Biomass-based high-heat-resistance low-dielectric flame-retardant material as well as preparation method and application thereof

Abstract

The invention discloses a biomass-based high-heat-resistance low-dielectric flame-retardant material and a preparation method and application thereof.The biomass-based high-heat-resistance low-dielectric flame-retardant material is biomass-based low-dielectric thermosetting resin, biomass is used as a raw material, groups containing benzocyclobutene, phosphorus, nitrogen and other elements are introduced, and the biomass-based high-heat-resistance low-dielectric flame-retardant material is prepared. The material is prepared through substitution reaction and thermocuring. Compared with a traditional biomass low-dielectric material, the biomass-based high-heat-resistance low-dielectric flame-retardant material has ultrahigh thermal stability, good transparency, hydrophobic property and dielectric property and excellent dimensional stability and flame retardance, conforms to the environmental protection concept of green sustainable development, and is a good product serving as a 5G electronic packaging base material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic functional materials, and particularly relates to a biomass-based high-heat-resistant low-dielectric flame-retardant material and a preparation method and application thereof. BACKGROUND

[0002] In recent years, with the rapid development of electronic devices towards high frequency, integration and miniaturization, the demand for high-performance materials is increasingly urgent; in the fields of communication, aerospace, etc., the materials need to have excellent heat resistance, low dielectric properties and reliable flame retardant properties at the same time, so as to guarantee safety and at the same time reduce signal transmission loss. For example, 5G communication technology and the coming 6G era use sub-6GHz and millimeter waves for signal transmission, which will generate greater dielectric loss, so higher requirements are put forward for the dielectric properties of electronic packaging materials. In order to reduce resistance-capacitance delay, high-frequency organic materials with low dielectric constant (low-k) and low dielectric loss (low-loss) have attracted widespread attention from researchers.

[0003] In the research of improving the flame retardant properties of materials, most materials need to add a large amount of halogen-based flame retardant to meet the fireproofing requirements, which has environmental pollution and health risks, and is easy to cause physical and chemical compatibility problems. Adding flame retardants by physical blending is easy to cause problems such as poor interfacial compatibility and low flame retardant efficiency, while the chemical modification strategy may damage the intrinsic properties of the material.

[0004] Benzocyclobutene resin (BCB) does not need to add any curing agent during the curing process and does not release small molecules, at the same time, it is widely concerned due to its unique electrical insulation, low hygroscopicity and thermal stability, and is regarded as an ideal low-dielectric material. However, its molecular structure lacks flame-retardant elements, and the raw materials rely on petroleum-based monomers, which is contradictory to the concept of sustainable development. In the prior art, although there are studies trying to compound biomass components with flame retardants, but often due to unreasonable molecular design, it is difficult to synergistically optimize the heat resistance, dielectric property and flame retardancy.

[0005] Therefore, it is particularly important to develop a technical route of benzocyclobutene resin with wide raw materials and good flame retardancy. SUMMARY

[0006] The purpose of the present application is to overcome the defects of the prior art and provide a biomass-based high-heat-resistant low-dielectric flame-retardant material and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a biomass-based flame-retardant resin monomer M1, the structural formula of which is shown in the following formula:

[0009]

[0010] wherein Q is a phosphorus-containing and / or nitrogen-containing group, R1, R2 are independently selected from one of hydrogen, hydroxyl, benzocyclobutenyl, substituted or unsubstituted C1-C 20 alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, substituted or unsubstituted phenyl.

[0011] As a preference, R1, R2 are not hydrogen at the same time.

[0012] As a preference, Q is one of is a connecting site.

[0013] In a second aspect, the present application provides a preparation method of the above-mentioned biomass-based flame-retardant resin monomer M1, comprising the following steps:

[0014] Under the protection of inert gas, compound A is mixed with compound M, and the mixture is heated at 60-70℃ for more than 24 hours to obtain monomer M1;

[0015] wherein the structural formula of compound A is the structural formula of compound M is: X is halogen, and R1, R2, Q are defined as described above.

[0016] Specifically, the biomass-based high-heat-resistant low-dielectric flame-retardant material comprises 55%-59% of biomass matrix, 37-38% of low-polarity group and 4%-8% of flame retardant in mass fraction, wherein the low-polarity group is a benzocyclobutenyl group, the biomass matrix is a structure other than the benzocyclobutenyl group, and the flame retardant is compound M.

[0017] As a preference, X is Cl.

[0018] As a preference, the molar ratio of compound A to compound M is 6-6.3:1.

[0019] As a preference, the reaction time is 30 hours.

[0020] As a preference, the inert gas is nitrogen.

[0021] In a third aspect, the present application provides a biomass-based high-heat-resistant low-dielectric flame-retardant material, which is obtained by drying monomer M1 and then curing to obtain the biomass-based high-heat-resistant low-dielectric flame-retardant material.

[0022] As a preference, the curing specifically comprises: heating to 120℃ for two hours, then heating to 210℃ for two hours, and finally heating to 270℃ for four hours.

[0023] In a fourth aspect, the present application provides a flame-retardant product prepared from the biomass-based high-heat-resistance low-dielectric flame-retardant material.

[0024] In a fifth aspect, the present application provides an application of the biomass-based high-heat-resistance low-dielectric flame-retardant material as a packaging material.

[0025] Preferably, the biomass-based high-heat-resistance low-dielectric flame-retardant material can be used as an electronic packaging substrate for 5G.

[0026] The present application has the following advantages:

[0027] 1. The biomass-based high-heat-resistance low-dielectric flame-retardant material provided by the present application uses renewable biomass as a substrate, which can solve the problem of energy crisis and meet the green chemical concept of sustainable development; the P and N halogen-free flame-retardant elements are introduced through the molecular structure design of the flame-retardant agent with reaction function, which overcomes the physical and chemical compatibility problem between the flame-retardant agent and the substrate, and also meets the environmental protection concept.

[0028] 2. The biomass-based high-heat-resistance low-dielectric flame-retardant material provided by the present application has breakthrough thermal stability, ultra-high glass transition temperature, and improved flame retardancy of the benzocyclobutene resin compared with traditional biomass low-dielectric materials; the benzocyclobutene group does not need to add an initiator during the curing process and will not release small molecules, so the preparation process is more simple and environmentally friendly.

[0029] In summary, the biomass-based high-heat-resistance low-dielectric flame-retardant material of the present application provides a reference value for the conversion of aromatic biomass to high-performance functional materials. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The appearance diagram of the biomass-based high-heat-resistance low-dielectric flame-retardant material prepared in Example 1 of the present application.

[0031] Figure 2 The DMA diagram of the biomass-based high-heat-resistance low-dielectric flame-retardant material prepared in Example 16 of the present application, wherein A is the test result of material P1, and B is the test result of material P2.

[0032] Figure 3 The test results of the fixed-frequency dielectric constant of P1 and P2 at room temperature 2GHz-14.2GHz, wherein the abscissa is the test frequency, and the ordinate is the dielectric constant.

[0033] Figure 4 The schematic diagram of the limiting oxygen index (LOI) combustion of the biomass-based high-heat-resistance low-dielectric flame-retardant material prepared in Example 16 of the present application. DETAILED DESCRIPTION

[0034] The technical solutions of the present application are further described and explained in the following with reference to the specific embodiments in conjunction with the accompanying drawings.

[0035] Example 1: Synthesis of monomer M1

[0036]

[0037] (1) A three-necked flask was added with 0.73 g of sodium hydroxide, and after three times of air replacement, 2 g of isoeugenol dissolved in 30 mL of DMF was added into the system, and heated to reflux for five hours.

[0038] (2) After cooling to room temperature, 0.023 g of cuprous iodide and 0.015 g of 1-butylimidazole were added, and stirred for 30 minutes.

[0039] (3) 2.67 g of 4-bromobenzocyclobutene was added dropwise, and after the dropwise addition was completed, the oil bath was heated to 120°C for 24 hours.

[0040] (4) After concentration by suction filtration, column chromatography was performed with petroleum ether: ethyl acetate = 5:1 to purify the compound A.

[0041] (5) A three-necked flask was added with 0.7 g of sodium hydroxide and 0.03 g of azobisisobutyronitrile, and after three times of air replacement, 45 mL of dioxane was added, and 4.4 g of compound A was added under nitrogen protection, and heated to reflux at 40°C for 3 hours.

[0042] (6) 1 g of hexachlorocyclotriphosphazene was dissolved in 10 mL of dioxane, and was added dropwise into the above system under nitrogen protection, and after the dropwise addition was completed, the reaction was carried out at 70°C for 24 hours or more, and the reaction was monitored by TLC.

[0043] (7) After suction filtration, EA extraction was performed, and after drying with anhydrous sodium sulfate, concentration was performed.

[0044] (8) Column chromatography was performed with petroleum ether: ethyl acetate = 10:1 to purify the monomer M1, and the appearance thereof is shown in Figure 1 .

[0045] Example 2: Synthesis of monomer M1

[0046]

[0047] (1) A three-necked flask was added with 0.73 g of sodium hydroxide, and after three times of air replacement, 2 g of isoeugenol dissolved in 30 mL of DMF was added into the system, and heated to reflux for five hours.

[0048] (2) After cooling to room temperature, 0.023 g of cuprous iodide and 0.015 g of 1-butylimidazole were added, and stirred for 30 minutes.

[0049] (3) 2.67 g of 4-bromobenzocyclobutene was added dropwise, and after the dropwise addition was completed, the oil bath was heated to 120°C for 24 hours.

[0050] (4) After filtration and concentration, compound A was obtained by column chromatography with petroleum ether: ethyl acetate = 5: 1.

[0051] (5) Sodium hydride 0.67 g and azobisisobutyronitrile 0.027 g were added into a three-necked flask, which was degassed three times, and then 40 mL of dioxane was added. Under nitrogen protection, 4.2 g of compound A was added, and the mixture was heated to reflux at 40°C for 3 hours.

[0052] (6) 1 g of cyanuric chloride was dissolved in 10 mL of dioxane, and then added dropwise into the above system under nitrogen protection. After the dropwise addition was completed, the mixture was reacted at 60°C for 24 hours or more, and the reaction was monitored by TLC.

[0053] (7) After filtration, EA was used for extraction, and then the mixture was dried over anhydrous sodium sulfate and concentrated.

[0054] (8) The monomer M1 was obtained by column chromatography with petroleum ether: ethyl acetate = 20: 1.

[0055] Example 3: Synthesis of monomer M1

[0056]

[0057] (1) Sodium hydroxide 0.73 g was added into a three-necked flask, which was degassed three times, and then 2 g of isoeugenol dissolved in 30 mL of DMF was added into the system, and the mixture was heated to reflux for five hours.

[0058] (2) After cooling to room temperature, cuprous iodide 0.023 g and 1-butylimidazole 0.015 g were added, and the mixture was stirred for 30 minutes.

[0059] (3) 4-bromobenzocyclobutene 2.67 g was added dropwise, and the mixture was reacted at 120°C for 24 hours after the dropwise addition was completed.

[0060] (4) After filtration and concentration, compound A was obtained by column chromatography with petroleum ether: ethyl acetate = 5: 1.

[0061] (5) Sodium hydroxide 0.81 g and azobisisobutyronitrile 0.03 g were added into a three-necked flask, which was degassed three times, and then 45 mL of dioxane was added. Under nitrogen protection, 5.09 g of compound A was added, and the mixture was heated to reflux at 40°C for 3 hours.

[0062] (6) 1 g of phosphorus oxychloride was dissolved in 10 mL of dioxane, and then added dropwise into the above system under nitrogen protection. After the dropwise addition was completed, the mixture was reacted at 70°C for 24 hours or more, and the reaction was monitored by TLC.

[0063] (7) After filtration, EA was used for extraction, and then the mixture was dried over anhydrous sodium sulfate and concentrated.

[0064] (8) The monomer M1 was obtained by column chromatography with petroleum ether: ethyl acetate = 8: 1.

[0065] Example 4: Synthesis of monomer M1

[0066]

[0067] (1) A three-necked flask was charged with sodium hydroxide 0.73 g, and 2 g of eugenol dissolved in 30 mL of DMF was added into the system after three times of air exchange. The system was heated to reflux for five hours.

[0068] (2) After cooling to room temperature, cuprous iodide 0.023 g and 1-butylimidazole 0.015 g were added, and stirred for 30 minutes.

[0069] (3) 4-Bromobenzocyclobutene 2.67 g was added dropwise, and the reaction was carried out at 120°C for 24 hours after the oil bath was turned off.

[0070] (4) After extraction and concentration, compound A was obtained by column chromatography with petroleum ether: ethyl acetate = 5:1.

[0071] (5) A three-necked flask was charged with sodium hydroxide 0.7 g and azobisisobutyronitrile 0.03 g, and 45 mL of dioxane was added after three times of air exchange. 4.4 g of compound A was added under nitrogen protection, and the system was heated to reflux at 40°C for 3 hours.

[0072] (6) 1 g of hexachlorocyclotriphosphazene was dissolved in 10 mL of dioxane, and was added dropwise into the above system under nitrogen protection. The reaction was carried out at 70°C for 24 hours or more after the dropwise addition was completed, and the reaction was monitored by TLC.

[0073] (7) After extraction and concentration, the product was dried with anhydrous sodium sulfate.

[0074] (8) The product was obtained by column chromatography with petroleum ether: ethyl acetate = 10:1.

[0075] Example 5: Synthesis of monomer M1

[0076]

[0077] (1) A three-necked flask was charged with sodium hydroxide 0.73 g, and 2 g of eugenol dissolved in 30 mL of DMF was added into the system after three times of air exchange. The system was heated to reflux for five hours.

[0078] (2) After cooling to room temperature, cuprous iodide 0.023 g and 1-butylimidazole 0.015 g were added, and stirred for 30 minutes.

[0079] (3) 4-Bromobenzocyclobutene 2.67 g was added dropwise, and the reaction was carried out at 120°C for 24 hours after the oil bath was turned off.

[0080] (4) After extraction and concentration, compound A was obtained by column chromatography with petroleum ether: ethyl acetate = 5:1.

[0081] (5) Three neck flask added sodium hydride 0.67g, azobisisobutyronitrile 0.027g, after three times of air exchange, added dioxane 40ml, under nitrogen protection, added 4.2g compound A, heated to reflux at 40℃ for 3 hours.

[0082] (6) 1g cyanuric chloride was dissolved in 10ml dioxane, added dropwise to the above system under nitrogen protection, after dropwise addition, reacted at 60℃ for 24 hours or more, TLC was used to monitor the reaction.

[0083] (7) After suction filtration, EA was used for extraction, dried over anhydrous sodium sulfate, and then concentrated.

[0084] (8) Petroleum ether: ethyl acetate = 20:1 column chromatography was used to purify to obtain monomer M1.

[0085] Example 6: Synthesis of monomer M1

[0086]

[0087] (1) Three neck flask added sodium hydroxide 0.73g, after three times of air exchange, 2g eugenol dissolved in 30ml DMF was added to the system, heated to reflux for five hours.

[0088] (2) After cooling to room temperature, 0.023g cuprous iodide and 0.015g 1-butylimidazole were added, and stirred for 30 minutes.

[0089] (3) 2.67g 4-bromobenzocyclobutene was added dropwise, and after dropwise addition, the oil bath was reacted at 120℃ for 24 hours.

[0090] (4) After suction filtration and concentration, petroleum ether: ethyl acetate = 5:1 column chromatography was used to purify to obtain compound A.

[0091] (5) Three neck flask added sodium hydroxide 0.81g, azobisisobutyronitrile 0.03g, after three times of air exchange, added dioxane 45ml, under nitrogen protection, added 5.09g compound A, heated to reflux at 40℃ for 3 hours.

[0092] (6) 1g phosphorus oxychloride was dissolved in 10ml dioxane, added dropwise to the above system under nitrogen protection, after dropwise addition, reacted at 70℃ for 24 hours or more, TLC was used to monitor the reaction.

[0093] (7) After suction filtration, EA was used for extraction, dried over anhydrous sodium sulfate, and then concentrated.

[0094] (8) Petroleum ether: ethyl acetate = 8:1 column chromatography was used to purify to obtain monomer M1.

[0095] Example 7: Synthesis of monomer M1

[0096]

[0097] (1) A three-necked flask was charged with sodium hydroxide 0.72 g, and after three times of air exchange, 2 g of 2-methoxy-4-propylphenol dissolved in 30 mL of DMF was added to the system, and heated to reflux for five hours.

[0098] (2) After cooling to room temperature, cuprous iodide 0.022 g and 1-butylimidazole 0.014 g were added, and stirred for 30 minutes.

[0099] (3) 4-bromobenzocyclobutene 2.64 g was added dropwise, and after the dropwise addition was completed, the oil bath was heated to 120°C and reacted for 24 hours.

[0100] (4) After concentration by suction filtration, column chromatography was performed using petroleum ether: ethyl acetate = 5:1 to purify compound A.

[0101] (5) A three-necked flask was charged with sodium hydroxide 0.7 g, azobisisobutyronitrile 0.04 g, and after three times of air exchange, 45 mL of dioxane was added, and 4.46 g of compound A was added under nitrogen protection, and heated to reflux at 40°C for 3 hours.

[0102] (6) 1 g of hexachlorocyclotriphosphazene was dissolved in 10 mL of dioxane, and was added dropwise to the above system under nitrogen protection, and after the dropwise addition was completed, the reaction was carried out at 70°C for 24 hours or more, and the reaction was monitored by TLC.

[0103] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, concentration was performed.

[0104] (8) Column chromatography was performed using petroleum ether: ethyl acetate = 10:1 to purify monomer M1.

[0105] Example 8: Synthesis of monomer M1

[0106]

[0107] (1) A three-necked flask was charged with sodium hydroxide 0.72 g, and after three times of air exchange, 2 g of 2-methoxy-4-propylphenol dissolved in 30 mL of DMF was added to the system, and heated to reflux for five hours.

[0108] (2) After cooling to room temperature, cuprous iodide 0.022 g and 1-butylimidazole 0.014 g were added, and stirred for 30 minutes.

[0109] (3) 4-bromobenzocyclobutene 2.64 g was added dropwise, and after the dropwise addition was completed, the oil bath was heated to 120°C and reacted for 24 hours.

[0110] (4) After concentration by suction filtration, column chromatography was performed using petroleum ether: ethyl acetate = 5:1 to purify compound A.

[0111] (5) Three neck flask added sodium hydride 0.68g, azobisisobutyronitrile 0.028g, after three times of air exchange, added dioxane 40ml, under nitrogen protection, added 2.88g compound A, heated to reflux at 40℃ for 3 hours.

[0112] (6) 1g of cyanuric chloride was dissolved in 10ml of dioxane, and was added dropwise to the above system under nitrogen protection, after dropping, the reaction was carried out at 60℃ for 24 hours or more, and the reaction was monitored by TLC.

[0113] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, it was concentrated.

[0114] (8) Petroleum ether: ethyl acetate = 20:1 column chromatography purification to obtain monomer M1.

[0115] Example 9: Synthesis of monomer M1

[0116]

[0117] (1) Three neck flask added sodium hydroxide 0.72g, after three times of air exchange, 2g of 2-methoxy-4-propylphenol dissolved in 30ml of DMF was added to the system, heated to reflux for five hours.

[0118] (2) After cooling to room temperature, 0.022g of cuprous iodide and 0.014g of 1-butylimidazole were added, and stirred for 30 minutes.

[0119] (3) 2.64g of 4-bromobenzocyclobutene was added dropwise, and after dropping, the reaction was carried out at 120℃ for 24 hours.

[0120] (4) After suction filtration and concentration, petroleum ether: ethyl acetate = 5:1 column chromatography purification to obtain compound A.

[0121] (5) Three neck flask added sodium hydroxide 0.83g, azobisisobutyronitrile 0.03g, after three times of air exchange, added dioxane 45ml, under nitrogen protection, added 5.30g compound A, heated to reflux at 40℃ for 3 hours.

[0122] (6) 1g of phosphorus oxychloride was dissolved in 10ml of dioxane, and was added dropwise to the above system under nitrogen protection, after dropping, the reaction was carried out at 70℃ for 24 hours or more, and the reaction was monitored by TLC.

[0123] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, it was concentrated.

[0124] (8) Petroleum ether: ethyl acetate = 8:1 column chromatography purification to obtain monomer M1.

[0125] Example 10: Synthesis of monomer M1

[0126]

[0127] (1) A three-necked flask was charged with 0.72 g of sodium hydroxide, and after three times of replacement of gas, 2 g of 2-methoxy-4-vinylphenol and 0.002 g of polymerization inhibitor 1,4-naphthoquinone dissolved in 30 mL of DMF were added to the system, and heated to reflux for five hours.

[0128] (2) After cooling to room temperature, 0.025 g of cuprous iodide and 0.016 g of 1-butylimidazole were added, and stirred for 30 minutes.

[0129] (3) 2.92 g of 4-bromobenzocyclobutene was added dropwise, and after the addition was completed, the reaction was carried out at 120°C for 24 hours.

[0130] (4) After concentration by suction filtration, compound A was purified by column chromatography with petroleum ether: ethyl acetate = 5:1.

[0131] (5) A three-necked flask was charged with 0.7 g of sodium hydroxide and 0.028 g of azobisisobutyronitrile, and after three times of replacement of gas, 45 mL of dioxane was added, and 2.63 g of compound A was added under nitrogen protection, and heated to reflux at 40°C for 3 hours.

[0132] (6) 1 g of hexachlorocyclotriphosphazene was dissolved in 10 mL of dioxane, and added dropwise to the above system under nitrogen protection, and after the addition was completed, the reaction was carried out at 70°C for 24 hours or more, and the reaction was monitored by TLC.

[0133] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, concentration was carried out.

[0134] (8) Column chromatography with petroleum ether: ethyl acetate = 10:1 was used to purify the monomer M1.

[0135] Example 11: Synthesis of monomer M1

[0136]

[0137] (1) A three-necked flask was charged with 0.72 g of sodium hydroxide, and after three times of replacement of gas, 2 g of 2-methoxy-4-vinylphenol and 0.002 g of polymerization inhibitor 1,4-naphthoquinone dissolved in 30 mL of DMF were added to the system, and heated to reflux for five hours.

[0138] (2) After cooling to room temperature, 0.025 g of cuprous iodide and 0.016 g of 1-butylimidazole were added, and stirred for 30 minutes.

[0139] (3) 2.92 g of 4-bromobenzocyclobutene was added dropwise, and after the addition was completed, the reaction was carried out at 120°C for 24 hours.

[0140] (4) After concentration by suction filtration, compound A was purified by column chromatography with petroleum ether: ethyl acetate = 5:1.

[0141] (5) A three neck flask was charged with sodium hydride 0.69 g, azobisisobutyronitrile 0.028 g, after three times of vacuum-nitrogen replacement, 40 mL of dioxane was added, 2.60 g of compound A was added under nitrogen protection, heated to reflux at 40°C for 3 hours.

[0142] (6) 1 g of cyanuric chloride was dissolved in 10 mL of dioxane, added dropwise into the above system under nitrogen protection, after dropping, reacted at 60°C for 24 hours or more, and the reaction was monitored by TLC.

[0143] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, it was concentrated.

[0144] (8) Petroleum ether: ethyl acetate = 20: 1 column chromatography purification to obtain monomer M1.

[0145] Example 12: Synthesis of monomer M1

[0146]

[0147] (1) A three neck flask was charged with sodium hydride 0.72 g, after three times of vacuum-nitrogen replacement, 30 mL of DMF was added, 2 g of 2-methoxy-4-vinyl phenol and 0.002 g of polymerization inhibitor 1,4-naphthoquinone were added to the system, and heated to reflux for five hours.

[0148] (2) After cooling to room temperature, 0.025 g of cuprous iodide and 0.016 g of 1-butylimidazole were added, and stirred for 30 minutes.

[0149] (3) 2.92 g of 4-bromobenzocyclobutene was added dropwise, and after dropping, the oil bath was reacted at 120°C for 24 hours.

[0150] (4) After suction filtration and concentration, petroleum ether: ethyl acetate = 5: 1 column chromatography purification to obtain compound A.

[0151] (5) A three neck flask was charged with sodium hydride 0.83 g, azobisisobutyronitrile 0.03 g, after three times of vacuum-nitrogen replacement, 45 mL of dioxane was added, 3.13 g of compound A was added under nitrogen protection, heated to reflux at 40°C for 3 hours.

[0152] (6) 1 g of phosphorus oxychloride was dissolved in 10 mL of dioxane, added dropwise into the above system under nitrogen protection, after dropping, reacted at 70°C for 24 hours or more, and the reaction was monitored by TLC.

[0153] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, it was concentrated.

[0154] (8) Petroleum ether: ethyl acetate = 8: 1 column chromatography purification to obtain monomer M1.

[0155] Example 13: Synthesis of monomer M1

[0156]

[0157] (1) A three-necked flask was charged with sodium hydroxide 0.72 g, and 2 g of 2-methoxy-5-propylphenol dissolved in 30 mL of DMF was added to the system after three times of air replacement, and heated to reflux for five hours.

[0158] (2) After cooling to room temperature, cuprous iodide 0.022 g and 1-butylimidazole 0.014 g were added, and stirred for 30 minutes.

[0159] (3) 4-bromobenzocyclobutene 2.64 g was added dropwise, and after the dripping was completed, the oil bath was heated to 120°C and reacted for 24 hours.

[0160] (4) After concentration by suction filtration, column chromatography was performed using petroleum ether: ethyl acetate = 5:1, and after simple P-R reaction, compound A was obtained.

[0161] (5) A three-necked flask was charged with sodium hydroxide 0.7 g and azobisisobutyronitrile 0.04 g, and after three times of air replacement, 45 mL of dioxane was added, and 4.46 g of compound A was added under nitrogen protection, and heated to reflux at 40°C for 3 hours.

[0162] (6) 1 g of hexachlorocyclotriphosphazene was dissolved in 10 mL of dioxane, and was added dropwise to the above system under nitrogen protection, and after the dripping was completed, the reaction was carried out at 70°C for 24 hours or more, and the reaction was monitored by TLC.

[0163] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, concentration was performed.

[0164] (8) Column chromatography was performed using petroleum ether: ethyl acetate = 10:1 to obtain monomer M1.

[0165] Example 14: Synthesis of monomer M1

[0166]

[0167] (1) A three-necked flask was charged with sodium hydroxide 0.72 g, and 2 g of 2-methoxy-5-propylphenol dissolved in 30 mL of DMF was added to the system after three times of air replacement, and heated to reflux for five hours.

[0168] (2) After cooling to room temperature, cuprous iodide 0.022 g and 1-butylimidazole 0.014 g were added, and stirred for 30 minutes.

[0169] (3) 4-bromobenzocyclobutene 2.64 g was added dropwise, and after the dripping was completed, the oil bath was heated to 120°C and reacted for 24 hours.

[0170] (4) After concentration by suction filtration, column chromatography was performed using petroleum ether: ethyl acetate = 5:1, and after simple P-R reaction, compound A was obtained.

[0171] (5) A three-necked flask was added sodium hydride 0.68 g, azobisisobutyronitrile 0.028 g, and dioxane 40 mL was added after three times of replacement of gas, and 2.88 g of compound A was added under nitrogen protection, and heated to reflux at 40°C for 3 hours.

[0172] (6) 1 g of cyanuric chloride was dissolved in 10 mL of dioxane, and was added dropwise to the above system under nitrogen protection, and after the dropwise addition was completed, the reaction was carried out at 60°C for 24 hours or more, and the reaction was monitored by TLC.

[0173] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, concentration was performed.

[0174] (8) Petroleum ether: ethyl acetate = 20:1 column chromatography was used for purification to obtain monomer M1.

[0175] Example 15: Synthesis of monomer M1

[0176]

[0177] (1) A three-necked flask was added sodium hydroxide 0.72 g, and 2 g of 2-methoxy-5-propyl phenol dissolved in 30 mL of DMF was added to the system after three times of replacement of gas, and heated to reflux for five hours.

[0178] (2) After cooling to room temperature, cuprous iodide 0.022 g and 1-butylimidazole 0.014 g were added, and stirred for 30 minutes.

[0179] (3) 4-bromobenzocyclobutene 2.64 g was added dropwise, and after the dropwise addition was completed, the reaction was carried out at 120°C for 24 hours.

[0180] (4) After suction filtration and concentration, petroleum ether: ethyl acetate = 5:1 column chromatography was used for purification, and then a simple P-R reaction was performed to obtain compound A.

[0181] (5) A three-necked flask was added sodium hydroxide 0.83 g, azobisisobutyronitrile 0.03 g, and dioxane 45 mL was added after three times of replacement of gas, and 5.30 g of compound A was added under nitrogen protection, and heated to reflux at 40°C for 3 hours.

[0182] (6) 1 g of phosphorus oxychloride was dissolved in 10 mL of dioxane, and was added dropwise to the above system under nitrogen protection, and after the dropwise addition was completed, the reaction was carried out at 70°C for 24 hours or more, and the reaction was monitored by TLC.

[0183] (7) After suction filtration, EA was used for extraction, and after drying with anhydrous sodium sulfate, concentration was performed.

[0184] (8) Petroleum ether: ethyl acetate = 8:1 column chromatography was used for purification to obtain monomer M1.

[0185] Example 16: Preparation of biomass-based high-heat-resistant low-dielectric flame-retardant material

[0186] The M1 obtained in Example 1 was injected into a polytetrafluoroethylene mold and dried in a vacuum oven (50°C, -0.1MPa) for 12 hours. Then, the polytetrafluoroethylene mold was placed in a box-type high-temperature curing oven. The curing temperature program was selected to hold at 120°C for two hours, at 210°C for two hours, and at 270°C for four hours to obtain the corresponding biomass-based high heat-resistant, low dielectric, and flame-retardant material P2.

[0187] For comparison, monomer A used in Example 1 was dried and cured using the same method as described above to obtain material P1.

[0188] Test Example 1

[0189] Dynamic thermodynamic analysis of P1 and P2: P1 and P2 were heated in an air atmosphere from room temperature to 400℃ or from room temperature to 500℃ at a heating rate of 5℃ / min.

[0190] The results are as follows Figure 2 As shown in the data, the storage modulus of P1 is 2.23 GPa, and the storage modulus of P2 is 2.62 GPa. The glass transition temperature (T) of P1... g The temperature of P2 is 210℃, while that of P2 reaches as high as 480℃, indicating that P2 has extremely high thermal stability and a lower T value than traditional biomass low dielectric materials. g This represents a breakthrough improvement; as a biomass-based thermosetting resin, its thermal stability is comparable to that of phthalonitrile resin (T...). g = Around 500℃).

[0191] Test Example 2

[0192] The dielectric constant and dielectric loss of P1 and P2 were tested at room temperature under constant frequency from 2GHz to 14.2GHz. The test results of the dielectric constant are as follows: Figure 3 As shown in Table 1, the test results for dielectric loss are presented.

[0193] Table 1. Dielectric loss test results for P1 and P2

[0194]

[0195] pass Figure 3 As shown in Table 1, the dielectric constant of P1 is between 2.688 and 2.651, and the dielectric loss is between 5.914 × 10⁻⁶, within the range of 2 GHz to 14.2 GHz. -3 -1.106×10 -2 Between; however, at the same frequency, P2 has significantly lower dielectric constant and dielectric loss than P1, with a dielectric constant between 2.608 and 2.551 and a dielectric loss between 1.371 × 10⁻⁶. -3 -1.663×10-3 between.

[0196] P2 exhibits high frequency and low loss dielectric loss at room temperature, while P1 exhibits high frequency and high loss. This indicates that the biomass-based high heat resistance and low dielectric resistance flame retardant material provided by this invention has good dielectric properties.

[0197] Test Example 3

[0198] Limiting oxygen index (LOI) tests were performed on P1 and P2, and the results are as follows: Figure 4 As shown.

[0199] (1) According to the test, the limiting oxygen index of P1 is 20.8, the limiting oxygen index of P2 reaches 33.2, self-extinguishes in 7 seconds, and the burning length is 1.5cm, which is within the self-extinguishing range.

[0200] (2) By Figure 4 It can be seen that P2 has better flame retardancy than P1, and P2 has reached the level of flame retardant (LOI>27 is flame retardant material).

[0201] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A biomass-based flame-retardant resin monomer M1, characterized in that, The structural formula of the monomer M1 is shown below: in: Q is a phosphorus- and / or nitrogen-containing group; R1 and R2 are independently selected from hydrogen, hydroxyl, benzocyclobutenyl, substituted or unsubstituted C1-C groups, respectively. 20 One of alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, or substituted or unsubstituted phenyl.

2. The biomass-based flame-retardant resin monomer M1 according to claim 1, characterized in that, Q is One of them, This is the connection site.

3. A method for preparing biomass-based flame-retardant resin monomer M1 as described in claim 1 or 2, characterized in that, The preparation method includes the following steps: Under inert gas protection, compound A and compound M were mixed and reacted in an oil bath at 60-70°C for more than 24 hours to obtain monomer M1. in: The structural formula of compound A is: Wherein R1 and R2 are defined as described in claim 1 or 2; The structural formula of compound M is: Where X is a halogen, and Q is defined as described in claim 1 or 2.

4. The preparation method according to claim 3, characterized in that, The molar ratio of compound A to compound M is 6 to 6.3:

1.

5. The preparation method according to claim 3, characterized in that, The reaction time is 30 hours.

6. The preparation method according to claim 3, characterized in that, The inert gas is nitrogen.

7. A biomass-based high heat-resistant, low dielectric constant flame-retardant material, characterized in that, It is obtained by drying and curing the monomer M1 as described in any one of claims 1 or 2.

8. The biomass-based high heat-resistant, low-dielectric-resistance flame-retardant material according to claim 8, characterized in that, The curing process specifically involves: heating to 120°C and holding for two hours, then heating to 210°C and holding for two hours, and finally heating to 270°C and holding for four hours.

9. A flame-retardant product, prepared using the biomass-based high heat-resistant and low dielectric flame-retardant material as described in claim 8.

10. The application of the biomass-based high heat-resistant, low dielectric, flame-retardant material as described in claim 8 as an encapsulation material.

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