CN104910327B - A kind of phosphorus nitrogen cooperative flame retardant epoxy polymer and preparation method thereof - Google Patents

Abstract

The invention discloses a phosphorus-nitrogen synergistic flame-retardant epoxy polymer and a preparation method thereof. Its molecular weight is 7000-100000g/mol, and its structural formula is as follows: Wherein, R ₁ , R ₂ and R ₃ are H or methyl; X is a benzene ring or a linear alkyl group with 2 to 6 carbons; x:y:z=10~50:10~30:50~10. The polymer of the present invention has epoxy groups with high reactivity, which can be well dispersed and connected in epoxy resin through chemical bonds, avoiding the disadvantages of poor compatibility and easy migration of non-reactive flame retardant polymers . The polymer contains two flame retardant elements, P and N, and has good flame retardant effect. It can be used as a flame retardant or as an essentially flame retardant polymer, and has little effect on the mechanical properties of the material matrix. The present invention The preparation method is simple, has good repeatability, and is suitable for expanding production.

Description

A kind of phosphorus nitrogen synergistic flame retardant epoxy polymer and preparation method thereof

technical field

The invention belongs to the technical field of flame-retardant polymers, and in particular relates to a phosphorus-nitrogen synergistic flame-retardant epoxy polymer and a preparation method thereof.

Background technique

Epoxy resin, as a thermosetting polymer material with excellent performance, is widely used in coatings, adhesives, composite materials and other fields, and has a history of more than 60 years. Recent research has focused on the diversification and high-performance applications of epoxy resins, but the lack of flame retardancy has limited the development of epoxy resins in high-end fields such as electronic appliances. Therefore, most epoxy resins must undergo flame retardant treatment in practical applications to make them reach the corresponding flame retardant level stipulated by the state. At present, the most commonly used method is to solve the flammability problem of polymer materials by adding halogenated flame retardants, phosphorus-containing flame retardants and inorganic flame retardants. However, the additive flame retardants will reduce the mechanical properties and transparency of the polymer material to the resin matrix, and the combustion of halogen-containing flame retardants will also produce corrosive gases, which not only pollute the environment but also endanger human health. Over time, the flame retardant effect will be reduced due to the migration and loss of the flame retardant. Therefore, the development direction of polymer flame retardant in the future should be reactive halogen-free flame retardants.

CN101014650A discloses a kind of halogen-free flame retardant polymer foam material, in polystyrene melting process, flame retardant and organic blowing agent are introduced into polymer matrix together, used halogen-free flame retardant is a kind of containing Phosphorous cyclic compounds. However, the phosphorus-containing flame retardants used are small molecules, and this type of flame-retardant products still has the disadvantage of reducing the flame-retardant performance of the material due to the loss and migration of the flame retardant over time during use.

CN102391403 discloses a high-molecular flame-retardant polymer, which is formed by free-radical polymerization of active monomers containing two flame-retardant elements, phosphorus and nitrogen. The advantage is that it can not only be used as an additive flame retardant, At the same time, it can also be used as an intrinsically flame-retardant polymer material. However, since it is essentially an additive flame retardant, it is because the polymer chain is physically cross-linked with the resin matrix to achieve the purpose of less migration, or it cannot achieve the effect of connecting the resin matrix with chemical bonds.

Contents of the invention

The purpose of the present invention is to overcome the common shortcomings of existing additive flame retardants and provide a phosphorus-nitrogen synergistic flame-retardant epoxy polymer.

Another object of the present invention is to provide a method for preparing the above phosphorus-nitrogen synergistic flame-retardant epoxy polymer.

The present invention has adopted following technical scheme:

A phosphorus-nitrogen synergistic flame-retardant epoxy polymer with a molecular weight of 7,000 to 100,000 g/mol and a structural formula as follows:

Wherein, R ₁ , R ₂ and R ₃ are H or methyl; X is a benzene ring or a linear alkyl group with 2 to 6 carbons; x:y:z=10~50:10~30:50~10.

A preparation method of the above-mentioned phosphorus-nitrogen synergistic flame-retardant epoxy polymer, comprising the steps of:

(1) React 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), p-aminophenol and paraformaldehyde in the first solvent at 30-80°C for 4 After ~8 hours, the product is washed with methanol to obtain a phenolic intermediate, and the phenolic intermediate is reacted with methacryloyl chloride or acryloyl chloride in the presence of a second solvent and an acid-binding agent at 0~50°C for 4~ After 8 hours, the acid-binding agent salt was removed by filtration, and then the crude product was purified by washing, rotary evaporation and drying to obtain the first polymer monomer MAdiDOPO, whose structural formula is as follows:

Wherein R ₁ is H or methyl; X is a benzene ring or a linear alkyl group with 2 to 6 carbons; the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, The molar ratio of p-aminophenol to paraformaldehyde is 1:2.0～3.0:2.0～2.5, and the molar ratio of the phenolic intermediate, methacryloyl chloride or acryloyl chloride, and acid-binding agent is 1:1.5～2.0:1.2～ 2.0;

(2) Dissolve 2-amino-4-hydroxy-6-methylisocytosine (MIS) completely in the third solvent, then heat up to 90-170°C, stop heating, and then quickly add methacrylic acid-2 - Isocyanato ethyl ester (ICEMA), after stirring for 1-60min, cool with water to prevent the occurrence of polymerization reaction, precipitate with the first precipitant, and dry in vacuum to obtain white powder, that is, the second polymerizable monomer, whose structural formula is as follows:

The molar ratio of the 2-amino-4-hydroxyl-6-methylisocytosine to 2-isocyanatoethyl methacrylate is 1:0.8～2.0;

(3) Dissolve the first polymerized monomer prepared in step (1), the second polymerized monomer prepared in step (2) and glycidyl methacrylate (acrylic acid) (GMA) in the fourth solvent, and add triggering After the oxygen in the solvent is removed by bubbling nitrogen gas, the reaction is stirred at 45-95°C for 12-48 hours. After the reaction is completed, the reaction solution is concentrated and precipitated with the second precipitant to obtain the phosphorus-nitrogen synergistic Flame-retardant epoxy polymer, wherein the ratio of the total number of moles of the first polymerized monomer, the second polymerized monomer and glycidyl methacrylate (acrylate) (GMA) to the number of moles of the initiator is 100:0.2-3 , The molar ratio of the first polymerizable monomer, the second polymerizable monomer and glycidyl methacrylate (acrylate) (GMA) is 10-60:10-30:10-60.

In a preferred embodiment of the present invention, the first solvent is ethanol, methanol, tetrahydrofuran, acetone or acetonitrile, and the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide The dosage ratio of the first solvent is 1g:1-20mL.

In a preferred embodiment of the present invention, the second solvent is toluene, ethyl acetate, tetrahydrofuran, N,N-dimethylformamide, dichloromethane or dimethyl sulfoxide, and the methacryloyl chloride Or the ratio of acryloyl chloride to the second solvent is 1g:1-20mL.

In a preferred embodiment of the present invention, the acid-binding agent pyridine, triethylamine, sodium bicarbonate, sodium carbonate or sodium hydroxide.

In a preferred embodiment of the present invention, the third solvent is DMSO, DMF, dichloroethane or tetrachloroethane.

In a preferred embodiment of the present invention, the first precipitating agent is ethanol, methanol, n-hexane, n-pentane or n-heptane.

In a preferred embodiment of the present invention, the fourth solvent is toluene, tetrahydrofuran, chloroform, tetrachloroethane or dichloroethane.

In a preferred embodiment of the present invention, the initiator is ABVN, AIBN, BPO, DTBP or TBCP.

In a preferred embodiment of the present invention, the second precipitation agent is ethanol, methanol, n-hexane, n-pentane or n-heptane.

The beneficial effects of the present invention are:

1. The present invention can effectively adjust the content of phosphorus and nitrogen elements by adjusting the molar ratio of the monomer and the chain transfer agent and the reaction time, and realize the controllable design of the copolymer;

2. The polymer of the present invention has a highly reactive epoxy group, which can be well dispersed and can participate in the curing of epoxy resin through the epoxy group of GMA on the polymer chain segment, thereby passing the flame retardant element through The chemical bonds are connected in the resin matrix, thereby improving the shortcomings of the current additive flame retardants that are easy to migrate and lose;

3. The polymer of the present invention contains two flame retardant elements, P and N, and has good flame retardant effect. It can be used not only as a flame retardant, but also as an essentially flame retardant polymer, which affects the mechanical properties of the material matrix small;

4. The reaction condition of the preparation method of the present invention is mild, the preparation is simple, the conversion rate is high, the product purity is high, and it is suitable for expanding production.

Description of drawings

Fig. 1 is the proton nuclear magnetic resonance spectrogram of this flame-retardant polymer in the embodiment 1 of the present invention, and in Fig. 1, abscissa is chemical shift (ppm);

Fig. 2 is the nuclear magnetic resonance phosphorus spectrum of the flame retardant polymer in Example 1 of the present invention. In Fig. 2, the abscissa is the chemical shift (ppm).

detailed description

The technical solutions of the present invention will be further illustrated and described below through specific embodiments in conjunction with the accompanying drawings.

Example 1

Step 1, the synthesis of the first polymerized monomer (MAdiDOPO) described:

First, 43.2g (0.2mol) of DOPO, 10.9g (0.1mol) of p-aminophenol, 6.0g (0.1mol) of paraformaldehyde and 200mL of ethanol were added to a 500mL three-necked flask, and the reaction was stirred at 50°C for 5h , the product was washed with methanol to obtain a phenolic intermediate compound. Then, 33.2g (0.05mol) of the prepared phenolic intermediate 10.1g (0.10mol) of triethylamine and 100mL of dichloromethane were placed at 0°C and slowly dripped into 10.5g (0.10mol) Methacryloyl chloride, after the dropwise addition, continue to stir and react for 8 hours, filter to remove triethylamine hydrochloride, and purify the crude product by washing, rotary evaporation and drying to obtain the phosphorus nitrogen flame retardant MAdiDOPO containing active double bonds (References: CN104262398A).

Step 2, the synthesis of the second polymerized monomer (UPyMA) described:

Completely dissolve 5 g of MIS in an appropriate amount of 20 mL of DMSO, heat to 150 °C, and then take the reaction bottle out of the oil bath. Then 6.2mL ICEMA was added quickly, stirred for 20min and then cooled with water. The reaction mixture was precipitated with n-hexane and dried in vacuo to obtain a white powder, namely UPyMA (references: Yamauchi et al. Macromolecules, 2003, 36, 1083-1088 and Macromolecules, 2002, 35, 8745-8750).

Step 3, the preparation of described flame-retardant polymer:

First, 1.7g (6mmol) UPyMA, 2.56g (18mmol) GMA, 22.7g (36mmol) MAdiDOPO (ie x:y:z = 10:30:60) and 0.08g AIBN were placed in the reaction flask and passed through nitrogen gas After bubbling to remove the oxygen in the solvent, the reaction was stirred at 70° C. for 24 h. After the reaction, the reaction solution was concentrated and precipitated with methanol 2 to 3 times to obtain a white powdery solid. The characterization of the polymer is shown in Figure 1 and Figure 2: the three small packet peaks with chemical shifts from 10ppm to 13ppm are the characteristic peaks of UPy, 6ppm to 8ppm are the characteristic peaks of DiDOPO, and around 3.5ppm are the characteristic peaks of GMA. The phosphorous spectrum showed a single peak, which indicated that the target compound was synthesized correctly.

Embodiment 2-8

Experimental steps 1 and 2 are the same as in Example 1. The preparation method of step 3 is similar to that of Example 1, except that the ratio of different monomers is adjusted by adjusting the value of x:y:z, so that the ratio of phosphorus to nitrogen in the polymer is changed. The specific feeding ratio of UPyMA, GMA, and MAdiDOPO is shown in Table 1:

Table 1

Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 UPyMA 20 30 40 50 60 70 0 GMA 30 30 30 30 30 30 30 MAdiDOPO 50 40 30 20 10 0 70

Those of ordinary skill in the art will know that when the technical parameters of the present invention vary within the following ranges, it can be expected to obtain the same or similar technical effects as those of the above-described embodiments:

A phosphorus-nitrogen synergistic flame-retardant epoxy polymer with a molecular weight of 7,000 to 100,000 g/mol and a structural formula as follows:

Wherein, R ₁ , R ₂ and R ₃ are H or methyl; X is a benzene ring or a linear alkyl group with 2 to 6 carbons; x:y:z=10~50:10~30:50~10.

A preparation method of the above-mentioned phosphorus-nitrogen synergistic flame-retardant epoxy polymer, comprising the steps of:

(1) React 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), p-aminophenol and paraformaldehyde in the first solvent at 30-80°C for 4 After ~8 hours, the product is washed with methanol to obtain a phenolic intermediate, and the phenolic intermediate is reacted with methacryloyl chloride or acryloyl chloride in the presence of a second solvent and an acid-binding agent at 0~50°C for 4~ After 8 hours, the acid-binding agent salt was removed by filtration, and then the crude product was purified by washing, rotary evaporation and drying to obtain the first polymer monomer MAdiDOPO, whose structural formula is as follows:

Wherein R ₁ is H or methyl; X is a benzene ring or a linear alkyl group with 2 to 6 carbons; the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, The molar ratio of p-aminophenol to paraformaldehyde is 1:2.0～3.0:2.0～2.5, and the molar ratio of the phenolic intermediate, methacryloyl chloride or acryloyl chloride, and acid-binding agent is 1:1.5～2.0:1.2～ 2.0;

(2) Dissolve 2-amino-4-hydroxy-6-methylisocytosine (MIS) completely in the third solvent, then heat up to 90-170°C, stop heating, and then quickly add methacrylic acid-2 - Isocyanato ethyl ester (ICEMA), after stirring for 1-60min, cool with water to prevent the occurrence of polymerization reaction, precipitate with the first precipitant, and dry in vacuum to obtain white powder, that is, the second polymerizable monomer, whose structural formula is as follows:

The molar ratio of the 2-amino-4-hydroxyl-6-methylisocytosine to 2-isocyanatoethyl methacrylate is 1:0.8～2.0;

(3) Dissolve the first polymerized monomer prepared in step (1), the second polymerized monomer prepared in step (2) and glycidyl methacrylate (acrylic acid) (GMA) in the fourth solvent, and add triggering After the oxygen in the solvent is removed by bubbling nitrogen gas, the reaction is stirred at 45-95°C for 12-48 hours. After the reaction is completed, the reaction solution is concentrated and precipitated with the second precipitant to obtain the phosphorus-nitrogen synergistic Flame-retardant epoxy polymer, wherein the ratio of the total number of moles of the first polymerized monomer, the second polymerized monomer and glycidyl methacrylate (acrylate) (GMA) to the number of moles of the initiator is 100:0.2-3 , The molar ratio of the first polymerizable monomer, the second polymerizable monomer and glycidyl methacrylate (acrylate) (GMA) is 10-60:10-30:10-60.

The first solvent is ethanol, methanol, tetrahydrofuran, acetone or acetonitrile, and the ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the first solvent is 1g:1 ~20mL.

The second solvent is toluene, ethyl acetate, tetrahydrofuran, N,N-dimethylformamide, methylene chloride or dimethyl sulfoxide, and the ratio of the amount of methacryloyl chloride or acryloyl chloride to the second solvent is For 1g: 1 ~ 20mL.

The acid-binding agent pyridine, triethylamine, sodium bicarbonate, sodium carbonate or sodium hydroxide.

The third solvent is DMSO, DMF, dichloroethane or tetrachloroethane.

The first precipitant is ethanol, methanol, n-hexane, n-pentane or n-heptane.

The fourth solvent is toluene, tetrahydrofuran, chloroform, tetrachloroethane or dichloroethane.

The initiator is ABVN, AIBN, BPO, DTBP or TBCP.

The second precipitation agent is ethanol, methanol, n-hexane, n-pentane or n-heptane.

The above is only a preferred embodiment of the present invention, so the scope of the present invention cannot be limited accordingly, that is, equivalent changes and modifications made according to the patent scope of the present invention and the content of the specification should still be covered by the present invention In the range.

Claims (9)

1. A preparation method of phosphorus-nitrogen synergistic flame-retardant epoxy polymer, characterized in that: its molecular weight is 7000～100000g/mol, and its structural formula is as follows: Wherein, R1 is methyl, R2 and _R3 are H or methyl; X is _a benzene ring; x _: y:z=10～50:10～30:50～10, Including the following steps: (1) React 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, p-aminophenol and paraformaldehyde in the first solvent at 30-80°C for 4-8 hours , the product is washed with methanol to obtain a phenolic intermediate, and the phenolic intermediate is reacted with methacryloyl chloride or acryloyl chloride in the presence of a second solvent and an acid-binding agent at 0-50°C for 4-8 hours, and filtered Remove the acid-binding agent salt, and then purify the crude product by washing, rotary evaporation and drying to obtain the first polymer monomer MAdiDOPO; The molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, p-aminophenol and paraformaldehyde is 1:2.0～3.0:2.0～2.5, and the phenols The molar ratio of intermediate, methacryloyl chloride or acryloyl chloride, and acid-binding agent is 1:1.5～2.0:1.2～2.0; (2) Dissolve 2-amino-4-hydroxy-6-methylisocytosine completely in the third solvent, then heat to 90-170°C, stop heating, then quickly add methacrylic acid-2-isocyanate ethyl base ester, stirred for 1 to 60 minutes and then cooled with water to prevent the occurrence of polymerization reaction, precipitated with the first precipitant, and dried in vacuum to obtain a white powder, which is the second polymerized monomer; The molar ratio of 2-amino-4-hydroxyl-6-methylisocytosine to 2-isocyanatoethyl methacrylate is 1:0.8～2.0; (3) Dissolve the first polymerized monomer prepared in step (1), the second polymerized monomer prepared in step (2) and glycidyl (meth)acrylate in the fourth solvent, and add an initiator, and pass through After removing the oxygen in the solvent by bubbling nitrogen gas, stir and react at 45-95°C for 12-48 hours. After the reaction, concentrate the reaction solution and precipitate with the second precipitant to obtain the phosphorus-nitrogen synergistic flame-retardant epoxy Polymer, wherein the ratio of the total number of moles of the first polymerized monomer, the second polymerized monomer and glycidyl (meth)acrylate to the molar number of the initiator is 100:0.2～3, and the above-mentioned first polymerized monomer, The molar ratio of the second polymerizable monomer to glycidyl (meth)acrylate is 10-60:10-30:10-60. 2. The preparation method according to claim 1, characterized in that: the first solvent is ethanol, methanol, tetrahydrofuran, acetone or acetonitrile, and the 9,10-dihydro-9-oxa-10-phospha The dosage ratio of phenanthrene-10-oxide to the first solvent is 1 g: 1-20 mL. 3. preparation method as claimed in claim 1 is characterized in that: described second solvent is toluene, ethyl acetate, tetrahydrofuran (THF), N, N-dimethylformamide, dichloromethane or dimethyl sulfoxide, The usage ratio of the methacryloyl chloride or acryloyl chloride to the second solvent is 1g:1-20mL. 4. The preparation method according to claim 1, characterized in that: the acid-binding agent is pyridine, triethylamine, sodium bicarbonate, sodium carbonate or sodium hydroxide. 5. The preparation method according to claim 1, characterized in that: the third solvent is DMSO, DMF, dichloroethane or tetrachloroethane. 6. The preparation method according to claim 1, characterized in that: the first precipitant is ethanol, methanol, n-hexane, n-pentane or n-heptane. 7. The preparation method according to claim 1, characterized in that: the fourth solvent is toluene, tetrahydrofuran, chloroform, tetrachloroethane or dichloroethane. 8. The preparation method according to claim 1, characterized in that: the initiator is ABVN, AIBN, BPO, DTBP or TBCP. 9. The preparation method according to claim 1, characterized in that: the second precipitation agent is ethanol, methanol, n-hexane, n-pentane or n-heptane.