stirrer, a condensing device and a temperature measuring device as required, such as a reaction kettle equipped with a stirrer, a condensing device and a temperature measuring device. The preparation method of the present invention is simple and feasible, stable and reliable, and can be produced under existing production processes and equipment conditions, thereby realizing industrial large-scale production, and has broad application prospects in the field of pultruded profiles.

[0052] According to a third aspect of the present invention, a self-lubricating flame-retardant epoxy resin as described in the first aspect or a self-lubricating flame-retardant epoxy resin prepared by the preparation method as described in the second aspect is used as a basalt fiber pultrusion molding matrix material.

[0053] The self-lubricating flame-retardant epoxy resin of the present invention has good self-lubricating property and can be used to form a uniform and compact flame-retardant layer (pultruded profile) in the basalt fiber pultrusion molding process. The basalt fiber and the self-lubricating flame-retardant epoxy resin play a synergistic role to achieve the flame-retardant purpose to the maximum extent.

[0054] The present invention will be further described in detail below with reference to specific embodiments and comparative examples.

[0055] Examples 1-5

[0056] A self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion and a preparation method thereof, comprising the following raw materials in parts by weight: 100 parts of phenolic modified epoxy resin solution, 0.5-2 parts of silane coupling agent, 2-8 parts of modified graphite powder, 20-30 parts of modified nano aluminum hydroxide, 0.5-1.0 parts of plasticizer, 0.2-0.8 parts of accelerator and 10-15 parts of diluent.

[0057] The preparation method of modified graphite powder is as follows: add 5 parts of sodium lauryl sulfate to 25 parts of 2% hydrochloric acid solution by mass, then add 0.5 parts of yttrium nitrate hexahydrate, and then add 0.5 parts of octadecyltrichlorosilane, stir and react fully to obtain a graphite powder modifier, send the graphite powder into the graphite powder modifier for ultrasonic treatment for 30 minutes, and after the ultrasonic treatment is completed, wash with water and dry to obtain modified graphite powder.

[0058] The preparation method of modified nano aluminum hydroxide is as follows:

[0059] S1: prepare a 30% hexadecyltrimethoxysilane ethanol solution;

[0060] S2: Add nano aluminum hydroxide and hexadecyltrimethoxysilane ethanol solution in a weight ratio of 100:3 into a ball mill and grind for 30-60 minutes. Dry the ground powder in a vacuum dryer at 60-100° C. for 2-3 hours to obtain modified nano aluminum hydroxide.

[0061] The preparation of self-lubricating flame-retardant epoxy resin includes the following steps:

[0062] B1: In a reaction kettle equipped with a stirrer, a condensing device, and a temperature measuring device, 15 parts of phenol and 1.5 parts of a 33% NaOH solution were mixed by weight, and kept warm at 40-60°C for 20-30 minutes;

[0063] B2: Continue to add 12 parts of 36% formaldehyde solution, keep warm at 60-75°C for 30-40 minutes, raise the temperature to 75-85°C, add 25 parts of acrylic epoxy resin, keep warm for 20-30 minutes; cool down to 70-75°C, degas for 10-15 minutes, cool down and discharge to obtain phenolic modified epoxy resin solution;

[0064] B3: Add silane coupling agent, modified graphite powder (self-lubricating filler), modified nano aluminum hydroxide (flame retardant filler), plasticizer, accelerator, and diluent to the phenolic modified epoxy resin solution prepared in B2, and stir for 10-20 minutes to prepare a self-lubricating flame retardant epoxy resin.

[0065] According to the above preparation process, the self-lubricating flame-retardant epoxy resins of Examples 1-5 were obtained according to the same preparation parameters, and the raw materials for each preparation are shown in Table 1 below:

[0066] Table 1 Components of self-lubricating flame-retardant epoxy resins in Examples 1-5

[0067] project Example 1 Example 2 Example 3 Example 4 Example 5 Phenolic modified epoxy resin solution / g 100 100 100 100 100 KH792 / g 0.5 1 1 1.5 2 Modified graphite powder / g 2 3 5 7 8 Modified nano aluminum hydroxide / g 20 22 24 26 28 Propylene oxide / g 0.5 0.6 0.7 0.8 0.9 Triethylamine / g 0.2 0.4 0.5 0.6 0.8 Acetone / g 10 11 12 14 15

[0068] Embodiment 6-8

[0069] The only difference from Example 3 is that the addition amounts of sodium lauryl sulfate, yttrium nitrate hexahydrate and octadecyltrichlorosilane are different when preparing the graphite powder modifier used for the modified graphite powder, and the rest of the settings are the same as those of Example 3. See Table 2 for details:

[0070] Table 2 Graphite powder modifier composition table for Examples 6-8

[0071] project Sodium lauryl sulfate / g Yttrium nitrate hexahydrate / g Octadecyltrichlorosilane / g Example 6 0.5 0.3 0.9 Example 7 3 0.4 0.7 Example 3 5 0.5 0.5 Example 8 8 0.6 0.2

[0072] Example 9

[0073] The only difference from Example 3 is that when preparing the modified nano-aluminum hydroxide, the mass concentration of the hexadecyltrimethoxysilane ethanol solution is 20%, and the other settings are the same as those in Example 3.

[0074] Example 10

[0075] The only difference from Example 3 is that, when preparing the modified nano-aluminum hydroxide, the mass concentration of the hexadecyltrimethoxysilane ethanol solution is 40%, and the other settings are the same as those in Example 3.

[0076] Comparative Example 1

[0077] The only difference from the self-lubricating flame-retardant epoxy resin in Example 3 is that it does not contain modified graphite powder, and the rest of the configurations are the same as those in Example 3.

[0078] Comparative Example 2

[0079] The only difference from the self-lubricating flame-retardant epoxy resin in Example 3 is that it does not contain modified nano aluminum hydroxide, and the rest of the configurations are the same as those in Example 3.

[0080] Comparative Example 3

[0081] The only difference from Example 3 is that when preparing the self-lubricating flame-retardant epoxy resin, graphite powder is dissolved in a 2% hydrochloric acid solution and ultrasonically treated. The rest of the settings are the same as those in Example 3.

[0082] Comparative Example 4

[0083] The only difference from Example 3 is that sodium lauryl sulfate is not added to the graphite powder modifier during the preparation of the modified graphite powder, and the rest of the settings are the same as those in Example 3.

[0084] Comparative Example 5

[0085] The only difference from Example 3 is that yttrium nitrate hexahydrate is not added to the graphite powder modifier during the preparation of the modified graphite powder, and the rest of the settings are the same as those in Example 3.

[0086] Comparative Example 6

[0087] The only difference from Example 3 is that no octadecyltrichlorosilane is added to the graphite powder modifier during the preparation of the modified graphite powder, and the rest of the settings are the same as those in Example 3.

[0088] Comparative Example 7

[0089] The only difference from Example 3 is that the preparation method of modified nano aluminum hydroxide is as follows:

[0090] S1: Prepare a 30% KH550 (3-aminopropyltriethoxysilane) ethanol solution;

[0091] S2: Add nano aluminum hydroxide and KH550 ethanol solution into a ball mill in a weight ratio of 100:3.

[0092] The rest of the settings are the same as those in Example 3.

[0093] Application and testing

[0094] The self-lubricating flame-retardant epoxy resin obtained in Examples 1-10 and Comparative Examples 1-7 was used as a basalt fiber matrix material for pultrusion molding to obtain a 5mm thick basalt fiber reinforced self-lubricating flame-retardant epoxy resin composite material layer, the surface quality of the composite material layer was intact, and the basalt fiber had a diameter of 5 to 9 microns, a length of 6 to 8 mm, and a total mass of 20%. The obtained composite material layer was randomly grouped for various performance tests, including friction coefficient determination: the friction coefficient was tested using a friction coefficient tester at a test speed of 300 mm / min. The smaller the friction coefficient, the better the lubrication performance of the composite material layer; the others were measured according to the Chinese national standard GB / T31539-2015, and the results of various performance measurements are shown in Table 3 below:

[0095] Table 3

[0096]

[0097] As can be seen from Table 3, the present invention uses modified graphite powder and modified nano-aluminum hydroxide to synergistically modify epoxy resin, giving the epoxy resin self-lubricating and flame retardant properties, so that it has the characteristics of low friction coefficient, good flame retardancy, high strength, good toughness, low shrinkage, etc., and the preparation process is simple and easy to industrialize, and has broad application prospects in the field of basalt fiber pultrusion profiles.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A self-lubricating flame-retardant epoxy resin for basalt fiber pultrusion molding, characterized in that: The preparation method comprises the following raw materials in parts by weight: 100 parts of phenolic modified epoxy resin solution, 0.5-2 parts of silane coupling agent, 2-8 parts of modified graphite powder, 20-30 parts of modified nano aluminum hydroxide, 0.5-1.0 parts of plasticizer, 0.2-0.8 parts of accelerator and 10-15 parts of diluent.

2. The self-lubricating flame-retardant epoxy resin according to claim 1, characterized in that: The graphite powder modifier used in the modified graphite powder comprises the following raw materials in parts by mass: 5-30 parts of hydrochloric acid solution with a mass fraction of 1-7%, 0.5-8 parts of sodium lauryl sulfate, 0.3-0.6 parts of yttrium nitrate hexahydrate, and 0.1-1 parts of octadecyltrichlorosilane.

3. The self-lubricating flame-retardant epoxy resin according to claim 1, characterized in that: The modified graphite powder preparation method is as follows: adding sodium lauryl sulfate to a hydrochloric acid solution, then adding yttrium nitrate hexahydrate, and then adding octadecyltrichlorosilane, stirring and mixing thoroughly to obtain a graphite powder modifier; sending the graphite powder into the graphite powder modifier for ultrasonic treatment, and then washing and drying to obtain the modified graphite powder.

4. The self-lubricating flame-retardant epoxy resin according to claim 1, characterized in that: The modified nano aluminum hydroxide preparation method is as follows: S1: preparing a hexadecyltrimethoxysilane ethanol solution with a mass concentration of 20-40%; S2: Add nano aluminum hydroxide and hexadecyltrimethoxysilane ethanol solution in a weight ratio of 100:0.1-5 into a ball mill and grind for 30-60 minutes. Dry the ground powder in a vacuum dryer at 60-100° C. for 2-3 hours to obtain modified nano aluminum hydroxide.

5. The self-lubricating flame-retardant epoxy resin according to claim 1, characterized in that: The preparation method of the phenolic modified epoxy resin solution is as follows: Step (1): In a reaction vessel, phenol and NaOH solution are mixed and kept warm; Step (2): continue to add formaldehyde solution and keep the temperature, add acrylic epoxy resin after the temperature rises and keep the temperature, then cool down, degas and discharge to obtain phenolic modified epoxy resin solution.

6. The self-lubricating flame-retardant epoxy resin according to claim 5, characterized in that: The mass ratio of the phenol, NaOH solution, formaldehyde solution and acrylic epoxy resin is (10-20): (1-2): (10-15): (20-30), the mass concentration of the NaOH solution is 32-34%; the mass concentration of the formaldehyde solution is 35-38%.

7. The self-lubricating flame-retardant epoxy resin according to claim 5, characterized in that: In step (1), the insulation temperature is 40-60°C and the time is 20-30 minutes; And / or, in step (2), the insulation temperature after the addition of the formaldehyde solution is 60-75°C for 30-40 minutes; and / or, the heating temperature is increased to 75-85°C, and the insulation time after the addition of the acrylic epoxy resin is 20-30 minutes; and / or, the cooling temperature is decreased to 70-75°C; and / or, the degassing time is 10-15 minutes.

8. The self-lubricating flame-retardant epoxy resin according to claim 1, characterized in that: The plasticizer includes propylene oxide, dibutyl succinate, dibenzyl benzoate, dioctyl phthalate, dibenzyl phthalate or di(2-ethylhexyl) phthalate; and / or, the promoter comprises triethylamine, triethanolamine, BMDA, DBU, DMP-10 or pyridine; and / or, the diluent comprises acetone, butanone or methyl propyl ketone; And / or, the silane coupling agent is KH560, KH792, DL602 or DL171.

9. A method for preparing the self-lubricating flame-retardant epoxy resin according to any one of claims 1 to 8, characterized in that: include: Adding silane coupling agent, modified graphite powder, modified nano aluminum hydroxide, plasticizer, accelerator and diluent to the phenolic modified epoxy resin solution in sequence, stirring to obtain a self-lubricating flame-retardant epoxy resin; Furthermore, the stirring time is 10-20 min.

10. Use of the self-lubricating flame-retardant epoxy resin according to any one of claims 1 to 8 or the self-lubricating flame-retardant epoxy resin prepared by the preparation method according to claim 9 as a matrix material for basalt fiber pultrusion molding.

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