CN102391403A - Flame-retardant polymer containing phosphorus and nitrogen and preparation method thereof - Google Patents

Abstract

The invention discloses a phosphorus-nitrogen-containing flame-retardant polymer, which includes a first polymerizable monomer, and the first polymerizable monomer is a monomer molecule having active double bonds and phosphorus-nitrogen flame-retardant elements at the same time, and also includes The second polymerizable monomer; the phosphorus-nitrogen-containing flame-retardant polymer is formed by homopolymerizing the first polymerizable monomer or by the first polymerizable monomer and the second polymerizable monomer Copolymerized. The phosphorus-nitrogen-containing flame-retardant polymer of the present invention can be used as a flame-retardant additive, and can also be used as an intrinsic flame-retardant polymer material. Compared with existing additive flame retardants, the polymer The matrix has better compatibility, good flame retardancy, little impact on the mechanical properties of the material matrix, and good flame retardancy.

Description

A kind of phosphorus nitrogen-containing flame-retardant polymer and preparation method thereof

technical field

The invention belongs to the field of polymer materials, and in particular relates to a phosphorus-nitrogen-containing flame-retardant polymer and a preparation method thereof.

Background technique

With the development of science and technology, many polymer materials with excellent properties, such as polystyrene (PS), polymethyl methacrylate, polypropylene, etc., have been widely used in electronics, automobiles, construction, toys, packaging and other industries middle. Since most polymer materials are composed of carbon and hydrogen elements, they are highly flammable. In recent years, major fire accidents caused by the ignition of polymer materials have been frequently reported. Therefore, most polymer materials must be treated with flame retardants in actual use to make them reach a certain level of flame retardant. At present, the most commonly used method is to solve the flammability problem of polymer materials by adding halogenated flame retardants, phosphorus-containing organic or inorganic compounds. However, these additive methods have many disadvantages. For example, the amount of flame retardant is usually large (generally up to 20-50wt%), which will lead to a decrease in the mechanical properties and transparency of the polymer material, and over time it will be damaged due to flame retardancy. The migration and loss of the agent will reduce or even lose the flame retardant effect.

A flame-retardant polystyrene composition reported by Chinese Patent Publication No. CN1966567A, melt-blending 100 parts of polystyrene resin, 8-25 parts of bromine-containing compound and 2-6 parts of antimony trioxide by weight, the resulting flame-retardant Polystyrene products have good flame retardancy, the flame retardancy level can reach FV-0 (GB/T4609-93), and the oxygen index can reach 28, which can be used in many harsh environments. A fire-retardant expandable polystyrene foam composition reported in Chinese Patent Publication No. CN101087818A, its flame-retardant component is a bromine-containing cyclic compound, and the flame-retardant has good flame-retardant properties. It avoids the disadvantage that other bromine-containing compounds cannot be completely dissolved in styrene, and can be fully dissolved in styrene monomer, so when producing polystyrene foam, it can ensure that the generated foam is uniform and stable in performance. Although the above two methods of improving the flame retardancy of polystyrene by adding bromine-containing compounds are effective, the bromine-containing compounds will generate toxic and corrosive gases when the polymer is burned, causing pollution to the environment and endangering human health. Does not meet environmental protection requirements.

Chinese Patent Publication No. CN101014650A reports a halogen-free flame-retardant polymer foam material, which can introduce a flame retardant and an organic foaming agent into the matrix polymer together during the melting of polystyrene, and the foam material used is mainly For expanded polystyrene, or polystyrene foam sheets or particles, the halogen-free flame retardant used is a phosphorus-containing cyclic compound. International patent WO2009037236 (A1) reports a flame-retardant polystyrene or modified polystyrene, the matrix of which is at least one of polystyrene and high-impact polystyrene, or a mixture of both, and its flame retardant Composed of expanded graphite, phosphorus-containing compounds and fluoropolymers; the mechanical properties and flame-retardant properties of the final product are greatly improved compared with the polymer matrix, which can better meet the actual production needs. Although the above two cases of flame retardant polystyrene adopt the currently relatively environmentally friendly halogen-free flame retardant method, and avoid the large-scale use of bromine-containing compounds by adding phosphorus-based flame retardants, most of the flame retardants used are still Small molecules, this kind of flame retardant products still have the disadvantage that the performance of the product will deteriorate due to the loss and migration of the flame retardant during use.

Chinese Patent Publication No. CN101906234A reports a flame-retardant polymethyl methacrylate composition, the flame retardant used in which is chlorine-containing phosphate. Although the resulting products have good flame retardancy and impact resistance, however, as halogen-containing flame retardants are gradually phased out, chlorine-containing flame retardants are no longer in line with the development direction of halogen-free flame-retardant products. Moreover, the small molecule liquid flame retardant mentioned in this invention has disadvantages such as unfavorable processing and leakage of liquid solution.

Contents of the invention

In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a phosphorus-nitrogen-containing flame-retardant polymer whose flame-retardant structure does not migrate or lose.

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

In order to realize the above-mentioned purpose of the invention, the present invention adopts the following technical solutions:

A phosphorus-nitrogen-containing flame-retardant polymer, which includes a first polymerizable monomer, and the first polymerizable monomer is a monomer molecule having an active double bond and a phosphorus-nitrogen flame-retardant element at the same time, and its molecular structure is as follows:

; The phosphorus-nitrogen-containing flame-retardant polymer is formed by the homopolymerization of the first polymerizable monomer, and its molecular structural formula is:

; Wherein, R ₃ is a H atom or a methyl group, n is an integer of 2 to 6, and R ₄ is a methyl group or an ethyl group.

Further, the second polymerizable monomer is also included, and the molecular structural formula of the second polymerizable monomer is:

; The phosphorus-nitrogen-containing flame-retardant polymer is formed by copolymerization of the first polymerizable monomer and the second polymerizable monomer, and its molecular structural formula is:

; wherein, m is an integer of 1 to 300, R ₁ and R ₃ are H atoms or methyl, R ₂ is phenyl or -COOCH ₃ ; n is an integer of 2 to 6, R ₄ is methyl or ethyl.

A method for preparing phosphorus-nitrogen-containing flame-retardant polymers, comprising the following steps:

Step 1) preparing the first polymerized monomer;

First, according to the reaction molar ratio, alcohol compounds containing amino groups and aldehyde compounds are dissolved in the first solvent, and the temperature is raised to 20-80°C. At this time, dimethyl phosphite or Diethyl phosphite is slowly added dropwise into the reaction system, keeping the reaction temperature constant. After the reaction is completed, the product is purified by rotary evaporation and washing to finally obtain a precursor. The molecular structure of the precursor is as follows:

, wherein, n is an integer of 2 to 6, and _R is methyl or ethyl; then, the precursor is taken out according to the reaction molar ratio and dissolved in the first solvent, and the acid-binding agent triethylamine is added, and When the temperature drops to -10-10°C, slowly add acryloyl chloride or methacryloyl chloride dropwise. After the reaction is completed, filter and wash with water to obtain the pure first polymerized monomer;

Step 2) Homopolymerize or free-radically copolymerize the first polymerizable monomer with the second polymerizable monomer by basic bulk polymerization, solution polymerization, suspension polymerization or emulsion polymerization under the trigger of an initiator to obtain Contains phosphorus and nitrogen containing flame retardant polymers.

Further, the structural formula of the amine-based alcohol compound can be expressed as HO(CH ₂ ) _x NH ₂ , where x is a natural number between 2 and 6, and the corresponding compounds are ethanolamine, 3-amino-1- Propanol, 4-amino-1-butanol, 5-amino-1-pentanol and 6-amino-1-hexanol.

Further, the aldehyde compound is formaldehyde solution or paraformaldehyde.

Further, the first solvent is tetrahydrofuran, dichloromethane, ether, chloroform, methanol or ethanol.

Further, the specific steps of the free radical bulk polymerization method are: stirring 5-100% of the first polymerized monomer and 95-0% of the second polymerized monomer according to the total mass of the monomers until uniform to form a stable monomer body dispersion; add 0.02-3% oil-soluble free radical initiator relative to the total mass of the monomer, and after heating to the initiation temperature of 50-100°C, the polymerization reaction starts; when the conversion rate of the monomer is below 30%, Polymerize the viscous mixture at 60-150°C until the reaction is complete.

Further, the specific steps of the free radical solution polymerization method are: stirring 5-100% of the first polymerized monomer and 95-0% of the second polymerized monomer according to the total mass of the monomers until uniform, adding to the second Stir in the solvent to form a stable monomer solution; add an oil-soluble free radical initiator, polymerize at 30-90°C until the reaction is complete; remove the second solvent to obtain a phosphorus-nitrogen-containing flame-retardant polymer.

Further, the specific steps of the free radical suspension polymerization method are: after stirring 1 to 7 times the deionized water and 0.05 to 5% of the total mass of the monomers evenly, add 5 to 5% of the total mass of the monomers 100% of the first polymerization monomer, 95-0% of the second polymerization, 0.02-4% of the oil-soluble free radical initiator; after stirring into a homogeneous solution, stir and polymerize at 30-100°C, and filter after the reaction is complete , washed, and dried to obtain a granular solid that is a phosphorus-nitrogen-containing flame-retardant polymer.

Further, the specific steps of the free radical emulsion polymerization method are: stirring deionized water 1 to 7 times the total mass of monomers, 0.1 to 5% emulsifier and 0.02 to 5% water-soluble free radical initiator After uniformity, add 5-100% of the first polymerized monomer and 95-0% of the second polymerized monomer according to the total mass of the monomers; stir and polymerize at 5-80°C, and after the reaction is completed, demulsify and separate the solid powder The product is phosphorus nitrogen polymer.

Further, the oil-soluble free radical initiator is: 1) peroxygen initiators, including dibenzoyl peroxide, diacyl peroxide, lauryl peroxide, ester peroxides, dicarbonate peroxide class, cumene hydroperoxide, dicumyl peroxide or di-tert-butyl peroxide; 2) azo initiators, including azobisisobutyronitrile, azobisisoheptylnitrile or azobisisoheptylnitrile Dimethyl butyrate; or 3) oil-soluble oxidation-reduction initiation system, wherein the oxidizing agent is selected from hydroperoxide, benzoyl peroxide, dialkyl peroxide or diacyl peroxide compound, wherein the reducing agent is selected from From tertiary amines, naphthenates, mercaptans or organometallic compounds, the oil-soluble oxidation-reduction initiator system can be a combination of any oxidizing agent and any reducing agent.

Further, the water-soluble free radical initiator is: 1) inorganic peroxygen initiators, including potassium persulfate, ammonium persulfate, hydroperoxide and hydrogen peroxide; 2) azo initiators, including 2 , 2′-Azobisisobutylamidine dihydrochloride, 2,2′-Azo[2-(2-imidazolin-2-yl)propane]dihydrochloride, 4,4′-Azo Bis(4-cyanovaleric acid) and azodiisopropyl imidazoline; or 3) a water-soluble oxidation-reduction system, wherein the oxidizing agent is selected from hydrogen peroxide, persulfate or hydroperoxide, and the reducing agent is selected from From Fe ²⁺ , Cu ⁺ , sodium sulfite, sodium bisulfite, sodium thiosulfate, alcohol, amine, oxalic acid or glucose, the water-soluble oxidation-reduction initiator system can be any oxidant and any combination of reducing agents.

Further, the dispersant is any one of the following dispersants or a mixture of several dispersants, including 1) a water-soluble organic polymer dispersant, selected from polyvinyl alcohol, polyacrylic acid, polymethacrylate, horse Anhydride-styrene copolymer, methyl cellulose, hydroxypropyl cellulose, gelatin or sodium alginate; 2) water-insoluble inorganic powder selected from magnesium carbonate, calcium carbonate, calcium phosphate or talcum powder.

Further, the emulsifier is any one of the following emulsifiers or a mixture of several emulsifiers, including R ₃ COONa, where R ₃ =C _11-17 , R ₄ SO ₃ Na, where R ₄ =C _{11 ~17} , sodium alkylarylsulfonate, rosin soap, ammonium salt, amino acid, ethylene oxide polymer or R ₅ -(OC ₂ H ₄ )n-OH, R ₅ CO-(OC ₂ H ₄ )n -OH, R ₅ -C ₆ H ₄ (OC ₂ H ₄ )n-OH, wherein R ₅ =C _10-16 .

The phosphorus-nitrogen-containing flame-retardant polymer of the present invention is prepared by the homopolymerization of the prepared first polymerized monomer, and can be used as a flame-retardant additive. Compared with the existing additive-type flame retardant, the homopolymer is compatible with The polymer matrix has better compatibility, good flame retardancy, and little impact on the mechanical properties of the material matrix; the phosphorus-nitrogen-containing flame-retardant polymer of the present invention can also be prepared by combining the prepared first polymerized monomer with the second It is prepared by copolymerization of polymerized monomers and can be used as a flame-retardant polymer material. Since the phosphorus-nitrogen-containing structure is connected to the polymer molecular chain through a covalent bond, it has better compatibility with the resin matrix and the flame-retardant structure does not migrate. , no loss; the production process of the four optional copolymerization methods is very mature and the sources of required raw materials are extensive, easy for industrial production; it has broad industrial application prospects.

The present invention will be described in further detail below in conjunction with specific examples.

Detailed ways

Example 1:

In a 250ml three-necked flask equipped with mechanical stirring and a constant pressure dropping funnel, add 12.2g (0.2mol) ethanolamine and 40ml tetrahydrofuran, stir at room temperature, and after 10 minutes, add 40.0g (0.4mol) formaldehyde solution (concentration 30%), stirred and heated up to 70°C, 44.0 g (0.40 mol) of dimethyl phosphite was added dropwise within 2 hours under continuous stirring, and the reaction was stopped after 10 hours of reaction. The tetrahydrofuran solvent was removed, the crude product was dissolved in 100 ml of chloroform, washed three times with 10 ml of 0.1 mol/L sodium hydroxide solution, dried and the chloroform was removed to obtain a light yellow transparent liquid. Then take 45.7g (0.15mol) of the light yellow liquid and 150ml of chloroform, put them into a 250ml four-necked flask equipped with mechanical stirring, then add 30.3g of triethylamine (0.30mol), and add 27.2g of triethylamine dropwise at -10°C. g (0.30mol) acryloyl chloride, reacted for 6 hours, then raised the temperature of the system to 5°C, continued the reaction for 10 hours, filtered under reduced pressure, removed triethylamine salt, and the filtrate was water, 0.1mol/L sodium hydroxide solution, Wash with saturated brine, dry and remove the solvent, and the obtained brown-yellow transparent liquid is the phosphorus-nitrogen-containing compound A used in the present invention, and the yield is 90%.

A monomer structure characterization:

FTIR (neat liquid, cm ^-1 ): 1724cm ^-1 (C=O), 1633cm ^-1 (C=C), 1261cm ^-1 (P=O), 1031cm ^-1 , (POC). ¹ H NMR (CDCl ₃ , δ, ppm), 6.47-6.43(d, 1H), 6.18-6.11(dd, 1H), 5.88-5.86(d, 1H), 4.32-4.29(t, 2H), 3.83-3.79(d, 12H ), 3.29-3.26(d, 4H), 3.20-3.15(t, 2H).

Example 2:

In a 250ml three-necked flask equipped with mechanical stirring and a constant pressure dropping funnel, add 12.2g (0.2mol) ethanolamine and 40ml tetrahydrofuran, stir at room temperature, and after 10 minutes, add 40.0g (0.4mol) formaldehyde solution (concentration 30%), while adding stirring and controlling the temperature at 30° C., 44.0 g (0.40 mol) of dimethyl phosphite was added dropwise within 2 hours under continuous stirring, and the reaction was stopped after 24 hours. The tetrahydrofuran solvent was removed, the crude product was dissolved in 100 ml of chloroform, washed three times with 10 ml of 0.1 mol/L sodium hydroxide solution, dried and the chloroform was removed to obtain a light yellow transparent liquid. Then take 45.7g (0.15mol) of the light yellow liquid and 150ml of chloroform, put them into a 250ml four-necked flask equipped with mechanical stirring, then add 30.3g of triethylamine (0.30mol), and add 27.2g of triethylamine dropwise at -10°C. g (0.30mol) acryloyl chloride, reacted for 6 hours, then raised the temperature of the system to 5°C, continued the reaction for 10 hours, filtered under reduced pressure, removed triethylamine salt, and the filtrate was water, 0.1mol/L sodium hydroxide solution, Wash with saturated brine, dry and remove the solvent, and the obtained brownish-yellow transparent liquid is the phosphorus-nitrogen-containing compound A used in the present invention, and the yield is 70%.

A monomer structure characterization:

FTIR (neat liquid, cm ^-1 ): 1724cm ^-1 (C=O), 1633cm ^-1 (C=C), 1261cm ^-1 (P=O), 1031cm ^-1 , (POC).1H NMR (CDCl ₃ , δ, ppm), 6.47-6.43(d, 1H), 6.18-6.11(dd, 1H), 5.88-5.86(d, 1H), 4.32-4.29(t, 2H), 3.83-3.79(d, 12H) , 3.29-3.26(d, 4H), 3.20-3.15(t, 2H).

Example 3:

In a 250ml three-necked flask equipped with mechanical stirring and a constant pressure dropping funnel, add 12.2g (0.2mol) ethanolamine and 50ml methanol, add 12.0g (0.4mol) paraformaldehyde under stirring at room temperature, stir and heat up to 65 °C, under continuous stirring, 55.2 g (0.40 mol) of diethyl phosphite was slowly added dropwise within 2 hours, and the reaction was stopped after 12 hours of reaction. The methanol solvent was removed, the crude product was dissolved in 100 ml of chloroform, washed three times with 10 ml of 0.1 mol/L sodium hydroxide solution, dried and the chloroform was removed to obtain a light yellow transparent liquid. Then take 50.1g (0.15mol) of the light yellow liquid and 150ml of chloroform, put them into a 250ml four-necked flask equipped with mechanical stirring, then add 30.3g of triethylamine (0.30mol), and add 27.2g of triethylamine dropwise at -10°C. g (0.30mol) of acryloyl chloride, after the reaction is complete, filter under reduced pressure to remove the triethylamine salt, wash the filtrate with water, 0.1mol/L sodium hydroxide solution, and saturated brine, dry and remove the solvent, and the obtained brown The yellow transparent liquid is the phosphorus-nitrogen-containing compound A used in the present invention, and the yield is 87%.

A monomer structure characterization:

FTIR (neat liquid, cm ^-1 ): 1730cm ^-1 (C=O), 1635cm ^-1 (C=C), 1261cm ^-1 (P=O), 1031cm ^-1 , (POC).1H NMR (CDCl ₃ , δ, ppm), 6.47-6.43(d, 1H), 6.18-6.11(dd, 1H), 5.88-5.86(d, 1H), 4.32-4.29(t, 2H), 4.25-4.10(q, 8H) , 3.29-3.26(d, 4H), 3.20-3.15(t, 2H), 1.0-1.25(t, 12H).

Example 4:

In a 250ml three-necked flask equipped with mechanical stirring and constant pressure dropping funnel, add 23.4g (0.2mol) 6-amino-1-hexanol and 50ml tetrahydrofuran, stir at room temperature, after 10 minutes, add 12.0g (0.4 mol) paraformaldehyde, stirred and heated to 70°C, slowly added 44.0 g (0.40 mol) of dimethyl phosphite dropwise within 2 hours under continuous stirring, and stopped the reaction after 15 hours of reaction. The tetrahydrofuran solvent was removed, the crude product was dissolved in 100 ml of chloroform, washed three times with 10 ml of 0.1 mol/L sodium hydroxide solution, dried and removed of chloroform to obtain a dark yellow transparent liquid. Then take 54.2g (0.15mol) of the dark yellow liquid and 150ml of chloroform, put it into a 250ml four-necked flask equipped with mechanical stirring, then add 30.3g of triethylamine (0.30mol), and continue stirring at -10°C for 30min . Afterwards, take 27.2g (0.30mol) of acryloyl chloride, slowly drop it into the above reaction system, react for 6 hours, then raise the temperature of the system to 5°C, continue the reaction for 10 hours, filter under reduced pressure to remove the triethylamine salt, and the filtrate Wash with water, 0.1 mol/L sodium hydroxide solution, and saturated brine, dry and remove the solvent, and the obtained brownish-yellow transparent liquid is the phosphorus-nitrogen-containing compound A used in the present invention, and the yield is 85%.

FTIR (neat liquid, cm ^-1 ): 1730cm ^-1 (C=O), 1635cm ^-1 (C=C), 1261cm ^-1 (P=O), 1031cm ^-1 , (POC). ¹ H NMR (CDCl ₃ , δ, ppm), 6.47-6.43(d, 1H), 6.18-6.11(dd, 1H), 5.88-5.86(d, 1H), 4.02(t, 2H), 3.67(d, 12H), 3.06( d, 4H), 2.75 (tt, 2H), 1.65-1.21 (m, 8H).

Example 5:

In a 250ml three-necked flask equipped with mechanical stirring and constant pressure dropping funnel, add 23.4g (0.2mol) 6-amino-1-hexanol and 100ml chloroform, stir at room temperature, after 10 minutes, add 12.0g (0.4 mol) paraformaldehyde, stirred and heated up to 60° C., slowly added 55.2 g (0.40 mol) of diethyl phosphite dropwise within 2 hours under continuous stirring, and stopped the reaction after 18 hours of reaction. The crude product was washed three times with 10 ml of 0.1 mol/L sodium hydroxide solution, dried and removed from chloroform to obtain a brown transparent liquid. Then take 58.4g (0.15mol) of this liquid and 150ml of chloroform, put it into a 250ml four-necked flask equipped with mechanical stirring, then add 30.3g of triethylamine (0.30mol), and continue stirring at 0°C for 30min. Afterwards, take 27.2g (0.30mol) of acryloyl chloride, slowly drop it into the above reaction system, react for 10 hours, filter under reduced pressure, remove the triethylamine salt, the filtrate is water, 0.1mol/L sodium hydroxide solution, saturated salt After washing with water, drying and removing the solvent, the obtained brown yellow transparent liquid is the phosphorus-nitrogen-containing compound A used in the present invention, and the yield is 89%.

FTIR (neat liquid, cm ^-1 ): 1730cm ^-1 (C=O), 1635cm ^-1 (C=C), 1261cm ^-1 (P=O), 1031cm ^-1 , (POC). ¹ H NMR (CDCl ₃ , δ, ppm), 6.47-6.43(d, 1H), 6.18-6.11(dd, 1H), 5.88-5.86(d, 1H), 4.02(t, 2H), 4.25-4.10(q, 8H), 3.29-3.26 (d, 4H), 3.20-3.15 (t, 2H), 1.65-1.20 (m, 8H).

Embodiment 6:

In a 250ml three-necked flask equipped with mechanical stirring and constant pressure dropping funnel, add 23.4g (0.2mol) 6-amino-1-hexanol and 100ml chloroform, stir at room temperature, after 10 minutes, add 12.0g (0.4 mol) paraformaldehyde, stirred and heated to 60°C, slowly added 44.0 g (0.40 mol) of dimethyl phosphite dropwise within 2 hours under continuous stirring, and stopped the reaction after 18 hours of reaction. The crude product was washed three times with 10 ml of 0.1 mol/L sodium hydroxide solution, dried and removed from chloroform to obtain a brown transparent liquid. Then take 54.2g (0.15mol) of the liquid and 150ml of chloroform, put it into a 250ml four-neck flask equipped with mechanical stirring, then add 30.3g of triethylamine (0.30mol), and continue stirring at 0°C for 30min. Afterwards, take 31.2g (0.30mol) of methacryloyl chloride, slowly drop it into the above reaction system, react for 10 hours, filter under reduced pressure, remove the triethylamine salt, the filtrate is water respectively, 0.1mol/L sodium hydroxide solution, Wash with saturated brine, dry and remove the solvent, and the obtained brownish-yellow transparent liquid is the phosphorus-nitrogen-containing compound A used in the present invention, and the yield is 78%.

FTIR (neat liquid, cm ^-1 ): 1730cm ^-1 (C=O), 1635cm ^-1 (C=C), 1261cm ^-1 (P=O), 1031cm ^-1 , (POC). ¹ H NMR (CDCl ₃ , δ, ppm): 5.98-5.44(2m, 2H), 4.02(t, 2H), 3.65(12H), 3.02(d, 4H), 2.76(tt, 2H), 1.93(m, 3H), 1.66 -1.21 (m, 8H).

This shows that the polymerizable phosphorus-nitrogen-containing flame-retardant monomer of the present invention prepared by the above method has a structure of active double bonds and phosphorus-nitrogen flame-retardant elements at the same time.

Embodiment 7:

Take 10g of the phosphorus-nitrogen-containing flame retardant monomer A (accounting for 20% of the total monomer mass) prepared in Example 1 and dissolve it in 40g of styrene. After the two monomers are evenly dispersed, add the mixed monomer to dissolve 2.0g Sodium dodecylbenzenesulfonate in 250 g of deionized water was stirred at room temperature until the system was in a homogeneous state, and then 0.25 g (accounting for 0.5% of the total mass of the monomer) of potassium persulfate was added. The system was reacted at 60°C for 12 hours, and finally demulsified by saturated saline, filtered, washed with water and dried with methanol to obtain a white solid product, which was confirmed to be a copolymer of styrene and monomer A by infrared spectroscopy. The glass transition temperature of the obtained copolymer is 97°C, the microcalorimeter shows that its heat release capacity is 509J·g ^-1 ·K ^-1 , and the total heat release THR is 25.5kJ/g, while pure polystyrene under the same conditions The glass transition temperature is 103°C, the heat release capacity is 930J·g ^-1 ·K ^-1 , and the total heat release THR is 36.6KJ/g. This result shows that the introduction of flame retardant monomer A improves the polymer molecular chain flexibility and reduces the flammability of polystyrene.

FTIR (neat liquid, cm ^-1 ): 3030cm ^-1 (benzene ring hydrogen), 1728cm ^-1 (C=O), 1260cm ^-1 (P=O), 1040cm ^-1 , (POC).

Embodiment 8:

Take 10g of the flame retardant monomer A prepared in Example 3 (accounting for 20% of the total monomer mass) and dissolve it in 40g of styrene. After the two monomers are evenly dispersed, add 0.15g of azobisisobutylene required for initiation Nitrile, the temperature is raised to 90°C, and when the reaction conversion rate is about 20%, the temperature rise is stopped, and the mixture is transferred to another reactor, and the reaction is carried out at 60°C and 80°C for 20 hours respectively, and the reaction is stopped to obtain the flame retardant benzene Ethylene copolymer. The product was purified by dissolution and precipitation to obtain a white powder, which was confirmed to be a copolymer of styrene and monomer A by infrared spectroscopy. The glass transition temperature of the obtained copolymer is 92°C, the microcalorimeter shows that its heat release capacity is 549J·g ^-1 ·K ^-1 , and the total heat release THR is 26.8kJ/g, while pure polystyrene under the same conditions The glass transition temperature is 102°C, the heat release capacity is 935J·g ^-1 ·K ^-1 , and the total heat release THR is 36.6KJ/g. This result shows that the introduction of flame retardant monomer A improves the polymer molecular chain flexibility and reduces the flammability of polystyrene.

FTIR (neat liquid, cm ^-1 ): 3030cm ^-1 (benzene ring hydrogen), 1728cm ^-1 (C=O), 1260cm ^-1 (P=O), 1040cm ^-1 , (POC).

Embodiment 9:

Take 25g of the flame retardant monomer A prepared in Example 5 (accounting for 50% of the total monomer mass) and dissolve it in 25g of methyl methacrylate, and add 0.2g of dibenzoyl peroxide into a 250ml three-necked bottle , stirred, then added 250ml of deionized water and 0.3g of polyvinyl alcohol into the reactor, stirred evenly, and reacted at 95°C and 80°C for 2h and 20h respectively. After the reaction is finished, filter and wash the filter cake successively with a certain amount of deionized water and methanol. Finally, the filter cake was vacuum-dried to obtain a flame-retardant methyl methacrylate copolymer. The glass transition temperature of the obtained product was 85°C, and the microcalorimeter showed that its heat release capacity was 270J·g ^-1 ·K ^-1 . The heat release THR is 13.8kJ/g, while the glass transition temperature of pure polymethyl methacrylate under the same conditions is 106°C, the heat release capacity is 495J·g ^-1 ·K ^-1 , and the total heat release THR is 25.6 KJ/g, the result shows that the introduction of flame retardant monomer A improves the flexibility of the polymer molecular chain and reduces the flammability of polystyrene.

FTIR (neat liquid, cm ^-1 ): 1735cm ^-1 (C=O), 1725cm ^-1 (C=O), 1260cm ^-1 (P=O), 1040cm ^-1 , (POC).

Example 10:

Take 10g of the phosphorus-nitrogen-containing flame retardant monomer A prepared in Example 1, add the monomer into 50g of deionized water dissolved with 0.4g of sodium dodecylbenzenesulfonate, stir at room temperature until the system is in a homogeneous state, and then Add 0.05g (accounting for 0.5% of the total monomer mass) potassium persulfate. The system was reacted at 60°C for 12 hours, and finally demulsified by saturated saline, filtered, washed with water and methanol and dried to obtain a light yellow solid product, which was confirmed to be a polymer of monomer A by infrared spectroscopy. The microcalorimeter shows that its heat release capacity is 82J·g ^-1 ·K ^-1 , and the total heat release is 8.5kJ/g. This result shows that the polymer of flame retardant monomer A has extremely low heat release capacity and total heat release , indicating that it has good flame retardancy.

FTIR (neat liquid, cm ^-1 ): 2980cm ^-1 , 2965cm ^-1 (-CH ₃ ), 1728cm ^-1 (C=O), 1260cm ^-1 (P=O), 1040cm ^-1 , (POC).

Example 11:

Take 10g of the flame retardant monomer A prepared in Example 3, add 0.03g of azobisisobutyronitrile required for initiation, and raise the temperature to 90°C. When the reaction conversion rate is about 20%, stop the temperature rise, and transfer the mixture In another reactor, react at 60°C and 80°C for 24 hours, stop the reaction, and obtain the flame-retardant polymer of monomer A. The product was confirmed to be a homopolymer of monomer A by infrared spectroscopy. The microcalorimeter shows that its heat release capacity is 97J·g ^-1 ·K ^-1 , and the total heat release THR is 8.9kJ/g. This result shows that the polymer of flame retardant monomer A has extremely low heat release capacity and total The heat release shows that it has good flame retardancy.

FTIR (neat liquid, cm ^-1 ): 2980cm ^-1 , 2965cm ^-1 (-CH ₃ ), 1725cm ^-1 (C=O), 1263cm ^-1 (P=O), 1042cm ^-1 , (POC).

Example 12:

Take 10g of the flame retardant monomer A prepared in Example 5, add it into a 250ml three-necked bottle containing 0.04g of dibenzoyl peroxide, stir, then add 50ml of deionized water, 0.06g of polyvinyl alcohol into the reactor, stir After uniformity, react at 95°C and 80°C for 1h and 24h, respectively. After the reaction is finished, filter and wash the filter cake successively with a certain amount of deionized water n-hexane. Finally, the filter cake was vacuum-dried to obtain a flame-retardant homopolymer of monomer A. The microcalorimeter showed that its heat release capacity was 90J·g ^-1 ·K ^-1 , and the total heat release THR was 8.4kJ/g. It shows that the polymer of flame retardant monomer A has extremely low heat release capacity and total heat release, which shows that it has good flame retardant performance.

FTIR (neat liquid, cm ^-1 ): 2980cm ^-1 , 2965cm ^-1 (-CH ₃ ), 1733cm ^-1 (C=O), 1261cm ^-1 (P=O), 1038cm ^-1 , (POC).

Example 13:

Take 10g of the flame retardant monomer A prepared in Example 4, add it into a 50ml three-necked flask containing 0.03g of azobisisobutyronitrile, add 30g of 1,4-dioxane as a solvent, stir, and react at 65°C 48h. After the reaction was completed, the solution was concentrated, and the product was precipitated in n-hexane. The obtained product was a light yellow solid. The microcalorimeter showed that its heat release capacity was 83J·g ^-1 ·K ^-1 , and the total heat release THR was 8.6 kJ/g, the result shows that the polymer of flame retardant monomer A has extremely low heat release capacity and total heat release, indicating that it has good flame retardant performance.

FTIR (neat liquid, cm ^-1 ): 2988cm ^-1 , 2963cm ^-1 (-CH ₃ ), 1738cm ^-1 (C=O), 1264cm ^-1 (P=O), 1043cm ^-1 , (POC).

Example 14:

Get 10g of the phosphorus-nitrogen-containing flame-retardant monomer A prepared in Example 2, add the monomer into 30g of deionized water dissolved with 0.4g of sodium dodecylbenzenesulfonate, stir at room temperature until the system is in a homogeneous state, and then Add 0.05g (accounting for 0.5% of the total monomer mass) ammonium persulfate. The system was reacted at 65°C for 15 hours, and finally demulsified by saturated saline, filtered, washed with water and methanol and dried to obtain a light yellow solid product, which was confirmed to be a polymer of monomer A by infrared spectroscopy. The microcalorimeter shows that its heat release capacity is 78J·g ^-1 ·K ^-1 , and the total heat release is 8.0kJ/g. This result shows that the polymer of flame retardant monomer A has extremely low heat release capacity and total heat release , indicating that it has good flame retardancy.

FTIR (neat liquid, cm-1): 2984cm ^-1 , 2960cm ^-1 (-CH ₃ ), 1736cm ^-1 (C=O), 1261cm ^-1 (P=O), 1030cm ^-1 , (POC).

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and its purpose is to enable those of ordinary skill in the art to understand the content of the present invention and implement it accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the essence of the present invention shall fall within the protection scope of the present invention.

Claims (12)

1. A phosphorus-nitrogen-containing flame-retardant polymer, characterized in that it includes a first polymerizable monomer, and the first polymerizable monomer is a monomer molecule having an active double bond and a phosphorus-nitrogen flame-retardant element at the same time. The molecular structural formula is as follows:

; The phosphorus-nitrogen-containing flame-retardant polymer is formed by the homopolymerization of the first polymerizable monomer, and its molecular structural formula is:

; Wherein, R ₃ is a H atom or a methyl group, n is an integer of 2 to 6, and R ₄ is a methyl group or an ethyl group. 2. The phosphorus-nitrogen-containing flame-retardant polymer according to claim 1, further comprising a second polymerizable monomer, the molecular structural formula of the second polymerizable monomer is:

; The phosphorus-nitrogen-containing flame-retardant polymer is formed by copolymerization of the first polymerizable monomer and the second polymerizable monomer, and its molecular structural formula is:

; wherein, m is an integer of 1 to 300, R ₁ and R ₃ are H atoms or methyl, R ₂ is phenyl or -COOCH ₃ ; n is an integer of 2 to 6, R ₄ is methyl or ethyl. 3. A method for preparing the phosphorus-nitrogen-containing flame-retardant polymer according to claim 2, characterized in that, comprising the following steps: Step 1) preparing the first polymerized monomer; First, according to the reaction molar ratio, alcohol compounds containing amino groups and aldehyde compounds are dissolved in the first solvent, and the temperature is raised to 20-80°C. At this time, dimethyl phosphite or Diethyl phosphite is slowly added dropwise into the reaction system, keeping the reaction temperature constant. After the reaction is completed, the product is purified by rotary evaporation and washing to finally obtain a precursor. The molecular structure of the precursor is as follows:

, wherein, n is an integer of 2 to 6, and _R is methyl or ethyl; then, the precursor is taken out according to the reaction molar ratio and dissolved in the first solvent, and the acid-binding agent triethylamine is added, and When the temperature drops to -10-10°C, slowly add acryloyl chloride or methacryloyl chloride dropwise. After the reaction is completed, filter and wash with water to obtain the pure first polymerized monomer; Step 2) Homopolymerize the first polymerized monomer by free radical bulk polymerization, free radical solution polymerization, free radical suspension polymerization or free radical emulsion polymerization under the trigger of an initiator or with the second Free radical copolymerization of polymerized monomers to obtain phosphorus-nitrogen-containing flame-retardant polymers. 4. The method for preparing a phosphorus-nitrogen-containing flame-retardant polymer according to claim 3, characterized in that: the structural formula of the amino-based alcohol compound can be expressed as HO(CH ₂ ) _x NH ₂ , where x is Natural numbers between 2 and 6, the corresponding compounds are ethanolamine, 3-amino-1-propanol, 4-amino-1-butanol, 5-amino-1-pentanol and 6-amino-1-hexanol; The aldehyde compound is formaldehyde solution or paraformaldehyde; the first solvent is tetrahydrofuran, dichloromethane, ether, chloroform, methanol or ethanol. 5. The method for preparing phosphorus-nitrogen-containing flame-retardant polymers according to claim 3, characterized in that: the specific steps of the free radical bulk polymerization method are: the first polymerization of 5 to 100% of the total mass of monomers Stir the monomer and 95-0% of the second polymerized monomer until uniform to form a stable monomer dispersion; add 0.02-3% oil-soluble free radical initiator relative to the total mass of the monomer, heat to 50-100 After the initiation temperature of ℃, the polymerization reaction starts; when the monomer conversion rate is below 30%, the viscous mixture is polymerized at 60-150 ℃ until the reaction is complete. 6. The method for preparing a phosphorus-nitrogen-containing flame-retardant polymer according to claim 3, characterized in that: the specific steps of the free radical solution polymerization method are: the first polymerization of 5 to 100% of the total mass of monomers Stir the monomer and 95-0% of the second polymerization monomer until uniform, add it into the second solvent, stir to form a stable monomer solution; add an oil-soluble free radical initiator, and polymerize at 30-90°C until the reaction completely; the second solvent is removed to obtain a phosphorus-nitrogen-containing flame-retardant polymer. 7. The method for preparing a phosphorus-nitrogen-containing flame-retardant polymer according to claim 3, characterized in that, the specific steps of the free radical suspension polymerization method are: adding deionized water 1 to 7 times the total mass of the monomer After stirring evenly with 0.05-5% dispersant, add 5-100% of the first polymerization monomer, 95-0% of the second polymerization, and 0.02-4% of the oil-soluble free radical initiator according to the total mass of the monomer; After stirring into a homogeneous solution, stir and polymerize at 30-100°C. After the reaction is complete, filter, wash, and dry to obtain a granular solid that is a phosphorus-nitrogen-containing flame-retardant polymer. 8. The method for preparing a phosphorus-nitrogen-containing flame-retardant polymer according to claim 3, characterized in that: the specific steps of the radical emulsion polymerization method are: adding deionized water 1 to 7 times the total mass of the monomer , 0.1-5% emulsifier and 0.02-5% water-soluble free radical initiator are stirred evenly, then add 5-100% of the first polymerized monomer and 95-0% of the second polymerized monomer according to the total mass of the monomer solid; stir and polymerize at 5-80°C, and after the reaction is over, demulsify and separate the solid powder product, that is, the phosphorus-nitrogen polymer. 9. according to the method for claim 6 or 7 or 8 described preparation phosphorus-nitrogen flame retardant polymers, it is characterized in that, described oil-soluble free radical initiator is: 1) peroxygen initiator, comprises diperoxide Benzoyl, dicumyl peroxide, lauryl peroxide, ester peroxide, dicarbonate peroxide, cumene hydroperoxide, dicumyl peroxide, or di-tertbutyl peroxide; 2) Azo initiators, including azobisisobutyronitrile, azobisisoheptanonitrile or dimethyl azobisisobutyrate; or 3) oil-soluble oxidation-reduction initiation system, wherein the oxidizing agent is selected from hydroperoxide compounds, benzoyl peroxide, dialkyl peroxide or diacyl peroxide, wherein the reducing agent is selected from tertiary amines, naphthenates, mercaptans or organometallic compounds, and the oil-soluble oxidation-reduction initiator The agent system may be a combination of any oxidizing agent and any reducing agent. 10. The method for preparing phosphorus-nitrogen-containing flame-retardant polymers according to claim 8, characterized in that: the water-soluble free radical initiator is: 1) inorganic peroxygen initiators, including potassium persulfate, persulfuric acid Ammonium, hydroperoxide and hydrogen peroxide; 2) Azo initiators, including 2,2'-azobisisobutylamidine dihydrochloride, 2,2'-azo[2-(2- imidazolin-2-yl)propane]dihydrochloride, 4,4'-azobis(4-cyanovaleric acid) and azobisisopropylimidazoline; or 3) water-soluble oxidation-reduction systems, Wherein the oxidizing agent is selected from hydrogen peroxide, persulfate or hydroperoxide, and the reducing agent is selected from Fe2+, Cu+, sodium sulfite, sodium bisulfite, sodium thiosulfate, alcohol, amine, oxalic acid or glucose, and the water-soluble The active oxidation-reduction initiator system can be a combination of any oxidizing agent and any reducing agent. 11. The method for preparing a phosphorus-nitrogen-containing flame-retardant polymer according to claim 7, characterized in that: the dispersant is any of the following dispersants or a mixture of several dispersants, including 1) water-soluble organic high Molecular dispersant, selected from polyvinyl alcohol, polyacrylic acid, polymethacrylate, maleic anhydride-styrene copolymer, methyl cellulose, hydroxypropyl cellulose, gelatin or sodium alginate; 2) insoluble in Inorganic powder of water selected from magnesium carbonate, calcium carbonate, calcium phosphate or talc. 12. The method for preparing a phosphorus-nitrogen-containing flame-retardant polymer according to claim 8, characterized in that: the emulsifier is any one of the following emulsifiers or a mixture of several emulsifiers, including R ₃ COONa, wherein, R ₃ ＝C _11～17 , R ₄ SO ₃ Na, wherein, R ₄ ＝C _11～17 , sodium alkylarylsulfonate, rosin soap, ammonium salt, amino acid, ethylene oxide polymer or R ₅ - (OC ₂ H ₄ )n-OH, R ₅ CO-(OC ₂ H ₄ )n-OH, R ₅ -C ₆ H ₄ (OC ₂ H ₄ )n-OH, wherein R ₅ =C _10-16 .