CN106811824B

CN106811824B - Modified phenolic resin fiber and preparation method and application thereof

Info

Publication number: CN106811824B
Application number: CN201611179326.0A
Authority: CN
Inventors: 张金柱; 任方华; 盛杰; 张安; 张小鸽; 刘顶
Original assignee: Shandong Shengquan New Material Co Ltd
Current assignee: Shandong Shengquan New Material Co Ltd
Priority date: 2016-12-19
Filing date: 2016-12-19
Publication date: 2020-05-05
Anticipated expiration: 2036-12-19
Also published as: CN106811824A

Abstract

The invention relates to a preparation method of modified phenolic resin fibers, which comprises the following steps: (1) adding a polymer to a prepolymer of a phenolic resin to obtain a polymer-prepolymer solution; (2) adding a graphene substance into the polymer-prepolymer solution, carrying out polymerization reaction on the thermoplastic phenolic resin to obtain a reaction solution, and purifying to obtain a modified phenolic resin; (3) and (3) spinning the modified phenolic resin obtained in the step (2) into phenolic fiber precursor, and curing and crosslinking to obtain the modified phenolic resin fiber. The invention realizes the uniform dispersion of the graphene, solves the problems of easy agglomeration and poor dispersibility when the graphene is simply added, and improves the strength, toughness, electrical properties and the like of the phenolic fiber.

Description

Modified phenolic resin fiber and preparation method and application thereof

Technical Field

The invention belongs to the field of phenolic resin modification, and relates to a modified phenolic resin fiber and a preparation method thereof.

Background

The phenolic fiber is a fiber with a three-dimensional reticular structure obtained by spinning and curing phenolic resin, and is firstly developed and succeeded by American carborundum company in 1968 [ J.Economy, R.A.Clark.fibers from Nocolacs [ P ]. USPat.3650102,1968 ]. The phenolic fiber has the characteristics of outstanding high temperature resistance, flame resistance, corrosion resistance, melting resistance and the like, has high extreme oxygen index and has self-extinguishing property; the shrinkage rate is small during combustion, and the smoke is less; based on the excellent performances, the research on the phenolic fibers is highly concerned, and the further research and development of the phenolic fibers are driven; the phenolic fiber spinning process generally takes thermoplastic phenolic resin as a raw material, obtains protofilaments through melt spinning, and is formed by cross-linking and curing through formaldehyde, hydrochloric acid and other solutions; meanwhile, because the residual carbon content of the phenolic fiber is high, the escape of harmful gas is less, the phenolic fiber can be further activated into carbon fiber, and the phenolic fiber can be widely applied to various fields of heat resistance, adsorption and the like. With the development of industries such as aerospace, national defense and the like, the application field of the phenolic fiber is continuously expanded, and the pure phenolic fiber cannot meet the increasingly expanded market demand. The preparation performance is excellent, the application field is wide, and especially the high-performance phenolic fiber with more excellent heat resistance, strength and toughness becomes the key point of the field.

The structure of the phenolic fiber can be exemplarily expressed as:

as can be seen from the above formula, because the benzene ring density is high, and only methylene is connected between two adjacent benzene rings, the phenolic fiber is very brittle, so that the phenolic fiber has low toughness and small elongation at break, phenolic hydroxyl is easy to oxidize, the heat resistance, oxidation resistance and alkali resistance of the phenolic fiber are influenced to a certain extent, and the performance of the product is reduced due to the defects, and the use is limited to a certain extent. Therefore, the modification of the phenolic fiber is carried out, the structural defects of the phenolic fiber are reduced, and the method is a fundamental method for improving the high strength, the toughness and the heat resistance of the phenolic fiber.

There is a need in the art to develop a phenolic fiber having excellent heat resistance, high strength and high toughness.

Disclosure of Invention

Aiming at the defects of poor mechanical property, low mechanical strength, poor heat resistance and the like of the phenolic fiber in the prior art, the invention aims to provide a preparation method of a modified phenolic resin fiber, which comprises the following steps:

(1) adding a polymer to a prepolymer of a phenolic resin to obtain a polymer-prepolymer solution;

(2) adding a graphene substance into the polymer-prepolymer solution, carrying out polymerization reaction on the thermoplastic phenolic resin to obtain a reaction solution, and purifying to obtain a modified phenolic resin;

(3) and (3) spinning the modified phenolic resin obtained in the step (2) into phenolic fiber precursor, and curing and crosslinking to obtain the modified phenolic resin fiber.

According to the invention, the polymer is added into the phenolic resin prepolymer, the polymer and the phenolic resin prepolymer are uniformly dispersed, and after the graphene substance is added, the graphene substance can generate weak bonds and actions (such as Van der Waals force) with the polymer, so that the agglomeration of the graphene substance can be effectively prevented, and the uniform dispersion of the graphene substance in the phenolic resin is realized.

In addition, in the preparation process of the phenolic resin, the polymer is added, so that the polymer added in the subsequent spinning step for improving the spinnability can be omitted, and the steps are simplified.

The polymer of the present invention is not particularly limited, and any polymer capable of increasing spinnability may be used herein.

Preferably, the molar ratio of the prepolymer of the phenolic resin to the polymer is 1: 0.005-0.1, such as 1:0.006, 1:0.008, 1:0.01, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, etc., based on the aldehyde substance.

In the polymerization of the phenol resin thermoplastic by mixing the graphene-based material with the polymer-prepolymer, the mass of the graphene-based material is 0.01 to 15wt%, for example, 0.05 wt%, 0.1 wt%, 0.6 wt%, 0.9 wt%, 2wt%, 3.5 wt%, 4.2 wt%, 4.6 wt%, 5.8 wt%, 7 wt%, 8 wt%, 9 wt%, 10wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, etc., preferably 0.01 to 10wt%, more preferably 0.01 to 5wt%, particularly preferably 0.01 to 2wt%, most preferably 0.1 to 1wt% of the phenol resin.

The graphene-based substance comprises any 1 or mixture of at least 2 of graphene, biomass graphene, graphene oxide and graphene derivatives, and the graphene derivatives comprise element-doped graphene.

The graphene oxide is used as a precursor or a derivative of graphene, the performance of the graphene oxide is not inferior to that of graphene, and the surface of the graphene oxide contains rich oxygen-containing functional groups, so that the active sites can be improved for the further chemical reaction of the graphene oxide; the graphene oxide can be subjected to co-curing reaction with resin or form a partial interpenetrating network structure embedded polymer intermediate group, has good compatibility, does not have the condition of phase separation, increases the spinnability and mechanical property of the phenolic fiber, and improves the electrical property of the phenolic fiber.

Preferably, the graphene derivative comprises any 1 or combination of at least 2 of element-doped graphene or functionalized graphene species.

Preferably, the element-doped graphene includes any 1 or a combination of at least 2 of metal-doped graphene or non-metal element-doped graphene.

The metal-doped metal element comprises any 1 or at least 2 of potassium, sodium, gold, silver, iron, copper, nickel, chromium, titanium, vanadium or cobalt.

The nonmetal elements of the nonmetal element doped graphene comprise any 1 or at least 2 of nitrogen, phosphorus, silicon, boron or oxygen.

Preferably, the non-metal element doped graphene includes any 1 or a combination of at least 2 of nitrogen-doped graphene, phosphorus-doped graphene, or sulfur-doped graphene.

Preferably, the functionalized graphene comprises graphene grafted with a functional group.

Preferably, the functionalized graphene comprises graphene grafted with any 1 or a combination of at least 2 of hydroxyl, carboxyl or amino groups.

Preferably, the hydroxy group comprises-R₁-OH, said R₁Including hydrocarbyl groups, preferably including any 1 or combination of at least 2 of methyl, ethyl, propyl, butyl, pentyl, hexyl, ethenyl, propenyl groups.

Preferably, the carboxyl group comprises-R₂-COOH, said R₂Including hydrocarbyl groups, preferably including any 1 or combination of at least 2 of methyl, ethyl, propyl, butyl, pentyl, hexyl groups.

Preferably, the carboxyl group comprises R₃-NH₃Said R is₃Including an alkane group, preferably including any 1 or a combination of at least 2 of methyl, ethyl, propyl, butyl, pentyl, hexyl.

Preferably, the graphene-based material of step (2) is added in the form of a dispersion.

Preferably, the solvent of the dispersion comprises any 1 or a combination of at least 2 of ethanol, water, ethylene glycol, DMF, NMP or acetone; ethanol or water is preferred.

The solvent of the graphene-based material solution may be selected from various solvents as long as the graphene-based material has high solubility and does not have an excessive adverse effect on the polymerization reaction, and for example, the solvent is one or more selected from water, ethanol, ethylene glycol, DMF, NMP and acetone, and ethanol or water is preferred.

Preferably, the concentration of the graphene-like substance in the dispersion liquid is 15mg/g or less, preferably 1 to 10mg/g, and more preferably 3 to 5 mg/g.

Preferably, the dispersion of the graphene-based material is added to the polymer-prepolymer solution in a dropwise manner; the dropping rate is preferably 0.5 to 2mL/min, for example, 0.6mL/min, 0.9mL/min, 1.3mL/min, 1.6mL/min, 1.9mL/min, or the like.

Preferably, the polymer in step (1) comprises any 1 or combination of at least 2 of rubber, polyacrylamide, polyacrylic acid, polyvinylpyrrolidone, polyvinyl alcohol or polyethylene glycol, preferably polyvinyl alcohol.

Illustratively, the combination of polymers includes a combination of polyacrylamide and polyacrylic acid, a combination of polyvinylpyrrolidone and polyethylene glycol, a combination of polyvinyl alcohol and polyacrylic acid, and the like.

The rubber is one or more of nitrile rubber, styrene butadiene rubber and natural rubber.

Preferably, the prepolymer of the phenolic resin is obtained by pre-polymerization of the polymerized monomers of the phenolic resin.

Preferably, the phenol of the phenolic resin polymeric monomer comprises phenol and derivatives thereof, preferably any 1 or a combination of at least 2 of phenol, cresol, xylenol, naphthol, alkyl substituted phenol, alkyl substituted naphthol, bisphenol a or bisphenol F.

Preferably, the aldehyde of the phenolic resin polymeric monomer comprises formaldehyde and derivatives thereof, preferably a combination of any 1 or at least 2 of formaldehyde, acetaldehyde or furfural.

Preferably, the prepolymerization reaction comprises the following steps: mixing the polymerization monomer of the phenolic resin with a catalyst, and reacting for 0.5-4 h, such as 0.6h, 0.8h, 1h, 2h, 3h, 4h and the like at 60-80 ℃, such as 62 ℃, 68 ℃, 73 ℃, 78 ℃ and the like.

In the prepolymerization reaction, the molar ratio of the phenol monomer in terms of hydroxyl group, the aldehyde monomer in terms of aldehyde group and the catalyst is preferably 1 (0.7-1) to (0.005-0.05), such as 1:0.8:0.008, 1:0.9:0.01, 1:0.8:0.02, 1:0.9:0.03, 1:0.8:0.04, etc.

Preferably, the catalyst comprises an acidic catalyst.

Preferably, the acidic catalyst comprises any 1 or a combination of at least 2 of hydrochloric acid, oxalic acid, acetic acid or sulfuric acid.

Preferably, the reaction temperature of the polymerization reaction of the thermoplastic phenolic resin is 80-95 ℃, such as 82 ℃, 83 ℃, 85 ℃, 88 ℃ and the like, and the reaction time is 0.5-4 h, such as 0.6h, 0.8h, 1h, 2h, 3h, 4h and the like.

As one of the preferable technical proposal, the preparation method of the modified phenolic resin fiber comprises the following steps:

(2') dispersing a graphene substance in a solvent to obtain a graphene substance dispersion liquid;

(2) dropwise adding the graphene substance dispersion liquid obtained in the step (2') into the polymer-prepolymer solution obtained in the step (1), carrying out polymerization reaction on the thermoplastic phenolic resin to obtain a reaction liquid, and purifying to obtain phenolic resin;

(3) and (3) preparing the phenolic resin into phenolic fiber protofilaments through melt spinning, and curing and crosslinking to obtain the modified phenolic resin fibers.

The second purpose of the invention is to provide a modified phenolic resin fiber, which is obtained by the preparation method of the modified phenolic resin fiber.

The third object of the present invention is to provide a use of the modified phenolic resin fiber described in the second object as any 1 or a combination of at least 2 of a reinforcing material, a flame-retardant and heat-insulating material, a thermal insulating material, a cushioning material, a phenolic-based carbon fiber, and an electrode material.

The invention also provides an electrode composite material which is obtained by carbonizing the phenolic resin fiber of the second purpose.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, graphene and phenolic resin are compounded to obtain modified phenolic resin, and the modified phenolic fiber is obtained after spinning. According to the invention, the phenolic resin prepolymer and the polymer are uniformly mixed, the graphene is added, and the graphene is connected with the polymer through the weak bond, so that the graphene is uniformly dispersed, the problems of easy agglomeration and poor dispersibility caused by the simple addition of the graphene are solved, and the strength, toughness, electrical properties and the like of the phenolic fiber are improved.

Particularly, when the graphene substance is graphene oxide and the polymer is polyvinylpyrrolidone PVA, the PVA is mixed with the phenolic resin prepolymer, the graphene oxide acts with the PVA through the oxygen-containing group, the graphene oxide is uniformly dispersed, the toughness of the phenolic resin is improved, the tensile strength is 153-330 MPa, the elongation is 6.2-20%, and the effects of strength and heat resistance are achieved.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.

It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

In the following examples, the ratio of phenol, aldehyde and catalyst is the molar ratio of the phenol monomer in terms of hydroxyl group, the aldehyde monomer in terms of aldehyde group and the catalyst.

The graphene used in all of the following examples and comparative examples was commercially available HX-G graphene;

the graphene oxide is obtained by ultrasonically dispersing commercially available SE2430 graphite oxide.

The carboxylated graphene oxide, the biomass graphene and the oxidized biomass graphene can be prepared by the following methods, but are not limited to the following methods, and can also be prepared by the methods of graphene and graphene oxide in the prior art, or can also be directly prepared by the commercially available graphene and graphene oxide.

The commercially available biomass graphene is prepared from biomass graphene produced by the Jinan Shengquan group or prepared by the preparation example 2.

Preparation example 1: carboxylated graphene oxide

Ultrasonically dispersing 100mg of graphite oxide in 100ml of water to obtain a 1mg/ml graphene oxide aqueous solution, then adding 6g of sodium hydroxide and 5g of chloroacetic acid, ultrasonically treating for 3h to convert epoxy groups and hydroxyl groups on the surface of the graphene oxide into carboxyl groups, filtering while hot to remove impurities, and then carrying out vacuum drying at 65 ℃ to obtain the carboxylated graphene oxide.

Preparation example 2: biomass graphene

Firstly, preparing cellulose:

(1) crushing wheat straws, pretreating, cooking the treated wheat straws by using organic acid liquor of formic acid and acetic acid with total acid concentration of 80 wt%, wherein the mass ratio of acetic acid to formic acid in the organic acid liquor is 1:12, adding hydrogen peroxide (H2O2) accounting for 1wt% of the raw materials of the wheat straws as a catalyst before adding the raw materials, controlling the reaction temperature at 120 ℃, reacting for 30min, and carrying out first solid-liquid separation on the obtained reaction liquid, wherein the solid-liquid mass ratio is 1: 10;

(2) adding organic acid solution of formic acid and acetic acid with total acid concentration of 75 wt% into solid obtained by the first solid-liquid separation for acid washing, wherein hydrogen peroxide (H) accounting for 8 wt% of the wheat straw raw material is added into the organic acid solution with total acid concentration of 75 wt%₂O₂) As a catalyst, the mass ratio of acetic acid to formic acid is 1:12, the temperature is controlled to be 90 ℃, the washing time is 1h, the solid-liquid mass ratio is 1:9, and the reaction liquid is subjected to secondary solid-liquid separation;

(3) collecting the liquid obtained by the first solid-liquid separation and the second solid-liquid separation, evaporating at 120 ℃ and 301kPa until the liquid is evaporated to dryness, condensing and refluxing the obtained formic acid and acetic acid vapor to the reaction kettle in the step (1) to be used as cooking liquid for the cooking in the step (1);

(4) collecting the solid obtained by the second solid-liquid separation, washing with water, controlling the washing temperature to be 80 ℃, and the concentration of the washed pulp to be 6 wt%, and carrying out the third solid-liquid separation on the obtained washed pulp;

(5) collecting liquid obtained by the third solid-liquid separation, and performing water-acid rectification to obtain mixed acid liquid which is reused in the reaction kettle in the step (1) and used as cooking liquid for cooking in the step (1), and reusing the obtained water as washing water in the step (5);

(6) and collecting the solid obtained by the third solid-liquid separation and screening to obtain the required fine pulp cellulose.

Step two, preparing graphene by taking the cellulose prepared above as a raw material:

(1) mixing cellulose and ferrous chloride according to the mass ratio of 1:1, stirring at 150 ℃ for catalytic treatment for 4 hours, and drying until the moisture content of a precursor is 10wt% to obtain the precursor;

(2)N₂in the atmosphere, heating the precursor to 170 ℃ at the speed of 3 ℃/min, preserving heat for 2h, then, programming to 400 ℃, preserving heat for 3h, then, heating to 1200 ℃, and preserving heat for 3h to obtain a crude product; the temperature rising rate of the temperature programming is 15 ℃/min;

(3) and (3) washing the crude product with 10% sodium hydroxide solution and 4 wt% hydrochloric acid at 55-65 ℃, and washing with water to obtain the biomass graphene.

Preparation example 3: oxidized biomass graphene

Due to the existence of a porous structure, the sheet layer of the biomass graphene is in an open state relative to graphite, so that the oxidation condition is weaker than that of graphite. The specific implementation process is as follows:

mixing 2g of biomass graphene and 30mL of concentrated sulfuric acid in a reactor, stirring for 10min under the ice-water bath condition, gradually adding 7g of potassium permanganate, controlling the temperature to be not higher than 35 ℃, continuing stirring for 2h under the normal temperature condition after the potassium permanganate is added, heating to 40 ℃, reacting for 30min, adding 30 wt% hydrogen peroxide of about 5mL in volume, changing the color of the solution into golden yellow, adding 150mL of distilled water for diluting, filtering the reaction solution while hot, respectively washing with 4mL of dilute hydrochloric acid with the mass fraction of 10% and 100mL of deionized water for 2-3 times, centrifuging, and spray-drying slurry to obtain oxidized biomass graphene.

Example 1

The preparation method of the modified phenolic resin fiber comprises the following steps:

(1) mixing phenol: formaldehyde: adding oxalic acid into a four-neck flask according to the molar ratio of 1:0.8:0.05, heating at 70 ℃, stirring and refluxing for 2 hours to obtain a prepolymer of the phenolic resin; adding PVA (the molar ratio of the prepolymer of the phenolic resin to the PVA polymer is 1:0.005 in terms of aldehyde substances) into the phenolic resin prepolymer to obtain a polymer-prepolymer solution;

(2) dispersing graphene oxide in water to obtain a graphene substance dispersion liquid; the concentration of the graphene substance dispersion liquid is 10 mg/g;

(3) polymerization reaction: dropwise adding the graphene substance dispersion liquid obtained in the step (2) into the polymer-prepolymer solution in the step (1) at 85 ℃, heating, stirring and refluxing for 3 hours, stopping stirring, adding ethanol, and removing free phenol through steam distillation for purification to obtain phenolic resin;

(4) carrying out melt spinning on the phenolic resin at 130 ℃ and 0.2MPa, drafting to obtain nascent phenolic fibers, putting the nascent phenolic fibers into a solidification bath for solidification, wherein the content of formaldehyde in the solidification bath is 10%, the content of hydrochloric acid is 15%, the content of water is 75%, the temperature is 80-100 ℃, the heating rate is 10-20 ℃/h, then keeping the temperature constant, solidifying for 1-2 h, washing with water, and drying to obtain the graphene modified phenolic fibers.

Wherein the addition amount of the graphene oxide is 0.5 percent of that of the phenolic resin product.

Example 2

The difference from example 1 is that: the substituted graphene oxide is carboxylated graphene oxide.

Example 3

The difference from example 1 is that the graphene oxide is replaced by graphene.

Example 4

The difference from example 1 is that the graphene oxide was replaced with graphene oxide as the biomass.

Example 5

The difference from example 1 is that the replacement graphene oxide is oxidized biomass graphene.

Examples 6 to 9

The difference from the example 1 is that the addition amount of the graphene oxide is 0.01 wt%, 1wt%, 10wt%, 15wt% of the phenolic resin product.

Examples 10 to 12

The difference from example 1 is that the solubility of the added graphene oxide solution is different, namely 1mg/g, 5mg/g and 15 mg/g.

Examples 13 to 15

The difference from example 1 is that the solvents of the graphene oxide solution are different, namely ethanol, DMF and acetone.

Examples 16 to 21

The difference from example 14 (solvent is DMF) is that polyvinyl alcohol was replaced with polyvinylpyrrolidone, polyethylene glycol, nitrile rubber, styrene-butadiene rubber, polyurethane, natural rubber, respectively.

Example 22

The difference from example 1 is that the kinds of phenol and aldehyde are different,

mixing "phenol: formaldehyde: oxalic acid was replaced by "phenol: and (3) furfural: oxalic acid was in a ratio of 1:0.8:0.05 ".

Example 23

Compared with the example 1, the proportion of the phenolic resin and the PVA is different,

PVA (the molar ratio of the prepolymer of the phenolic resin to the polymer PVA is 1:0.01 calculated by aldehyde substances) is added into the phenolic resin prepolymer.

Example 24

PVA (the molar ratio of the prepolymer of the phenolic resin to the polymer PVA is 1:0.1 based on aldehydes) is added into the phenolic resin prepolymer.

Comparative example 1

The difference from example 1 is that graphene and polyvinyl alcohol are added to the phenolic resin in one pot at the start of the reaction.

The method specifically comprises the following steps:

mixing phenol: formaldehyde: adding oxalic acid into a four-neck round-bottom flask provided with a stirrer, a thermometer and a condenser according to a molar ratio of 1:0.8:0.05, uniformly stirring, then adding polyvinyl alcohol and a graphene oxide solution, heating and stirring at 70 ℃ for 2h, heating to 85 ℃, continuing heating and stirring for 3h, stopping stirring, adding ethanol, removing free phenol through steam distillation, and purifying to obtain phenolic resin;

carrying out melt spinning on the phenolic resin at 130 ℃ and 0.2MPa, drafting to obtain nascent phenolic fibers, putting the nascent phenolic fibers into a solidification bath for solidification, wherein the content of formaldehyde in the solidification bath is 10%, the content of hydrochloric acid is 15%, the content of water is 75%, the temperature is 80-100 ℃, the heating rate is 10-20 ℃/h, then keeping the temperature constant, solidifying for 1-2 h, washing with water, and drying to obtain the graphene modified phenolic fibers.

Wherein the concentration of the graphene oxide is 10 mg/g;

the addition of the graphene oxide is 0.5 percent of the phenolic resin product.

Comparative example 2

The difference from example 1 is that no PVA was added.

Comparative example 3

The difference from comparative example 1 is that PVA and graphene oxide were not added.

Comparative example 4

The difference from comparative example 1 is that no graphene oxide was added.

The process conditions of all the graphene modified phenolic fibers are shown in table 1 below.

TABLE 1 Process conditions for the examples and comparative examples

In table 1, the content of the polymer is the molar ratio of the polymer to the phenolic resin.

The mechanical property data of the fibers prepared in the above examples 1 to 24 and comparative examples 1 to 3 were determined according to GB/T14344-.

TABLE 2

As can be seen from the test results of example 1 and comparative example 1 in table 2, after the phenolic resin prepolymer and the polymer are uniformly mixed, graphene is added, and the graphene is connected with the polymer through a weak bond, so that the graphene is uniformly dispersed, the problems that the graphene is easily agglomerated and has poor dispersibility when being simply added are solved, and the strength, toughness and the like of the phenolic fiber are improved; from the results of example 1 and comparative example 2, it can be seen that the addition of PVA enables graphene oxide to be better dispersed in resin without agglomeration, thereby further improving the strength of the fiber; from the results of example 1 and comparative example 3, it can be seen that the toughness as well as the strength of the resin can be greatly improved by the addition of polyvinyl alcohol and graphene oxide. From the results of examples 1, 16, 17, 18, 19, 20, 21 and 22, it can be seen that polyvinyl alcohol is effective, rubber is relatively poor, and others are almost as poor as polyvinyl alcohol.

The phenolic resin fibers obtained in the examples 1-24 and the comparative examples 1-3 are placed in a tubular resistance furnace, heated to 800 ℃ at a heating rate of 3 ℃/min under the protection of nitrogen, and kept at the constant temperature for 3 hours to obtain an electrode material, and the electrode material is applied to the preparation of electrodes.

Preparing an electrode: mixing the electrode material, the conductive carbon black and the binder according to a mass ratio of 85:10:5, then carrying out ultra-high speed shearing mixing at a speed of 5000rpm, then forming a film with uniform thickness by vertically rolling and horizontally rolling at 80MPa, and placing the film at 100 ℃ for 24 hours. And cutting the dried film into electrode slices of 1 multiplied by 1cm, weighing, placing between two pieces of foamed nickel, leading out by nickel slices, and compacting by using a tablet press under 8MPa to obtain the electrode to be measured.

And (3) electrochemical performance testing:

and (3) placing the electrode to be tested in 6M KOH solution, soaking for 24h, then accessing to an electrochemical workstation, and testing by adopting a three-electrode system. The specific capacitance at 0.1A/g is shown in Table 3 below.

TABLE 3

The applicant states that the present invention is illustrated by the above examples of the process of the present invention, but the present invention is not limited to the above process steps, i.e. it is not meant that the present invention must rely on the above process steps to be carried out. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.

Claims

1. A method for preparing modified phenolic resin fibers, which is characterized by comprising the following steps:

(3) spinning the modified phenolic resin obtained in the step (2) into phenolic fiber precursor, and curing and crosslinking to obtain modified phenolic resin fibers;

adding the graphene substances in the step (2) in the form of dispersion liquid;

the solvent of the dispersion comprises any 1 of ethanol, water or DMF;

the concentration of the graphene-like substances in the dispersion liquid is 10-15 mg/g.

2. The preparation method according to claim 1, wherein the molar ratio of the prepolymer of the phenolic resin to the polymer is 1: 0.005-0.1 based on the aldehyde substance;

in the process of mixing the graphene substance and the polymer-prepolymer for polymerization reaction of the thermoplastic phenolic resin, the mass of the graphene substance is 0.01-15 wt% of that of the phenolic resin;

3. The method according to claim 2, wherein the graphene-based material is 0.01 to 10wt% based on the phenolic resin.

4. The method according to claim 3, wherein the graphene-based material is 0.01 to 5wt% based on the phenolic resin.

5. The method according to claim 4, wherein the graphene-based material is 0.01 to 2wt% based on the phenolic resin.

6. The method according to claim 5, wherein the graphene-based material is 0.1 to 1wt% based on the phenolic resin.

7. The method of claim 2, wherein the graphene derivative comprises any 1 or a combination of at least 2 of element-doped graphene or functionalized graphene.

8. The method of claim 7, wherein the element-doped graphene comprises any 1 or a combination of at least 2 of metal-doped graphene or non-metal element-doped graphene;

the metal-doped metal element comprises any 1 or at least 2 of potassium, sodium, gold, silver, iron, copper, nickel, chromium, titanium, vanadium or cobalt;

9. The method of claim 8, wherein the non-metallic element doped graphene comprises any 1 or a combination of at least 2 of nitrogen doped graphene, phosphorus doped graphene, or sulfur doped graphene.

10. The method of claim 7, wherein the functionalized graphene is selected from graphene grafted with any 1 or a combination of at least 2 of hydroxyl, carboxyl, or amino groups.

11. The method of claim 10, wherein the hydroxy group is-R₁-OH, said R₁Selected from hydrocarbyl groups.

12. The method according to claim 10, wherein the carboxyl group is-R₂-COOH, said R₂Selected from hydrocarbyl groups.

13. The method of claim 10, wherein the amino group is-R₃-NH₂Said R is₃Selected from alkyl groups.

14. The method of claim 1, wherein the solvent of the dispersion comprises ethanol or water.

15. The production method according to claim 1, wherein the dispersion of the graphene-based substance is added to the polymer-prepolymer solution in a dropwise manner; the dropping rate is preferably 0.5 to 2 mL/min.

16. The method of claim 1, wherein the polymer of step (1) comprises any 1 or a combination of at least 2 of rubber, polyacrylamide, polyacrylic acid, polyvinylpyrrolidone, polyvinyl alcohol, or polyethylene glycol;

17. The method of claim 16, wherein the polymer of step (1) is polyvinyl alcohol.

18. The method according to claim 1, wherein the prepolymer of the phenolic resin is obtained by prepolymerization of a polymerizable monomer of the phenolic resin.

19. The method of claim 18, wherein the phenol of the phenolic resin polymerizing monomer comprises phenol and derivatives thereof.

20. The method of claim 18, wherein the phenol of the phenolic resin polymerizing monomer comprises any 1 or a combination of at least 2 of phenol, naphthol, alkyl substituted phenol, alkyl substituted naphthol, bisphenol a, or bisphenol F.

21. The method of claim 18, wherein the phenol of the phenolic resin polymerizing monomer includes cresol and/or xylenol.

22. The method of claim 18, wherein the aldehyde of the phenolic resin polymerizing monomer comprises formaldehyde and derivatives thereof.

23. The method of claim 18, wherein the aldehyde of the phenolic resin polymeric monomer comprises any 1 or a combination of at least 2 of formaldehyde, acetaldehyde, or furfural.

24. The method of claim 18, wherein the prepolymerization comprises the steps of: mixing a polymerization monomer of the phenolic resin with a catalyst, and reacting for 0.5-4 h at the temperature of 60-80 ℃.

25. The method according to claim 24, wherein the molar ratio of the phenol monomer in terms of hydroxyl groups, the aldehyde monomer in terms of aldehyde groups, and the catalyst in the prepolymerization is 1 (0.7-1) to (0.005-0.05).

26. The method of claim 24, wherein the catalyst comprises an acidic catalyst.

27. The method of claim 26, wherein the acidic catalyst comprises any 1 or a combination of at least 2 of hydrochloric acid, oxalic acid, acetic acid, or sulfuric acid.

28. The preparation method according to claim 1, wherein the reaction temperature of the polymerization reaction of the thermoplastic phenolic resin is 80-95 ℃ and the reaction time is 0.5-4 h.

29. The method of any one of claims 1 to 28, comprising the steps of:

30. A modified phenolic resin fiber obtained by the method for producing a modified phenolic resin fiber according to any one of claims 1 to 29.

31. Use of the modified phenolic resin fiber of claim 30 as any 1 or combination of at least 2 of reinforcement, flame retardant and thermal insulation, cushioning, phenolic based carbon fiber, electrode material.

32. An electrode composite material, characterized in that it is obtained by carbonizing the phenolic resin fiber of claim 30.