Cellulose nanocrystal/MXene self-assembled flame-retardant antistatic coating and application thereof to glass fiber reinforced plastics

文档序号:122681 发布日期:2021-10-22 浏览:24次 中文

阅读说明:本技术 一种纤维素纳米晶体/MXene自组装阻燃抗静电涂层及在玻璃钢上的应用 (Cellulose nanocrystal/MXene self-assembled flame-retardant antistatic coating and application thereof to glass fiber reinforced plastics ) 是由 付少海 王冬 毛彦云 于 2021-07-14 设计创作,主要内容包括:本发明公开了一种纤维素纳米晶体/MXene自组装阻燃抗静电涂层及在玻璃钢上的应用,属于无卤阻燃领域。本发明利用含磷酸掺杂含氮聚合物包覆纤维素纳米晶体,多酚辅助剥离的MXene,通过自组装,获得阻燃抗静电涂层。其制备方法简单可控,涂层构筑速度快;涂层组份绿色环保。所得阻燃涂层具备磷、氮协同阻燃和纳米阻燃作用,同时赋予基材导电性,攻克了玻璃钢易燃和易产生静电等难题,在轨道交通、船舰、航空航天等领域具有很好的应用前景。(The invention discloses a cellulose nanocrystal/MXene self-assembled flame-retardant antistatic coating and application thereof to glass fiber reinforced plastics, and belongs to the field of halogen-free flame retardance. The invention utilizes phosphoric acid-containing doped nitrogen-containing polymer to coat cellulose nanocrystal and MXene stripped by polyphenol in an auxiliary way to obtain the flame-retardant antistatic coating through self-assembly. The preparation method is simple and controllable, and the coating construction speed is high; the coating components are green and environment-friendly. The obtained flame-retardant coating has the synergistic flame-retardant and nano-flame-retardant effects of phosphorus and nitrogen, simultaneously endows the substrate with conductivity, overcomes the difficult problems of flammability, easy generation of static electricity and the like of the glass fiber reinforced plastics, and has good application prospect in the fields of rail transit, ships, aerospace and the like.)

1. A method for preparing a cellulose nanocrystal/MXene self-assembled flame-retardant antistatic coating is characterized by comprising the following steps:

(1) preparing a cellulose nanocrystal suspension by taking a cellulose nanocrystal as a template, phosphoric acid as doping acid and a nitrogen-containing compound as a monomer, and carrying out in-situ oxidative polymerization in an aqueous solution to coat the cellulose nanocrystal;

(2) selective etching of Ti with hydrochloric acid and lithium fluoride3AlC2 MXene,Separating and collecting the solid to obtain Ti3C2TxA colloid; mixing Ti3C2TxColloid is dispersed in Tri-HCl solution containing polyphenol for Ti3C2TxStripping to obtain 2D Ti3C2TxA nanosheet aqueous dispersion; wherein, TxIs a surface terminal group comprising hydroxyl, fluorine, oxygen, or a combination thereof;

(3) alternately immersing the substrate in the vitamin nano crystal suspension obtained in the step (1) and the Ti obtained in the step (2)3C2TxIn the nano-sheet aqueous dispersion, two dispersions are self-assembled layer by layer through hydrogen bonds, and a flame-retardant antistatic coating is constructed on the surface of a substrate.

2. The method according to claim 1, wherein the cellulose nanocrystal suspension in step (1) has a solid content of 0.2 to 0.4 wt%.

3. The method as claimed in claim 1, wherein the dispersion liquid in the step (1) comprises the following components in parts by weight: 5-10 parts of phosphoric acid, 10-12 parts of nitrogen-containing compound and 1-3 parts of cellulose nanocrystal.

4. The method of claim 1, wherein Ti in step (2)3C2TxThe concentration of the nano-sheet aqueous dispersion is 1-5 mg/mL.

5. The method of claim 1, wherein in step (2), the polyphenol is mixed with Ti3C2TxThe mass ratio of the colloid is 1: (0.6-4).

6. The method according to claim 1, wherein the mass ratio of the phytic acid to the cellulose nanocrystals in the dispersion of step (1) is (1-10): 3.

7. the method of claim 1, wherein the substrate is glass reinforced plastic.

8. The method according to claim 1, wherein in the step (3), the substrate is alternately immersed into the two dispersions 10 to 20 times.

9. A flame retardant, antistatic coating comprising the components: coating cellulose nanocrystals and MXene stripped by the aid of polyphenol by using a phosphoric acid-containing doped nitrogen-containing polymer;

wherein, the phosphorus acid doped nitrogen-containing polymer coated cellulose nanocrystal is prepared by the following steps: taking the cellulose nanocrystals as a template, phosphoric acid as doping acid and a nitrogen-containing compound as a monomer, and carrying out in-situ oxidative polymerization in an aqueous solution to coat the cellulose nanocrystals;

the MXene with polyphenol assisted stripping is prepared by the following process: selective etching of Ti with hydrochloric acid and lithium fluoride3AlC2MXene, separating and collecting solid to obtain Ti3C2TxA colloid; mixing Ti3C2TxColloid is dispersed in Tri-HCl solution containing polyphenol for Ti3C2TxStripping to obtain 2D Ti3C2TxA nanosheet aqueous dispersion; wherein, TxIs a surface terminal group comprising hydroxyl, fluorine, oxygen or a combination thereof.

10. Use of the flame-retardant antistatic coating according to claim 9 in the fields of rail transit, ships, aerospace.

Technical Field

The invention relates to a cellulose nanocrystal/MXene self-assembled flame-retardant antistatic coating and application thereof to glass fiber reinforced plastics, and belongs to the field of halogen-free flame retardance.

Background

The glass fiber reinforced plastic has a series of advantages of high specific strength, high specific modulus, chemical corrosion resistance, fatigue resistance and the like, and is widely applied to the aspects of transportation, medical treatment, construction, sports goods, aerospace, national defense and military industry and the like. However, the resin matrix is a flammable material, which results in poor flame retardancy of the glass fiber reinforced plastic, and the glass fiber reinforced plastic is easily burnt in open fire, and releases a large amount of heat, dense smoke and toxic gases in the burning process, thereby causing economic loss and threatening the life safety of human beings. The development process is simple, the flame retardant efficiency is high, and the effective method for reducing the fire risk of the glass fiber reinforced plastic is used for improving the flame retardant property of the glass fiber reinforced plastic.

Mxene is a novel two-dimensional nano flame retardant material, is used as a nano barrier, can effectively isolate heat and oxygen transfer, generates titanium dioxide through high-temperature oxidation, catalyzes a substrate to dehydrate into carbon, and forms a compact carbon layer to reduce heat and oxygen exchange. Meanwhile, the Mxene has metal conductivity, can reduce the volume resistivity of the base material, and plays a role in static resistance. However, when MXene is used alone, the improvement of the flame retardant performance is limited, and the MXene and other flame retardants form an ordered structure to achieve an excellent flame retardant effect. The cellulose nanocrystals are used as a bio-based carbon source, so that the char forming capability is further improved to reduce the transfer of heat and oxygen, and the flame retardant effect is achieved.

Disclosure of Invention

In order to simultaneously realize the purposes of high-efficiency flame retardance and antistatic property of the glass fiber reinforced plastic, the invention designs a cellulose nanocrystal/MXene self-assembly flame-retardant antistatic coating by adopting a layer-by-layer self-assembly method. The preparation method of the coating is simple, efficient and repeatable, and the flame retardant property and the surface antistatic property of the glass fiber reinforced plastic are improved. Layer-by-layer self-assembly means that a functional coating with a multilayer ordered structure is constructed on the surface of a base material through interaction of static electricity, hydrogen bonds, coordination bonds, hydrophobic interaction, covalent bonds and the like, so that effective coating protection is provided.

A first object of the present invention is to provide a method for preparing a cellulose nanocrystal/MXene self-assembled flame retardant antistatic coating, comprising:

(1) preparing a cellulose nanocrystal suspension by taking a cellulose nanocrystal as a template, phosphoric acid as doping acid and a nitrogen-containing compound as a monomer, and carrying out in-situ oxidative polymerization in an aqueous solution to coat the cellulose nanocrystal;

(2) selective etching of Ti with hydrochloric acid and lithium fluoride3AlC2MXene, separating and collecting solid to obtain Ti3C2TxA colloid; mixing Ti3C2TxColloid is dispersed in Tri-HCl solution containing polyphenol for Ti3C2TxStripping to obtain 2D Ti3C2TxA nanosheet aqueous dispersion; wherein, TxIs a surface terminal group comprising hydroxyl, fluorine, oxygen, or a combination thereof;

(3) alternately immersing the substrate in the vitamin nano crystal suspension obtained in the step (1) and the Ti obtained in the step (2)3C2TxIn the nano-sheet aqueous dispersion, two dispersions are self-assembled layer by layer through hydrogen bonds, and a flame-retardant antistatic coating is constructed on the surface of a substrate.

In one embodiment of the present invention, the solid content of the cellulose nanocrystal suspension in the step (1) is 0.2 wt% to 0.4 wt%.

In one embodiment of the present invention, the dispersion liquid in step (1) comprises the following components in parts by weight: 5-10 parts of phosphoric acid, 10-12 parts of nitrogen-containing compound and 1-3 parts of cellulose nanocrystal.

In one embodiment of the present invention, Ti in the step (2)3C2TxThe concentration of the nano-sheet aqueous dispersion is 1-5 mg/mL. Specifically, 2mg/mL can be selected.

In one embodiment of the present invention, the dispersion liquid in step (2) comprises the following components in parts by weight: 1-4 parts of Ti3C2TxColloid, 1-1.5 parts of polyphenol; the mass ratio of the two is (0.6-4): 1. further, polyphenol and Ti3C2TxThe mass ratio of the colloid can be specifically selected from 3: 2. 1: 2. 1: 4.

in one embodiment of the present invention, the mass ratio of the phytic acid to the cellulose nanocrystals in the dispersion of step (1) is (1-10): 3. the concrete options are 5: 3.

in one embodiment of the invention, the phosphorus-containing acid comprises one or more of hexamethylenediamine tetramethylene phosphate, phytic acid, hydroxyethylidene diphosphate, phosphorylglycolic acid.

In one embodiment of the present invention, the nitrogen-containing compound comprises one or two of aniline, pyrrole, and polythiophene.

In one embodiment of the invention, the polyphenol comprises one or more of 3, 4-dihydroxyphenylalanine, tannic acid, dopamine.

In one embodiment of the invention, the reaction temperature of the step (1) pair is 0-5 ℃, and the reaction time is 1-5 h.

In one embodiment of the present invention, the substrate may be glass fiber reinforced plastic.

In one embodiment of the present invention, in the step (3), the number of times the substrate is alternately immersed in the two dispersions is 10 to 20.

The invention provides a flame-retardant antistatic coating prepared by the method, which comprises the following components: coating cellulose nanocrystals and MXene stripped by the aid of polyphenol by using a phosphoric acid-containing doped nitrogen-containing polymer;

the phosphoric acid-containing doped nitrogen-containing polymer coated cellulose nanocrystal is prepared by the following steps: taking the cellulose nanocrystals as a template, phosphoric acid as doping acid and a nitrogen-containing compound as a monomer, and carrying out in-situ oxidative polymerization in an aqueous solution to coat the cellulose nanocrystals;

the polyphenol assisted stripped MXene is prepared by the following process: selective etching of Ti with hydrochloric acid and lithium fluoride3AlC2MXene, separating and collecting solid to obtain Ti3C2TxA colloid; mixing Ti3C2TxColloid is dispersed in Tri-HCl solution containing polyphenol for Ti3C2TxStripping to obtain 2D Ti3C2TxA nanosheet aqueous dispersion; wherein, TxIs a surface terminal group comprising hydroxyl, fluorine, oxygen or a combination thereof.

The invention also provides application of the flame-retardant antistatic coating in the fields of rail transit, ships and aerospace.

Due to the adoption of the technical scheme, the invention has the beneficial effects that:

the cellulose nanocrystal/Mxene functional coating is constructed on the surface of the glass fiber reinforced plastic by adopting a layer-by-layer self-assembly method, and the method is simple, efficient, strong in repeatability and environment-friendly; meanwhile, the problems that the glass fiber reinforced plastics are inflammable and easy to generate static electricity are solved, and the glass fiber reinforced plastics have good application prospects in the fields of rail transit, ships, aerospace and the like.

The functional coating effectively plays a synergistic effect of nano barrier of the phosphorus flame retardant catalytic char and MXene, improves the flame retardance of the glass fiber reinforced plastic, and has a Limiting Oxygen Index (LOI) of more than 27 and a heat release rate reduced by more than 40%.

The functional coating of the invention effectively exerts the high conductivity of MXene, reduces the volume resistivity of glass fiber reinforced plastics, has the number of self-assembly layers of 20, and reduces the volume resistivity to 2.2 multiplied by 1011

Drawings

FIG. 1 shows Ti obtained in example 13C2TxTransmission Electron Microscopy (TEM) images of the nanoplatelets;

FIG. 2 is an infrared (FTIR) plot of phosphorylated cellulose nanocrystals obtained in example 1;

FIG. 3 is a graph of Total Heat Release (THR) of the resulting glass fiber reinforced plastic and flame retardant glass fiber reinforced plastic of example 1;

FIG. 4 is a graph of Heat Release Rate (HRR) of the resulting glass fiber reinforced plastic and flame retardant glass fiber reinforced plastic of example 1;

FIG. 5 is a plot of Limiting Oxygen Index (LOI) of the resulting glass fiber reinforced plastic and flame-retardant glass fiber reinforced plastic of example 1.

Detailed Description

The test method comprises the following steps: the invention uses the cone calorimeter to measure the heat release rate and the total heat release amount; determining the limit oxygen index of the flame-retardant glass fiber reinforced plastic by using a limit oxygen index instrument; and measuring the volume resistivity of the glass fiber reinforced plastic and the flame-retardant glass fiber reinforced plastic by using a volume resistivity meter.

Example 1

Preparation of flame-retardant dispersion liquid:

adding 2g of lithium fluoride into 40ml of 9M hydrochloric acid, reacting at room temperature for 30min, raising the temperature to 35 ℃, and adding 2g of Ti3AlC2Reacting for 24 hours, centrifuging, collecting solid, washing with water and drying to obtain Ti3C2TxAnd (3) colloid.

0.1g of tannic acid was dissolved in 300ml of deionized water, and 0.2g of Ti was added to the solution3C2TxDispersing colloid by ultrasonic for 2 hr, centrifuging, collecting solid, washing with water, drying, and dispersing again to obtain 2mg/mL Ti3C2TxA nanosheet dispersion;

dissolving 1g of aniline monomer in 200ml of deionized water, then adding 0.5g of phytic acid and 0.3g of cellulose nanocrystals into the aniline solution, carrying out water bath ultrasonic treatment for 1h, adding 0.15g of ammonium persulfate into the mixture, reacting for 3h at 0 ℃, washing with water, drying and re-dispersing to obtain the flame-retardant cellulose nanocrystal dispersion liquid with the solid content of 0.2 wt%.

Preparation of flame-retardant antistatic coating (flame-retardant glass fiber reinforced plastic):

sequentially and respectively soaking the glass fiber reinforced plastics into Ti3C2TxRepeating the nano sheet dispersion liquid and the cellulose nano crystal dispersion liquid for 20 times, and finally drying for 24 hours at 60 ℃ to prepare the flame-retardant glass fiber reinforced plastic with the flame-retardant antistatic coating on the surface.

Mixing the above Ti3C2TxFiltering the nano-sheet dispersion liquid, and collecting solids to obtain tannic acid modified Ti3C2TxNanosheets. By TEM test, as shown in FIG. 1, the obtained tannic acid modified Ti3C2TxThe nano-sheet is of an obvious sheet structure and has a granular load, which shows that the tannic acid loads Ti3C2TxNanosheets.

And filtering the flame-retardant cellulose nanocrystal dispersion liquid, and collecting solids to obtain the phytic acid doped polyaniline coated cellulose nanocrystals. FTIR tests show that the phytic acid doped polyaniline coated cellulose nanocrystals can be successfully prepared as shown in figure 2.

The obtained flame-retardant glass fiber reinforced plastic is subjected to heat release rate test, total heat release amount test and limited oxygen index test and determination, and is respectively shown in figures 3-5. Specific performance results are shown in table 1.

Example 2

Preparation of flame-retardant dispersion liquid:

adding 2g of lithium fluoride into 40ml of 9M hydrochloric acid, reacting at room temperature for 30min, raising the temperature to 35 ℃, and adding 2g of Ti3AlC2Reacting for 24 hours, centrifuging, collecting solid, washing with water and drying to obtain Ti3C2TxAnd (3) colloid.

0.1g of tannic acid was dissolved in 300ml of deionized water, and 0.2g of Ti was added to the solution3C2TxDispersing the colloid for 2h by ultrasonic, centrifuging, collecting the solid, washing with water, drying, and dispersing again to obtain 2mg/ml Ti3C2TxA nanosheet dispersion;

dissolving 1g of aniline monomer in 200ml of deionized water, then adding 0.8g of phytic acid and 0.3g of cellulose nanocrystals into the aniline solution, carrying out water bath ultrasonic treatment for 1h, adding 0.15g of ammonium persulfate into the mixture, reacting for 3h at 0 ℃, washing with water, drying and re-dispersing to obtain the flame-retardant cellulose nanocrystal dispersion liquid with the solid content of 0.2 wt%.

Preparing the flame-retardant glass fiber reinforced plastic: referring to example 1, a flame retardant glass fiber reinforced plastic was prepared. Specific performance parameters are shown in table 1.

Example 3

Preparation of flame-retardant dispersion liquid:

adding 2g of lithium fluoride into 40ml of 9M hydrochloric acid, reacting at room temperature for 30min, raising the temperature to 35 ℃, and adding 2g of Ti3AlC2Reacting for 24 hours, centrifuging, collecting solid, washing with water and drying to obtain Ti3C2TxAnd (3) colloid.

0.1g of tannic acid was dissolved in 300ml of deionized water, and 0.2g of Ti was added to the solution3C2TxDispersing the colloid for 2h by ultrasonic, centrifuging, collecting the solid, washing with water, drying, and dispersing again to obtain 3mg/mL Ti3C2TxA nanosheet dispersion;

dissolving 1g of aniline monomer in 200ml of deionized water, then adding 0.5g of phytic acid and 0.3g of cellulose nanocrystals into the aniline solution, carrying out ultrasonic treatment in a water bath for 1h, adding 0.15g of ammonium persulfate into the mixture, reacting for 3h at 0 ℃, washing with water, drying and re-dispersing to obtain the flame-retardant cellulose nanocrystal dispersion liquid with the solid content of 0.2 wt%.

Preparing the flame-retardant glass fiber reinforced plastic: referring to example 1, a flame retardant glass fiber reinforced plastic was prepared. Specific performance parameters are shown in table 1.

Example 4

Preparation of flame-retardant dispersion liquid:

adding 2g of lithium fluoride into 40ml of 9M hydrochloric acid, reacting at room temperature for 30min, raising the temperature to 35 ℃, and adding 2g of Ti3AlC2Reacting for 24 hours, centrifuging, collecting solid, washing with water and drying to obtain Ti3C2TxAnd (3) colloid.

0.1g of tannic acid was dissolved in 300ml of deionized water, and 0.2g of Ti was added to the solution3C2TxDispersing the colloid for 2h by ultrasonic, centrifuging, collecting the solid, washing with water, drying, and dispersing again to obtain 2mg/mL Ti3C2TxA nanosheet dispersion;

dissolving 1g of aniline monomer in 200ml of deionized water, then adding 0.5g of phytic acid and 0.3g of cellulose nanocrystals into the aniline solution, carrying out water bath ultrasonic treatment for 1h, adding 0.15g of ammonium persulfate into the mixture, reacting for 3h at 0 ℃, washing with water, drying and re-dispersing to obtain the flame-retardant cellulose nanocrystal dispersion liquid with the solid content of 0.4 wt%.

Preparing the flame-retardant glass fiber reinforced plastic: referring to example 1, a flame retardant glass fiber reinforced plastic was prepared. Specific performance parameters are shown in table 1.

Example 5

Preparation of flame-retardant dispersion liquid:

adding 2g of lithium fluoride into 40ml of 9M hydrochloric acid, reacting at room temperature for 30min, raising the temperature to 35 ℃, and adding 2g of Ti3AlC2Reacting for 24 hours, centrifuging, collecting solid, washing with water and drying to obtain Ti3C2TxAnd (3) colloid.

0.15g of tannic acid was dissolved in 300ml of deionized water, and 0.2g of Ti was added to the solution3C2TxDispersing the colloid for 2h by ultrasonic, centrifuging, collecting the solid, washing with water, drying, and dispersing again to obtain 2mg/mL Ti3C2TxA nanosheet dispersion;

dissolving 1g of aniline monomer in 200ml of deionized water, then adding 0.5g of phytic acid and 0.3g of cellulose nanocrystals into the aniline solution, carrying out water bath ultrasonic treatment for 1h, adding 0.15g of ammonium persulfate into the mixture, reacting for 3h at 0 ℃, washing with water, drying and re-dispersing to obtain the flame-retardant cellulose nanocrystal dispersion liquid with the solid content of 0.2 wt%.

Preparing the flame-retardant glass fiber reinforced plastic: referring to example 1, a flame retardant glass fiber reinforced plastic was prepared. Specific performance parameters are shown in table 1.

TABLE 1 thickness of the coatings in the glass fiber reinforced plastics obtained in the different examples and results of flame-retardant and antistatic properties

The preparation method is simple and controllable, the adopted flame retardant is green and environment-friendly, and the prepared glass fiber reinforced plastic has good heat resistance and flame retardance, and can reduce the resistance and achieve the antistatic effect.

Example 6 different Ti3C2TxCoating prepared by nano-sheet concentration

Single factor control: with reference to example 1, only Ti3C2TxThe concentration of the nano sheets in the nano sheet dispersion liquid is respectively replaced by 1mg/mL and 5mg/mL from 2mg/mL, and other conditions are not changed, so that the flame-retardant glass fiber reinforced plastic with the flame-retardant antistatic coating on the surface is prepared.

The properties of the resulting flame-retardant poly (glass fiber reinforced plastic) were measured and the results are shown in Table 2.

TABLE 2 Ti of different nanosheet concentrations3C2TxPerformance results for coatings made from nanoplate dispersions

It can be seen that the other conditions are unchanged, Ti3C2TxThe concentration of the nano-sheets is increased, the total heat release amount and the heat release rate are reduced, the limited oxygen index is improved, the flame retardance is good, and meanwhile, the resistance is reduced, but the thickness of the coating is increased.

EXAMPLE 7 selection and quantity of different polyphenols for the preparation of coatings

Single factor control: with reference to example 1, only Ti3C2TxIn the preparation process of the nano-sheet dispersion liquid, the polyphenol substances are respectively replaced by 3, 4-dihydroxyphenylalanine and dopamine from tannic acid, and other conditions are unchanged, so that the flame-retardant glass fiber reinforced plastic with the flame-retardant antistatic coating on the surface is prepared.

The properties of the resulting flame-retardant poly (glass fiber reinforced plastic) were measured and the results are shown in Table 3.

TABLE 3 Performance results for coatings obtained with different polyphenolic species selection

Thus, 3, 4-dihydroxyphenylalanine and dopamine are modified to strip Ti3C2TxThe thickness of the nano-sheet is increased, and the flame retardant property is reduced compared with that of tannic acid.

Single factor control: with reference to example 1, only Ti3C2TxThe dosage of the tannic acid in the nano sheet dispersion liquid is respectively changed from 0.1g (the mass ratio of the tannic acid to MXene is 1: 2) to 0.05g (the mass ratio of the tannic acid to the MXene is 1: 4) and 0.3g (the mass ratio of the tannic acid to the MXene is 3: 2), and other conditions are not changed to prepare the flame-retardant glass steel with the surface provided with the flame-retardant antistatic coating.

The properties of the resulting flame-retardant poly (glass fiber reinforced plastic) were measured and the results are shown in Table 4.

TABLE 4 Performance results for coatings obtained with different amounts of polyphenols

Therefore, the using amount of the tannic acid is 0.05g, the total heat release amount and the heat release rate of the glass fiber reinforced plastic are high, the using amount of the tannic acid is increased to 0.3g, the flame retardant property is good, but the coating is thick and the resistance is large.

Example 8 preparation of coatings from cellulose nanocrystal dispersions of different cellulose nanocrystal concentrations

Single factor control: referring to example 1, flame-retardant glass fiber reinforced plastic with a flame-retardant antistatic coating on the surface was prepared by replacing the mass concentration of cellulose nanocrystals in the cellulose nanocrystal dispersion from 0.2 wt% to 0.05 wt% and 0.5 wt%, respectively, without changing other conditions.

The properties of the resulting flame-retardant poly (glass fiber reinforced plastic) were measured and the results are shown in Table 5.

TABLE 5 Performance results for coatings obtained from cellulose nanocrystal dispersions of different cellulose nanocrystal concentrations

It can be seen that the concentration of the cellulose nanocrystal dispersion is too low, the flame retardant property of the glass fiber reinforced plastics is poor, the concentration is increased to 0.5 wt%, the heat release is reduced, but the resistance is increased, and the antistatic property is poor.

Example 9 selection and amount of different phosphoric acid-containing species in cellulose nanocrystal dispersions to prepare coatings

Single factor control: referring to example 1, the flame-retardant glass fiber reinforced plastic with the flame-retardant and antistatic coating on the surface was prepared by replacing only the phosphoric acid with the diamine tetramethylene phosphoric acid and the hydroxyethylidene diphosphonic acid, respectively, under otherwise unchanged conditions.

The properties of the resulting flame-retardant poly (glass fiber reinforced plastic) were measured and the results are shown in Table 6.

TABLE 6 Performance results for coatings selected from different phosphoric acid-containing species in cellulose nanocrystal dispersions

Therefore, different phosphorus-containing doping acids can improve the flame retardance of the glass fiber reinforced plastic, the flame retardant efficiency of the hexamethylenediamine tetramethylene phosphonic acid and the hydroxyethylidene diphosphonic acid is low, and the total heat release amount and the maximum heat release rate are high.

Single factor control: referring to example 1, the flame-retardant glass fiber reinforced plastic with the surface being the flame-retardant antistatic coating was prepared by replacing the amount of phytic acid used with 0.1g and 1g, respectively, from 0.5g (the mass ratio of phytic acid to cellulose nanocrystals was 5: 3), and the other conditions were not changed.

The properties of the resulting flame-retardant poly (glass fiber reinforced plastic) were measured and the results are shown in Table 7.

TABLE 7 Performance results for coatings obtained with different amounts of phosphoric acid in vitamin nanocrystalline dispersions

Therefore, only the phytic acid is used in a low amount, the flame retardant property is poor, the total heat release amount and the maximum heat release rate are high, the phytic acid content is increased, the flame retardant property is good, and the coating is thick.

Example 10 selection and dosage of different Nitrogen-containing Compounds in cellulose nanocrystal Dispersion to prepare coatings

Single factor control: referring to example 1, the flame-retardant glass fiber reinforced plastic with the flame-retardant antistatic coating on the surface was prepared by replacing the nitrogen-containing compound with pyrrole and polythiophene, respectively, only by aniline, without changing other conditions.

The properties of the resulting flame-retardant poly (glass fiber reinforced plastic) were measured and the results are shown in Table 8.

TABLE 8 Performance results for coatings obtained with different nitrogen-containing compound species selection in cellulose nanocrystal dispersions

Therefore, different nitrogen-containing compounds can reduce the surface resistance of the glass fiber reinforced plastic, improve the antistatic property, reduce the heat release and enhance the flame retardance.

Single factor control: referring to example 1, the flame-retardant glass fiber reinforced plastic with the surface provided with the flame-retardant antistatic coating is prepared by replacing the use amount of aniline from 1g (mass ratio of aniline to cellulose nanocrystal is 10: 3) with 0.3 and 2 respectively, and keeping the other conditions unchanged.

The properties of the flame-retardant glass fiber reinforced plastic obtained were measured and the results are shown in Table 9.

TABLE 9 Performance results for coatings obtained with different amounts of nitrogen-containing compound in the cellulose nanocrystal dispersion

Therefore, the content of 0.3g of aniline is increased along with the content of aniline, the resistivity of the glass fiber reinforced plastic is reduced, the antistatic property is improved, and the flame retardance is good.

Although the present invention has been described in connection with the preferred embodiments, it should be understood that it is not limited thereto, but is capable of numerous changes, substitutions and alterations by one skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

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