CN104788575A - Cellulose derivative containing DOPO structure, and preparation method thereof - Google Patents

Abstract

The invention discloses a cellulose derivative containing DOPO structure and a preparation method thereof. The method uses cellulose or cellulose derivatives as starting materials; the reaction is carried out in a homogeneous solution of cellulose or cellulose derivatives; The functional groups of DOPO are reacted to prepare DOPO-containing cellulose derivatives. The DOPO substitution degree of the obtained product can be adjusted within the range of 0.1-2.3; the DOPO-containing cellulose derivative can be dissolved in an organic solvent and processed into a transparent cellulose material, such as a fiber, a film or a coating material, which has important Value.

Description

A kind of cellulose derivative containing DOPO structure and preparation method thereof

technical field

The invention relates to a method for modifying natural polymer materials, in particular to a cellulose derivative containing DOPO structure and a preparation method thereof.

Background technique

With the depletion of non-renewable resources such as oil and coal on the earth and the increasing pollution of the human living environment, how to effectively use renewable resources has become one of the main focuses of scientists all over the world. As the natural polymer with the largest reserves in nature, cellulose has attracted widespread attention due to its advantages of abundant sources, renewable, easy to degrade and non-polluting. However, due to the characteristics of natural cellulose's own aggregate structure (high crystallinity, a large number of hydrogen bonds between molecules and intramolecules), cellulose can neither be melted nor dissolved, and its processing performance is poor, which greatly limits the natural Cellulose application. Each structural unit in cellulose contains three hydroxyl groups, which create favorable conditions for the modification of cellulose. Converting hydroxyl groups into other groups through chemical reactions can not only greatly improve the processability of cellulose, but also endow cellulose with some unique functions. At present, the reactions carried out on cellulose include: esterification reaction, etherification reaction, Michael addition reaction, oxidation reaction and grafting reaction. The appearance of these cellulose derivatives has greatly expanded the application fields of cellulose materials. For example, cellulose esters are widely used in coatings, plastics, spinning and other fields; cellulose ethers are important additives in the fields of food, daily chemicals, medicine, printing and dyeing, concrete engineering, and drilling engineering.

Contents of the invention

The object of the present invention is to provide a cellulose derivative containing DOPO structure and a preparation method thereof.

The method for preparing cellulose derivatives containing DOPO structure provided by the present invention is method A or method B;

Described method A comprises the steps:

1) reacting the compound whose repeating structural unit is represented by formula I with R ₁ '-X in a solvent to obtain an intermediate compound whose repeating structural unit is represented by formula II;

In the formula I, R is at least one selected from hydrogen, acetyl, propionyl, butyryl, methyl and ethyl;

In formula II, R ₁ ' is a C2-C4 alkenyl group; X is selected from at least one of an acid chloride group, an acid anhydride group and an isocyanate group;

2) In the presence of a catalyst, react the intermediate compound of the repeating structural unit obtained in step 1) as shown in formula II with DOPO in a solvent, and obtain the cellulose derivative containing the DOPO structure after the reaction is completed;

Described method B comprises the steps:

3) React OCN-R ₂ '-NCO and DOPO in a solvent, and the compound shown in formula III is obtained after the reaction is completed;

In the formula III, R ₂ ' is selected from C1-C6 alkyl, phenyl, phenyl derivatives, naphthyl, cyclohexyl and at least one of;

4) reacting the compound represented by formula III obtained in step 3) with the compound represented by formula I as a repeating structural unit in a solvent, and the cellulose derivative containing the DOPO structure is obtained after the reaction is completed;

In the formula I, R is at least one selected from hydrogen, acetyl, propionyl, butyryl, methyl and ethyl.

In the above methods A and B, the compound as shown in formula I is cellulose or cellulose derivatives;

In the definition of formula I, when R is hydrogen, the compound as shown in formula I is cellulose;

When R is selected from at least one of acetyl, propionyl, butyryl, methyl and ethyl, the compound shown in formula I is a cellulose derivative;

Wherein, the cellulose is selected from at least one of microcrystalline cellulose, cotton pulp cellulose, wood pulp cellulose, bamboo pulp, absorbent cotton, bagasse, wood and cellulose prepared from plant straws;

The cellulose derivative is selected from at least one of cellulose ethers and cellulose esters containing substituents; wherein, the substituents are selected from at least one of C1-C4 alkyl groups; specifically selected from cellulose diacetate , at least one of cellulose acetate butyrate, cellulose propionate, cellulose butyrate, methyl cellulose and ethyl cellulose;

The Chinese standard name of DOPO used is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, which is a phosphaphenanthrene heterocyclic compound with the unique characteristics of the phosphaphenanthrene group. Such as non-coplanarity, interaction with intramolecular or intermolecular groups, bulky structure, molecular polarity, etc.

The solvents are all selected from at least one of ionic liquids, acetone, chloroform, N,N-dimethylsulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and pyridine;

Wherein, the ionic liquid is an organic molten salt formed by imidazole or pyridinium cations and anions with a melting point lower than 100°C; preferably an organic molten salt that can dissolve cellulose; also preferably, the present invention can use mixed ions The liquid dissolves cellulose, wherein the mixed ionic liquids can all be ionic liquids capable of dissolving cellulose, or a mixture of ionic liquids capable of dissolving cellulose and ionic liquids that do not dissolve cellulose;

Wherein, the cation is specifically selected from 1-ethyl-3-methylimidazolium cation, 1-propyl-3-methylimidazolium cation, 1-allyl-3-methylimidazolium cation, 1-butyl- Any one of 3-methylimidazolium cation, N-ethylpyridinium cation, N-butylpyridine cation and N-n-hexylpyridinium cation;

The anion is specifically selected from any one of chloride ion, bromide ion, formate ion, acetate ion, propionate ion, butyrate ion and methyl phosphate ion;

According to the present invention, the ionic liquids are used alone or in combination, or in combination with co-solvents such as DMSO, DMF, DMAc or N-methylpyrrolidone.

The R ₁ '-X is selected from acryloyl chloride, methacryloyl chloride, crotonoyl chloride, acrylic anhydride, methacrylic anhydride, maleic anhydride, itaconic anhydride, allyl isocyanate and vinyl isocyanate at least one of

The catalyst is selected from at least one of triethylamine, imidazole and pyridine;

The OCN-R _2' -NCO is selected from 4,4'-diphenylmethane diisocyanate (MDI), 2,4-toluene diisocyanate, 1,6-hexamethylene diisocyanate, 1,5-naphthalene diisocyanate and At least one of trans-1,4-cyclohexyl diisocyanate.

In step 1) of the method A, in the reaction step, the temperature is 0-150°C, specifically 30-80°C, more specifically 50°C, and the time is 0.1-48 hours, specifically 1-10 hours, more specifically 2 hours ;

In the step 2), the catalyst is used in an amount of 0.01-30% of the mass of DOPO, specifically 1-15%.

In the reaction step, the temperature is 0-200°C, specifically 80°C, and the time is 0.1-48 hours, specifically 12 hours;

The mass ratio of the repeating structural unit such as the compound represented by formula I, R ₁ '-X and DOPO is 1:0.05-10.0:0.01-10.0, specifically 1:0.28:1.2, 1:0.56:3.59, 1: 1.68:6, 1:1.68:2, 1:1.68:3.55 or 1:0.28-1.68:1.2-3.55;

In step 3) of the method B, in the reaction step, the temperature is -20-200°C, specifically 10-50°C, more specifically 30°C, and the time is 0.1-48 hours, specifically 1-20 hours, specifically 8 hours ;

In the step 4) in the reaction step, the temperature is 0-160°C, specifically 50-100°C, more specifically 80°C, and the time is 0.1-72 hours, specifically 1-10 hours, more specifically 2 hours;

The repeating structural units such as the compound represented by formula I, OCN-R ₂ '-NCO and DOPO are used in an amount ratio of 1g:0.05-10.0g:0.01-10.0g, specifically 1:0.1:0.09, 1:0.4: 0.4, 1:0.5:0.4, 1:0.8:0.7, 1:1:0.9 or 1:0.1-1:0.09-0.9;

In addition, the cellulose derivatives containing DOPO structure prepared according to the method provided by the present invention also belong to the protection scope of the present invention. Wherein, in the cellulose derivatives containing DOPO structure, the degree of substitution of DOPO groups (the number of substituent groups in each glucose unit) is 0.1-2.3, specifically 0.12, 0.16, 0.17, 0.33, 0.56, 0.59, 0.94, 0.97, 0.98 or 0.12-0.98.

The homogeneous solution composed of the above-mentioned cellulose derivatives containing DOPO structure and organic solvent provided by the present invention also belongs to the protection scope of the present invention, wherein the organic solvent is selected from DMSO, DMF, pyridine, chloroform, tetrahydrofuran and DMAc at least one of;

The mass percent concentration of the homogeneous solution is 1-40%, specifically 3-30%.

In addition, the material prepared from the above-mentioned homogeneous solution also belongs to the protection scope of the present invention, wherein the material is a transparent material, specifically a film; the heat release rate of the film material is greatly reduced compared with the raw material, and the carbon The residual amount is greatly increased; when burning, the membrane material has obvious combustion self-extinguishing phenomenon.

The method for preparing a cellulose derivative containing a DOPO structure provided by the present invention uses cellulose or a cellulose derivative as a starting material, and is carried out in a homogeneous solution of cellulose or a cellulose derivative; DOPO is introduced into cellulose or its derivatives to prepare DOPO-containing cellulose derivatives. The DOPO-containing cellulose derivatives can be dissolved in organic solvents and processed into transparent cellulose-based materials, such as fibers, films or coating materials, which have important application value.

Description of drawings

Fig. 1 is the ¹ H NMR spectrum of DOPO-type cellulose derivatives, cellulose acrylate and DOPO obtained in Example 3.

FIG. 2 is a ¹ H NMR spectrum of the DOPO-type cellulose derivative obtained in Example 8. FIG.

Figure 3 shows the cellulose membrane (left) prepared with ionic liquid AmimCl as solvent and the DOPO-type cellulose derivative membrane (right) prepared with DMF as solvent.

Figure 4 shows the combustion phenomenon of cellulose film (left) and DOPO-type cellulose derivative film (right).

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to the following examples. The methods are conventional methods unless otherwise specified. The raw materials can be obtained from open commercial channels unless otherwise specified.

Embodiment 1, method A prepares the method for the cellulose derivative containing DOPO structure

(1) 1 g of microcrystalline cellulose was added to 19 g of ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl), and dissolved at 80°C with mechanical stirring at 400 rpm for 1 hour. The cellulose solution was placed in an oil bath at 50° C., and after being stabilized for half an hour, 0.28 g of acryloyl chloride was added thereto and reacted with mechanical stirring at 300 rpm for 2 hours. After the reaction, the intermediate product cellulose acrylate with a substitution degree of 0.16 was obtained through precipitation, washing and drying.

(2) Dissolve 1.2g DOPO in 5.0g DMSO, add triethylamine accounting for 1% of DOPO mass as a catalyst, dissolve 1g of cellulose acrylate in step (1) in 19g DMSO, slowly Add it dropwise into the DOPO solution, react at 80°C for 12 hours, precipitate with methanol, wash and dry, and obtain a DOPO-type cellulose derivative with a substitution degree of 0.16.

Embodiment 2, method A prepares the method for the cellulose derivative containing DOPO structure

(1) 1 g of microcrystalline cellulose was added to 19 g of ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl), and dissolved at 80°C with mechanical stirring at 400 rpm for 1 hour. The cellulose solution was placed in an oil bath at 50° C., and after being stabilized for half an hour, 0.56 g of acryloyl chloride was added thereto and reacted with mechanical stirring at 300 rpm for 2 hours. After the reaction, the intermediate product cellulose acrylate with a substitution degree of 0.56 was obtained through precipitation, washing and drying.

(2) Dissolve 3.59g DOPO in 5.0g DMSO, add triethylamine accounting for 1% of DOPO mass as a catalyst, dissolve 1g of cellulose acrylate in step (1) in 19g DMSO, slowly Add it dropwise into the DOPO solution, react at 80°C for 12 hours, precipitate with methanol, wash and dry, and obtain a DOPO-type cellulose derivative with a substitution degree of 0.56.

Embodiment 3, method A prepares the method for the cellulose derivative containing DOPO structure

(1) 1 g of microcrystalline cellulose was added to 19 g of ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl), and dissolved at 80°C with mechanical stirring at 400 rpm for 1 hour. The cellulose solution was placed in an oil bath at 50° C., and after being stabilized for half an hour, 1.68 g of acryloyl chloride was added thereto and reacted with mechanical stirring at 300 rpm for 2 hours. After the reaction, the intermediate product cellulose acrylate with a substitution degree of 0.94 was obtained through precipitation, washing and drying.

(2) Dissolve 6.0g DOPO in 9.0g DMSO, add triethylamine accounting for 1% of DOPO mass as a catalyst, dissolve 1g of cellulose acrylate in step (1) in 19g DMSO, slowly Add it dropwise into the DOPO solution, react at 80°C for 12 hours, precipitate with methanol, wash and dry, and obtain the target product DOPO-type cellulose derivative with a substitution degree of 0.94.

The chemical structures of DOPO-type cellulose derivatives and intermediate compounds were confirmed by ¹ HNMR (see Figure 1). As shown in the spectrum, the peak between δ=5.6-6.5ppm is the hydrogen (3H) on the olefin double bond, and the peak at this position proves that acrylate has been successfully introduced into the cellulose molecular chain; δ=7.0-8.3 The peak between ppm is the hydrogen (10H) on the DOPO molecule. It can be proved that DOPO has been successfully introduced into the cellulose molecular chain.

Embodiment 4, method A prepares the method for the cellulose derivative containing DOPO structure

(1) 3g of wood pulp cellulose was added to 97g of 1-butyl-3-methylimidazolium chloride (BmimCl), and dissolved at 80°C with mechanical stirring at 400 rpm for 2 hours. The cellulose solution was placed in an oil bath at 50° C., and after being stabilized for half an hour, 5.04 g of acryloyl chloride was added thereto and reacted with mechanical stirring at 300 rpm for 2 hours. After the reaction, the cellulose acrylate with a substitution degree of 0.97 can be obtained through precipitation, washing and drying.

(2) Dissolve 6.0g DOPO in 9.0g DMSO, and add triethylamine accounting for 1% of DOPO mass as a catalyst. Dissolve 1 g of cellulose acrylate in step (1) in 19 g of DMSO, and slowly add it dropwise to the DOPO solution. React at 80°C for 12 hours, methanol precipitates, wash and dry to obtain a DOPO-type cellulose derivative with a substitution degree of 0.97.

Embodiment 5, method A prepares the method for the cellulose derivative containing DOPO structure

(1) Add 48g of ionic liquid AmimCl to 2g of cotton pulp cellulose, and dissolve it for 2 hours at 80°C with mechanical stirring at 400 rpm. The cellulose solution was placed in an oil bath at 50° C., and after being stabilized for half an hour, 3.36 g of acryloyl chloride was added thereto and reacted with mechanical stirring at 300 rpm for 2 hours. After the reaction, the cellulose acrylate with a substitution degree of 0.98 can be obtained through water precipitation, washing and drying.

(2) Dissolve 7.1g DOPO in 10.0g DMSO, and add triethylamine accounting for 1% of DOPO mass as a catalyst. Dissolve 1 g of cellulose acrylate in step (1) in 19 g of DMSO, and slowly add it dropwise to the DOPO solution. Reacted at 80°C for 12 hours, precipitated with methanol, washed and dried to obtain a DOPO-type cellulose derivative with a substitution degree of 0.98.

Embodiment 6, method B prepares the method for the cellulose derivative containing DOPO structure

1) Dissolve 0.07g DOPO in 5g DMF, and 0.08g 4,4'-diphenylmethane diisocyanate (MDI) in 5g DMF; slowly add the DOPO solution dropwise into the solution, and react with magnetic stirring at 30°C After 8 hours, a compound containing DOPO structure and terminal isocyanate group was obtained.

2) Dissolve 0.76g of cellulose diacetate in 10g of DMF, and add the above-mentioned compound containing DOPO structure, react at 80°C for 2 hours, precipitate with methanol, wash and dry to obtain DOPO-type cellulose acetate with a substitution degree of 0.04 .

Embodiment 7, method B prepares the method for the cellulose derivative containing DOPO structure

1) Dissolve 0.34g DOPO in 10g DMF, and 0.39g MDI in 10g DMF; slowly add the DOPO solution dropwise into the solution, and react with magnetic stirring at 30°C for 8 hours to obtain a DOPO structure with an isocyanate terminal group base compound.

2) Dissolve 0.76g of cellulose diacetate in 10g of DMF, and add the compound containing DOPO structure and terminal isocyanate group obtained in step 1) into it, react at 80°C for 2 hours, precipitate with methanol, wash and dry to obtain replacement DOPO type cellulose acetate with a degree of 0.17.

Embodiment 8, method B prepares the method for the cellulose derivative containing DOPO structure

1) Dissolve 0.67g DOPO in 10g DMF, and 0.77g MDI in 10g DMF; slowly add the DOPO solution dropwise into the solution, and react with magnetic stirring at 30°C for 8 hours to obtain a DOPO structure with an isocyanate terminal group base compound.

2) Dissolve 0.76g of cellulose diacetate in 10g of DMF, and add the compound containing DOPO structure and terminal isocyanate group obtained in step 1) into it, react at 80°C for 2 hours, precipitate with methanol, wash and dry to obtain replacement DOPO type cellulose acetate with a degree of 0.59.

The chemical structure of DOPO-type cellulose derivatives was confirmed by ¹ HNMR (see Figure 2). As shown in the spectrum, the peak between δ=7.0-8.8ppm is the proton peak on the benzene ring in DOPO and MDI. It can be proved that DOPO has been successfully introduced into the cellulose molecular chain.

Embodiment 9, method B prepares the method for the cellulose derivative containing DOPO structure

1) Dissolve 0.67g DOPO in 10g DMF, 0.77g MDI in 10g DMF; slowly drop the DOPO solution into the MDI solution, and stir the reaction at 30°C for 8 hours to obtain the structure containing DOPO and the end group is isocyanate base compound.

2) Dissolve 0.76g of cellulose diacetate in 10g of DMF, and add the compound containing DOPO structure and terminal isocyanate group obtained in step 1) into it, react at 80°C for 2 hours, precipitate with methanol, wash and dry to obtain DOPO-type cellulose acetate with a degree of substitution of 0.58.

Embodiment 10, method B prepares the method for the cellulose derivative containing DOPO structure

1) Dissolve 0.17g DOPO in 10g DMF, and 0.20g MDI in 10g DMF; slowly add the DOPO solution dropwise into the MDI solution, and react with magnetic stirring at 30°C for 8 hours to obtain a structure containing DOPO and an end group of Isocyanate-based compounds.

2) Dissolve 0.47g of ethyl cellulose (the degree of ethyl substitution is 2.6) in 10g of DMF, and add the compound containing DOPO structure and terminal isocyanate group obtained in step 1) into it, react at 80°C for 2 hours, methanol Precipitate, wash and dry to obtain DOPO ethyl cellulose with a substitution degree of 0.12.

Embodiment 11, method B prepares the method for the cellulose derivative containing DOPO structure

1) Dissolve 0.39g DOPO in 10g DMF, and 0.45g MDI in 10g DMF; slowly add the DOPO solution dropwise into the MDI solution, and react with magnetic stirring at 30°C for 8 hours to obtain a structure containing DOPO and an end group of Isocyanate-based compounds.

2) 0.56g of cellulose acetate butyrate (the degree of substitution of acetyl group is 0.72, the degree of substitution of butyryl group is 1.36) is dissolved in 10g of DMF, and the compound obtained in step 1) containing the DOPO structure and the terminal group is isocyanate group is added to it. React at 80°C for 2 hours, methanol precipitates, wash and dry to obtain DOPO-type cellulose acetate butyrate with a substitution degree of 0.33.

Embodiment 12, solubility of DOPO type cellulose derivatives and transparent material products:

DOPO-type cellulose greatly improves the solubility of cellulose after introducing DOPO as a large group.

The DOPO type cellulose derivative obtained in Example 4 with a degree of substitution of DOPO of 0.97 was dissolved in DMSO, DMF, pyridine and chloroform. It can be seen that the compound can be dissolved rapidly and can be processed into a transparent cellulose base film material (see accompanying drawing 3). As shown in the figure, using DMF as a solvent can prepare a film material with similar transparency to cellulose.

Embodiment 13, micro-combustion calorimetry test and combustion phenomenon of DOPO type cellulose derivatives:

Microcrystalline cellulose and DOPO cellulose derivatives obtained in Examples 1, 2, 3, 6, 7 and 8 were subjected to micro-combustion calorimetry (see attached table 1).

Table 1. Micro-combustion calorimetry test data of membrane materials of DOPO-type cellulose derivatives

Among them, PHRR is the maximum heat release rate;

T _max is the highest combustion temperature;

THR is the total heat release;

HRC is heat release.

It can be seen from the table that the heat release rate of DOPO-type cellulose derivatives is greatly reduced after the introduction of such a large group as DOPO, while the carbon residue is greatly increased.

Compared with the raw materials, the DOPO-type cellulose derivatives obtained in Example 3 have obvious burning and self-extinguishing phenomenon (see Figure 4).

Claims (10)

1. preparing a method for the derivatived cellulose containing DOPO structure, is method A or method B;

Described method A comprises the steps:

1) by repeated structural unit such as formula the compound shown in I and R ₁'-X reacts in solvent, obtains repeated structural unit such as formula the midbody compound shown in II;

In described formula I, R is selected from least one in hydrogen, ethanoyl, propionyl, butyryl radicals, methyl and ethyl;

In formula II, R ₁' be the alkylene of C2-C4; X is selected from least one in acid chloride group, anhydride group and isocyanate group;

2) under catalyzer existent condition, step 1) gained repeated structural unit is reacted such as formula the midbody compound shown in II and DOPO in solvent, react complete and obtain the described derivatived cellulose containing DOPO structure;

Described method B comprises the steps:

3) by OCN-R ₂'-NCO and DOPO react in solvent, react complete and obtain compound shown in formula III;

In described formula III, R ₂' be selected from the alkyl of C1-C6, phenyl, phenyl derivatives, naphthyl, cyclohexyl and in at least one;

4) by compound shown in step 3) gained formula III and repeated structural unit such as formula the compound shown in I in solvent

In react, react complete and obtain the described derivatived cellulose containing DOPO structure;

In described formula I, R is selected from least one in hydrogen, ethanoyl, propionyl, butyryl radicals, methyl and ethyl.

2. method according to claim 1, is characterized in that: in described method A and B, is Mierocrystalline cellulose or derivatived cellulose containing repeated structural unit such as formula the compound shown in I;

Wherein, described Mierocrystalline cellulose is selected from least one in Microcrystalline Cellulose, cotton pulp Mierocrystalline cellulose, wood pulp cellulose, bamboo pulp, absorbent cotton, bagasse, timber and Mierocrystalline cellulose obtained from straw;

Described derivatived cellulose is selected from containing at least one in substituent ether of cellulose and cellulose ester; Wherein, described substituting group is selected from least one in C1-C4 alkyl; Specifically be selected from least one in Cellulose diacetate, cellulose acetate butyrate, cellulose propionate, cellulose butyrate, methylcellulose gum and ethyl cellulose;

Described solvent is all selected from least one in ionic liquid, acetone, chloroform, N, N-dimethyl sulfoxide (DMSO), DMF, N,N-dimethylacetamide and pyridine;

Wherein, described ionic liquid all for formed by imidazoles or pyridine type positively charged ion and negatively charged ion, fusing point is lower than organic melting salt of 100 DEG C;

Wherein, described positively charged ion is specifically selected from any one in 1-ethyl-3-methylimidazole positively charged ion, 1-propyl group-3-methyl imidazolium cation, 1-allyl group-3-methyl imidazolium cation, 1-butyl-3-methyl imidazolium cation, N-ethylpyridinium cations, N-butyl-pyridinium positively charged ion and N-n-hexyl pyridylium;

Negatively charged ion be specifically selected from chlorion, bromide anion, formate ion, acetate ion, propionate ion, butyrate ion and methyl orthophosphoric acid ion any one;

In described method A, R ₁'-X is selected from least one in acrylate chloride, methacrylic chloride, crotonyl chloride, acrylic anhydride, methacrylic anhydride, maleic anhydride, itaconic anhydride, allyl isocyanate and vinyl isocyanate;

Catalyzer is selected from least one in triethylamine, imidazoles and pyridine;

In described method B, OCN-R ₂'-NCO is selected from 4, at least one in 4 '-diphenylmethanediisocyanate, 2,4 toluene diisocyanate, hexamethylene diisocyanate, 1,5-naphthalene diisocyanate and trans-Isosorbide-5-Nitrae-cyclohexyl diisocyanate.

3. method according to claim 1 and 2, is characterized in that: described method step A 1) in reactions steps, temperature is 0-150 DEG C, is specially 30-80 DEG C, and be more specifically 50 DEG C, the time is 0.1-48 hour, is specially 1-10 hour, is more specifically 2 hours;

Described step 2) in, the consumption of catalyzer is the 0.01-30% of DOPO quality, is specially 1-15%.

In reactions steps, temperature is 0-200 DEG C, is specially 30-100 DEG C, and be more specifically 80 DEG C, the time is 0.1-48 hour, is specially 10-20 hour, is more specifically 12 hours;

Described repeated structural unit is such as formula the compound shown in I, R ₁' the mass ratio of-X and DOPO is 1:0.05-10.0:0.01-10.0.

4., according to the arbitrary described method of claim 1-3, it is characterized in that: described method step B 3) in reactions steps, temperature is-20-200 DEG C, is specially 10-50 DEG C, and be more specifically 30 DEG C, the time is 0.1-48 hour, is specially 1-20 hour, is specially 8 hours;

In described step 4) reactions steps, temperature is 0-160 DEG C, is specially 50-100 DEG C, and be more specifically 80 DEG C, the time is 0.1-72 hour, is specially 1-10 hour, is more specifically 2 hours;

Described repeated structural unit is such as formula the compound shown in I, OCN-R ₂' the amount ratio of-NCO and DOPO is 1g:0.05-10.0g:0.01-10.0g.

5. the arbitrary described method of claim 1-4 prepare containing the Mierocrystalline cellulose or derivatives thereof of DOPO structure.

6. cellulose and its derivates according to claim 5, is characterized in that: described containing in the Mierocrystalline cellulose or derivatives thereof of DOPO structure, the substitution value of DOPO group is 0.1-2.3.

7. the homogeneous phase solution that the derivatived cellulose containing DOPO structure prepared by the arbitrary described method of claim 1-4 and organic solvent form.

8. homogeneous phase solution according to claim 7, is characterized in that: described organic solvent is selected from least one in DMSO, DMF, pyridine, chloroform, tetrahydrofuran (THF) and DMAc;

The described mass percentage concentration containing DOPO structural fibers element derivative homogeneous phase solution is 1-40%, is specially 3-30%.

9. obtain contain DOPO structural fibers element derivant material by homogeneous phase solution preparation described in claim 7 or 8.

10. product according to claim 9, is characterized in that: described is transparent material containing DOPO structural fibers element derivant material, is specially film or coated material.