WO2018095363A1

WO2018095363A1 - Benzoxazine polymer flame retardant containing fluorine and nitrogen and preparation method therefor

Info

Publication number: WO2018095363A1
Application number: PCT/CN2017/112585
Authority: WO
Inventors: 戴李宗; 王世成; 陈婷; 袁丛辉; 曾碧榕; 许一婷; 罗伟昂; 陈国荣; 何凯斌
Original assignee: 厦门大学
Priority date: 2016-11-23
Filing date: 2017-11-23
Publication date: 2018-05-31
Also published as: CN106750285A; CN106750285B

Abstract

Provided are a benzoxazine polymer flame retardant containing fluorine and nitrogen and a preparation method therefor. The flame retardant is represented by general formula (1), and in general formula (1), R1 is aa, R2 is bb or cc, and n = an integer of 1-100. The above-mentioned flame retardant can effectively improve the flame retardancy of an epoxy resin.

Description

[Invention name established by ISA according to Rule 37.2] Fluorine-containing nitrogen benzoxazine polymer type flame retardant and preparation method thereof

Technical field

The invention belongs to the technical field of synthesis of fluorine-containing nitrogen flame retardants, and relates to a preparation method of a novel fluorine-containing nitrogen benzoxazine polymer type flame retardant.

Background technique

With the rapid development of the polymer material industry, polymer materials are widely used in various industrial and civil fields. However, due to the flammability of polymer materials, how to improve the combustion properties of polymer materials has become a concern of people. The use of flame retardants is particularly important in the flame retardant of materials. With the promotion of the development of flame retardants in oil fields and forests, flame retardants have become the second largest polymer material additives.

Most of the traditional flame retardants are halogen-based flame retardants or derivatives of halogens and other flame retardants. These flame retardants will release toxic gases, pollute the environment, and cause secondary damage to the human body. Prohibited. Nitrogen, fluorine, phosphorus, silicon, etc. are also highly effective flame retardant elements. Flame retardants containing these elements are environmentally friendly and highly efficient, and are gradually favored by researchers and industry. Nitrogen-based flame retardants, due to their low toxicity and decomposition products, have catered to the trend of high-efficiency and low-toxicity of flame retardants. In recent years, they have been widely studied and applied at home and abroad; when hydrogen in polymers is When fluorine is substituted, the decomposition temperature of the material increases, and the decomposition product does not burn. Therefore, the flame retardant of fluorine nitrogen can have a good flame retardant effect, and the structure of the benzoxazine is similar to that of the phenolic resin, and has excellent heat resistance, insulation, corrosion and flame retardancy.

In the research work of epoxy resin flame retardancy, Liang Bing et al. (a halogen-free epoxy resin flame retardant and its preparation method, Chinese Patent Publication No. CN201510550549.2), pentaerythritol (PER) and phosphorus oxychloride (POCl3) reacts under certain conditions to form the intermediate pentaerythritol diphosphate diphosphonyl chloride (SPDPC), and the SPDPC and the glycidol are stirred and reacted under inert gas for a certain period of time, and the product is filtered, washed, steamed and dried. A halogen-free flame retardant is obtained which has excellent flame retardancy. Liu Wei District et al. (a phosphorus-containing silicon heat-resistant hybrid epoxy resin, Chinese patent, publication number CN100560632C) hydrolyzes an epoxy polyalkylsilane with water under the action of a catalyst in an organic solvent system, and then The phosphorus-containing active material is added to continue the reaction, and finally the organic solvent is removed to obtain a phosphorus-containing silicon heat-resistant hybrid epoxy resin, which has excellent mechanical properties, flame retardancy and heat resistance after curing.

The invention prepares a fluorine-containing nitrogen benzoxazine type polymer by Mannich condensation on the basis of molecular design, and is used for flame retardancy of epoxy resin. Polymer flame retardant has good compatibility with epoxy resin; benzene Due to its special structure, oxazine can be opened and crosslinked at high temperature, which can further improve the crosslinking degree of epoxy resin; the synergistic flame retardant effect of fluorine and nitrogen can effectively improve the flame retardant properties of epoxy resin, and at the same time, fluorine The introduction of elements also reduces the surface energy of the material and extends the properties of the material.

Summary of the invention

The object of the present invention is to provide a fluorine-containing nitrogen benzoxazine polymer type flame retardant for the disadvantages existing in the prior art, and to provide a method for preparing the polymer flame retardant. The nitrogen fluoride-containing flame retardant obtained by the invention is a polymer, and the structure thereof is similar to polybenzoxazine, and the flame retarding efficiency is high, and the preparation process is simple.

The fluorine-containing nitrogen benzoxazine polymer type flame retardant having a structural formula such as (I)

In formula (I), wherein R ₁ is

R ₂ is

n is from 1 to 100. For example, n=10/20/30/40/50/60/70/80/90.

The preparation method of the fluorine-containing nitrogen benzoxazine polymer type flame retardant, the specific steps are as follows:

Take a certain amount of paraformaldehyde, dihydric phenol, diamine and the first solvent in a single-mouth bottle, raise the temperature to 30-120 ° C, fill with nitrogen protection, react for 4 to 24 h, and then remove the solvent by suction filtration. The fluorine-containing nitrogen benzoxazine polymer was obtained after drying in a vacuum oven. Wherein, the ratio of the ratio of the paraformaldehyde, the dihydric phenol and the diamine to the molar ratio is paraformaldehyde: dihydric phenol: diamine = 1:1 to 10:1 to 10. Preferably, the ratio of the ratio of the paraformaldehyde, the dihydric phenol and the diamine to the molar ratio is paraformaldehyde: dihydric phenol: diamine = 1:1 to 8:1-8.

The synthetic route of the fluorine-containing nitrogen benzoxazine polymer type flame retardant is as follows:

The diphenol is

The diamine is H ₂ NCH ₂ CH ₂ NH ₂ ,

One of the above; the ratio of the paraformaldehyde, the dihydric phenol and the diamine to the molar ratio is paraformaldehyde: dihydric phenol: diamine = 1:1 to 8:1 to 8; One solvent is tetrahydrofuran, toluene, N,N-dimethylformamide.

Preferably, the vacuum drying is performed at a vacuum of -0.01 to 0.096 MPa, a treatment time of 18 to 30 hours, and a treatment temperature of 40 to 80 °C.

Compared with the prior art, it has the following advantages:

(1) The reaction raw materials are generally easy to obtain, the price is low, and the reaction conditions are mild, and can be obtained by Mannich condensation one-pot reaction, and the operation is simple.

(2) The novel fluorine-containing nitrogen benzoxazine polymer type flame retardant of the present invention has a controlled molecular weight, and the polymer flame retardant has good compatibility with the epoxy resin.

(3) Due to its special structure, benzoxazine is opened and crosslinked at high temperature, which can further improve the crosslinking degree of epoxy resin and improve the thermal stability and mechanical properties of epoxy resin.

(4) The synergistic flame retardant effect of fluorine and nitrogen can effectively improve the flame retardant properties of epoxy resin. At the same time, the introduction of fluorine can also reduce the surface energy of the material and expand the properties of the material.

DRAWINGS

Figure 1 is an infrared spectrum of the product obtained in Example 1.

2 is a nuclear magnetic resonance spectrum of the product obtained in Example 1.

The invention will now be further described with reference to the drawings and embodiments.

detailed description

The contents of the present invention will be specifically described below by way of an invention example:

Example 1:

Synthesis of nitrogen-containing fluorobenzoxazine polymer type flame retardant:

When preparing R1 in the structural formula (I)

R2 is

The process steps and conditions are as follows:

1 g of hexafluorobisphenol A, 0.366 g of paraformaldehyde and 0.708 g of p-phenylenediamine and the first solvent were placed in a single-mouth bottle, and the temperature was raised to 80 ° C, and the mixture was purged with nitrogen for 24 hours. After the reaction was completed, the solvent was removed by suction filtration. The fluorine-containing nitrogen benzoxazine polymer was obtained after drying at 60 ° C for 24 hours in a vacuum oven. The infrared spectrum of the fluorine-containing nitrogen benzoxazine polymer type flame retardant is shown in Fig. 1. 1168cm ^-1 characteristic absorption peaks CF _3, 1240cm ^-1 absorption peaks characteristic of CN, 1450cm ^-1 is -CH ₂ - absorption peak characteristic, 3280cm ^-1 is -NH ₂ - characteristic absorption peak. The nuclear magnetic resonance spectrum of the fluorine-containing nitrogen benzoxazine polymer type is shown in Fig. 2, and the characteristic peak of the corresponding group appears.

Example 2:

1 g of hexafluorobisphenol A, 0.366 g of paraformaldehyde and 0.708 g of p-phenylenediamine and the first solvent were placed in a single-mouth bottle, and the temperature was raised to 80 ° C, and the mixture was purged with nitrogen for 20 hours. After the reaction was completed, the solvent was removed by suction filtration. The fluorine-containing nitrogen benzoxazine polymer was obtained after drying at 80 ° C for 18 hours in a vacuum oven.

Example 3:

1 g of hexafluorobisphenol A, 0.366 g of paraformaldehyde and 0.708 g of p-phenylenediamine and the first solvent were placed in a single-mouth bottle, and the temperature was raised to 100 ° C, and the mixture was purged with nitrogen for 24 hours. After the reaction was completed, the solvent was removed by suction filtration. The fluorine-containing nitrogen benzoxazine polymer was obtained after drying at 40 ° C for 30 hours in a vacuum oven.

Example 4:

1 g of hexafluorobisphenol A, 0.366 g of paraformaldehyde and 0.708 g of p-phenylenediamine and the first solvent were placed in a single-mouth bottle, and the temperature was raised to 100 ° C, and the solution was purged with nitrogen for 20 hours. After the reaction was completed, the solvent was removed by suction filtration. The fluorine-containing nitrogen benzoxazine polymer was obtained after drying at 60 ° C for 24 hours in a vacuum oven.

Example 5

1 g of hexafluorobisphenol A, 0.714 g of paraformaldehyde and 2.574 g of p-phenylenediamine and the first solvent were placed in a single-mouth bottle, and the temperature was raised to 80 ° C, and the mixture was purged with nitrogen for 24 hours. After the reaction was completed, the solvent was removed by suction filtration. The fluorine-containing nitrogen benzoxazine polymer was obtained after drying at 60 ° C for 24 hours in a vacuum oven.

Example 6

1 g of hexafluorobisphenol A, 0.714 g of paraformaldehyde and 2.574 g of p-phenylenediamine and the first solvent were placed in a single-mouth bottle, and the temperature was raised to 100 ° C, and the mixture was purged with nitrogen for 20 h, and the solvent was removed by suction filtration. The fluorine-containing nitrogen benzoxazine polymer was obtained after drying at 60 ° C for 24 hours in a vacuum oven.

The above is only the preferred embodiment of the present invention, and thus the scope of the present invention is not limited thereto, and equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the specification should still be covered by the present invention. In the range.

Claims

A fluorine-containing nitrogen benzoxazine polymer type flame retardant characterized in that the flame retardant is a fluorine-containing nitrogen benzoxazine polymer type compound represented by the general formula (1):

In the formula (1), R 1 is
R 2 is
An integer of n=1-100.
The method for preparing a fluorine-containing nitrogen benzoxazine polymer type flame retardant according to claim 1, wherein the specific steps are as follows:

Take a certain amount of paraformaldehyde, dihydric phenol, diamine and the first solvent in a single-mouth bottle, raise the temperature to 30-120 ° C, fill with nitrogen protection, react for 4 to 24 h, and then remove the solvent by suction filtration. After drying in a vacuum drying oven, the fluorine-containing nitrogen benzoxazine polymer of the formula (1) is obtained, wherein the ratio of the paraformaldehyde, the dihydric phenol and the diamine to the molar ratio is paraformaldehyde: Dihydric phenol: diamine = 1:1 ~ 10: 1 ~ 10.
The method for preparing a fluorine-containing nitrogen benzoxazine polymer type flame retardant according to claim 2, wherein the paraform ratio of the paraformaldehyde, the dihydric phenol and the diamine is a paraformaldehyde : Dihydric phenol: Diamine = 1:1 to 8:1 to 8.
The method for preparing a fluorine-containing nitrogen benzoxazine polymer type flame retardant according to claim 2, wherein the first solvent is at least one of tetrahydrofuran, toluene and N,N-dimethylformamide. Kind.
The method for preparing a fluorine-containing nitrogen benzoxazine polymer type flame retardant according to claim 2, characterized in that the vacuum drying degree is -0.01 to 0.096 MPa, the reaction time is 18-30 hours, and the reaction temperature is 40. -80 ° C.