Polymeric nitrogen and phosphorus flame retardant, preparation and application thereof
The polymeric nitrogen-phosphorus flame retardant prepared by multi-component reaction solves the problems of low flame retardant efficiency and poor compatibility of existing flame retardants, and realizes polylactic acid materials with high compatibility and excellent flame retardant properties, as well as good thermal stability and mechanical strength.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANTAI UNIV
- Filing Date
- 2026-03-23
- Publication Date
- 2026-06-05
Smart Images
Figure CN122145747A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer material modification, specifically relating to a polymer-type nitrogen-phosphorus flame retardant and its preparation and application. Background Technology
[0002] With continuous innovation in industrial technology and advancements in production processes, polymer materials are increasingly widely used in the national economy and daily life. However, traditional polymer materials, primarily composed of carbon chain structures, are highly flammable when exposed to open flames, potentially posing fire hazards and threats to public safety and property. Therefore, the development and application of polymer flame-retardant technology are of great significance for improving material safety and promoting safe production. Currently, adding flame retardants to polymer matrices has become a common and effective way to improve the fire resistance of materials. Although traditional halogenated flame retardants have high flame-retardant efficiency, they may release toxic and harmful substances during combustion, posing potential risks to the environment and human health. Therefore, they have been subject to strict restrictions and gradual phase-out under international regulations such as the EU RoHS Directive and the Stockholm Convention. To address this challenge, researchers have turned to developing environmentally friendly flame-retardant systems, such as phosphorus-based, nitrogen-based, and silicon-based halogen-free flame retardants. These systems offer better safety while effectively suppressing flames.
[0003] The compatibility of flame retardants with polymer matrices is a core challenge in the development of halogen-free flame retardant technology. In recent years, polymeric flame retardants have attracted widespread attention due to their advantages such as large molecular weight, good thermal stability, and low volatility. However, many existing polymeric flame retardants still face numerous challenges. For example, their flame retardant efficiency is often insufficient, requiring high addition levels to meet flame retardant standards. This can easily lead to poor compatibility between the flame retardant and the polymer, and also significantly damage the mechanical properties and processability of the material. Therefore, how to design and prepare novel polymeric flame retardants that combine excellent flame retardant efficiency with good compatibility has become a current research hotspot and challenge in this field.
[0004] This invention uses a multi-component reaction as a synthesis method to develop polymeric flame retardants with diverse structures, adjustable molecular weights, and high nitrogen and phosphorus content. These flame retardants have advantages such as high reaction efficiency, mild polymerization conditions, high atom economy, and good compatibility with polymer matrices, and have promising application prospects in the field of polymer material modification. Summary of the Invention
[0005] The technical problem to be solved by this invention is to provide a polymeric nitrogen-phosphorus flame retardant and its preparation and application, overcoming the shortcomings of existing flame retardants such as low flame retardant efficiency and poor compatibility. This polymeric nitrogen-phosphorus flame retardant has good compatibility and thermal stability. When used to prepare flame-retardant polylactic acid (PLA) products, the resulting PLA products are non-toxic and environmentally friendly, have excellent flame retardant properties, a high limiting oxygen index, and excellent mechanical strength.
[0006] The specific technical solution of this invention is as follows: a polymeric nitrogen-phosphorus flame retardant, with the following structural formula:
[0007]
[0008] Where n is an integer from 10 to 100; R 1 Selected from alkyl and phenyl groups with 1 to 15 carbon atoms; R 2 Selected from alkyl and phenyl groups with 1 to 15 carbon atoms; R 3 Selected from alkyl or phenyl groups with 1 to 12 carbon atoms.
[0009] A method for preparing a polymeric nitrogen-phosphorus flame retardant, specifically, involves using aldehydes and amines as starting materials, stirring in a reaction solvent to form an imine intermediate; then adding phosphite esters to carry out a polymerization reaction; after the reaction is complete, the crude product is dissolved in DMF, precipitated in ethanol, and the polymeric nitrogen-phosphorus flame retardant is obtained; the aldehyde is OHC-R. 1 -CHO, amine is NH2-R 2 -NH2, phosphite is (R 3 The reaction formula is: O)2P(O)H,
[0010]
[0011] Formula (1).
[0012] Preferably, aldehyde OHC-R 1 -CHO is selected from any one of the following (1-6); amine NH2-R 2 -NH2 is selected from any of the following (7-12); phosphite (R 3 O)2P(O)H is selected from any of the following (13-18):
[0013] .
[0014] Further, the reaction solvent is any one or more of methanol, dichloromethane, chloroform, 1,4-dioxane, N,N-dimethylformamide, dimethyl sulfoxide, or tetrahydrofuran, preferably a mixed solvent of 1,4-dioxane and dimethyl sulfoxide in a volume ratio of 3:2.
[0015] Furthermore, the aldehyde OHC-R 1 -CHO, amine NH2-R 2 -NH2, phosphite (R) 3 The molar ratio of O)2P(O)H is 1:1:(3~6).
[0016] Furthermore, the reaction time between the aldehyde and amine is 10–60 minutes, the polymerization time is 8–48 hours, and the polymerization temperature is 0–80°C. o C.
[0017] The application of a polymeric nitrogen-phosphorus flame retardant in flame-retardant polylactic acid (PLA), wherein the raw material ratio of the flame-retardant PLA is: 100 parts PLA and 0.5-8 parts polymeric nitrogen-phosphorus flame retardant.
[0018] The preparation method provided by this invention uses a multi-component reaction to prepare a polymer-type nitrogen-phosphorus flame retardant, which exhibits excellent flame-retardant properties. Compared with the prior art, the advantages of this invention are as follows:
[0019] 1. The polymer-type nitrogen-phosphorus flame retardant of the present invention is prepared by a multi-component reaction pathway. This process does not require the introduction of a catalyst and has advantages such as simple synthesis route, mild reaction conditions, and few by-products, making it easy to scale up production.
[0020] 2. The multi-component reaction used in this invention involves three polymerizable monomers. Its advantage lies in the fact that the resulting product structure exhibits significant aggregation, and nitrogen and phosphorus flame retardant elements can be introduced simultaneously. The product structure and molecular weight have a high degree of controllability.
[0021] 3. The polymer-type nitrogen-phosphorus flame retardant of the present invention has good compatibility with polylactic acid matrix. The limiting oxygen index (LOI) of polylactic acid using the flame retardant of the present invention can reach up to 31%, and the flame retardant level can reach UL-94 V-0 level, showing broad application prospects in the field of polymer material modification. Attached Figure Description
[0022] Figure 1 This is the GPC curve of the polymeric nitrogen-phosphorus flame retardant synthesized in Example 1 of this invention;
[0023] Figure 2 This is the 1H NMR spectrum of the polymeric nitrogen-phosphorus flame retardant synthesized in Example 1 of this invention;
[0024] Figure 3 This is the Fourier transform infrared spectrum of the polymeric nitrogen-phosphorus flame retardant synthesized in Example 1 of this invention;
[0025] Figure 4 This is the TGA curve of the polymeric nitrogen-phosphorus flame retardant synthesized in Example 1 of this invention;
[0026] Figure 5 These are the stretch curves of flame-retardant polylactic acid and pure polylactic acid synthesized in Examples 2 and 3 of this invention. Detailed Implementation
[0027] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.
[0028] Example 1:
[0029] Using terephthalaldehyde, p-phenylenediamine, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as raw materials, the reaction formula and experimental steps are as follows:
[0030]
[0031] The monomers terephthalaldehyde, p-phenylenediamine, and DOPO are commercially available; 0.1341 g (1.0 mmol) of terephthalaldehyde and 0.1081 g (1.0 mmol) of p-phenylenediamine were dissolved in 0.6 mL of 1,4-dioxane at 80 °C. o Stir at C for 10 minutes. Then add a mixed solution of DOPO (0.6480 g, 3.0 mmol) and dimethyl sulfoxide (DMSO, 0.4 mL). Continue stirring at 80°C. o The reaction was carried out at C for 12 hours. After the reaction was completed, the solution was cooled to room temperature, diluted with DMF, precipitated with ethanol, and dried to obtain polymeric nitrogen-phosphorus flame retardant P1 with a yield of 82%, a weight-average molecular weight of 38,700 g / mol, and a molecular weight distribution index of 1.4. The GPC curve is shown below. Figure 1 As shown.
[0032] The proton NMR spectrum of the polymeric nitrogen-phosphorus flame retardant P1 prepared in this embodiment is as follows: Figure 2 As shown. From Figure 2 As can be seen, the P1 spectrum shows aromatic proton signals for terephthalaldehyde, DOPO (8.45-6.85 ppm), and p-phenylenediamine (6.75-6.15 ppm). The infrared spectrum of the polymeric nitrogen-phosphorus flame retardant P1 prepared in this example is as follows: Figure 3 As shown, the P1 polymer at 1660 and 1510 cm⁻ 1 Characteristic peaks of the benzene ring series appeared at 1190 cm⁻. 1 The peaks at 1045 and 1090 cm⁻ show characteristic P=O peaks. 1 The peak at 3290 cm⁻ exhibits the characteristic POC peak. 1 The presence of the NH stretching vibration peak indicates a successful polymerization reaction. The TGA of the polymeric nitrogen-phosphorus flame retardant P1 prepared in this example is as follows: Figure 4 As shown, the thermal decomposition temperature at a 5% mass loss is 157°C. o C, the thermal decomposition temperature at which 50% mass loss occurs is 473°C. o C, 800 oAt temperature C, the carbon residue rate reaches 33%, demonstrating good thermal stability.
[0033] Example 2:
[0034] This embodiment describes a flame-retardant polylactic acid (PLA) prepared by the following method: 0.3 g of the polymeric nitrogen-phosphorus flame retardant P1 from Example 1 and 29.7 g of PLA were placed in a mixer and melt-blended at 180°C. The uniformly mixed material was transferred to a preheated flat vulcanizing mold, hot-pressed, and cooled under pressure to obtain the desired sample. The flame-retardant PLA prepared in this embodiment has a limiting oxygen index of 31% and a flame retardancy rating of V-0. Mechanical properties are as follows: Figure 5 As shown, the tensile strength is 25.0 MPa and the elongation at break is 2.0%.
[0035] Example 3:
[0036] This example is a comparative example of pure polylactic acid (PLA), prepared by the following method: 30 g of PLA was placed in a mixer and melted at 180°C; subsequently, the uniformly molten material was transferred to a preheated flat vulcanizing mold, and after hot pressing, pressure holding, and cooling, demolding was performed to obtain the desired sample. The pure PLA prepared in this example has a limiting oxygen index of 24% and no flame retardant rating. Mechanical properties are as follows. Figure 5 As shown, the tensile strength is 46.1 MPa and the elongation at break is 2.7%.
[0037] Example 4:
[0038] Using terephthalaldehyde, m-phenylenediamine, and DOPO as raw materials, the reaction formula and experimental steps are as follows:
[0039]
[0040] The monomers terephthalaldehyde, m-phenylenediamine, and DOPO are commercially available; 0.1341 g (1.0 mmol) of terephthalaldehyde and 0.1081 g (1.0 mmol) of m-phenylenediamine were dissolved in 0.6 mL of 1,4-dioxane at 80 °C. o Stir at C for 10 minutes. Then add a mixed solution of DOPO (0.6480 g, 3.0 mmol) and dimethyl sulfoxide (DMSO, 0.4 mL). Continue stirring at 80°C. o The reaction was carried out at C for 12 hours. After the reaction was completed, the solution was cooled to room temperature, diluted with DMF, precipitated with ethanol, and dried to obtain polymeric nitrogen-phosphorus flame retardant P2 with a yield of 80%, a weight-average molecular weight of 26,500 g / mol, and a molecular weight distribution index of 1.3.
[0041] Example 5:
[0042] Using glutaraldehyde, p-phenylenediamine, and DOPO as raw materials, the reaction formula and experimental steps are as follows:
[0043]
[0044] Glutaraldehyde, p-phenylenediamine, and DOPO are commercially available; dissolve glutaraldehyde (0.1001 g, 1.0 mmol) and p-phenylenediamine (0.1081 g, 1.0 mmol) in 0.6 mL of 1,4-dioxane at 80 °C. o Stir at C for 10 minutes. Then add a mixed solution of DOPO (0.6480 g, 3.0 mmol) and dimethyl sulfoxide (DMSO, 0.4 mL). Continue stirring at 80°C. o The reaction was carried out at C for 12 hours. After the reaction was completed, the solution was cooled to room temperature, diluted with DMF, precipitated with ethanol, and dried to obtain polymeric nitrogen-phosphorus flame retardant P3 with a yield of 75%, a weight-average molecular weight of 19800 g / mol, and a molecular weight distribution index of 1.4.
[0045] Example 6:
[0046] Using terephthalaldehyde, pentamethylenediamine, and DOPO as raw materials, the reaction formula and experimental steps are as follows:
[0047]
[0048] The monomers terephthalaldehyde, pentanediamine, and DOPO are commercially available; dissolve terephthalaldehyde (0.1341 g, 1.0 mmol) and pentanediamine (0.1022 g, 1.0 mmol) in 0.6 mL of 1,4-dioxane at 80 °C. o Stir at C for 10 minutes. Then add a mixed solution of DOPO (0.6480 g, 3.0 mmol) and dimethyl sulfoxide (DMSO, 0.4 mL). Continue stirring at 80°C. o The reaction was carried out at C for 12 hours. After the reaction was completed, the solution was cooled to room temperature, diluted with DMF, precipitated with ethanol, and dried to obtain polymeric nitrogen-phosphorus flame retardant P4 with a yield of 78%, a weight-average molecular weight of 22400 g / mol, and a molecular weight distribution index of 1.2.
[0049] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.
Claims
1. A polymeric nitrogen-phosphorus flame retardant, characterized in that, It has the following structure: ； Where n is an integer from 10 to 100; R 1 Selected from alkyl and phenyl groups with 1 to 15 carbon atoms; R 2 Selected from alkyl and phenyl groups with 1 to 15 carbon atoms; R 3 Selected from alkyl or phenyl groups with 1 to 12 carbon atoms.
2. The method for preparing the polymeric nitrogen-phosphorus flame retardant according to claim 1, characterized in that, Includes the following steps: Aldehyde and amine monomers were dissolved in a reaction solvent and reacted for a period of time. Then, phosphite was added, and the polymerization reaction continued. Subsequent processing yielded a polymeric nitrogen-phosphorus flame retardant; the aldehyde was OHC-R. 1 -CHO, amine is NH2-R 2 -NH2, phosphite is (R 3 O)2P(O)H, the reaction process is shown in equation (I): ； Formula (1).
3. The preparation method of the polymeric nitrogen-phosphorus flame retardant according to claim 2, characterized in that, Aldehyde OHC-R 1 -CHO is selected from any one of the following (1-6); amine NH2-R 2 -NH2 is selected from any of the following (7-12); phosphite (R 3 O)2P(O)H is selected from any of the following (13-18): 。 4. The preparation method of the polymeric nitrogen-phosphorus flame retardant according to claim 2, characterized in that, The reaction solvent is selected from any one or more of methanol, dichloromethane, chloroform, 1,4-dioxane, N,N-dimethylformamide, dimethyl sulfoxide, or tetrahydrofuran.
5. The method for preparing the polymeric nitrogen-phosphorus flame retardant according to claim 2, characterized in that, The aldehyde OHC-R 1 -CHO, amine NH2-R 2 -NH2, phosphite (R) 3 The molar ratio of O)2P(O)H is 1:1:(3~6).
6. The method for preparing the polymeric nitrogen-phosphorus flame retardant according to claim 2, characterized in that, The reaction time between aldehydes and amines is 10–60 minutes, the polymerization time is 8–48 hours, and the polymerization temperature is 0–80°C. o C.
7. The method for preparing the polymeric nitrogen-phosphorus flame retardant according to claim 2, characterized in that, The subsequent treatment refers to the process of diluting the polymer with N,N-dimethylformamide (DMF) after the polymerization reaction is complete, followed by precipitation in ethanol to obtain a polymeric nitrogen-phosphorus flame retardant.
8. The application of the polymeric nitrogen-phosphorus flame retardant according to claim 1 in flame-retardant polylactic acid, characterized in that, The proportions of the flame-retardant polylactic acid raw material are as follows: 100 parts polylactic acid and 0.5-8 parts polymeric nitrogen-phosphorus flame retardant.