CN107868255A - The preparation method and applications of POSS DOPO triazine derivative flame retardants with self assembly humidification - Google Patents

Abstract

The invention discloses a preparation method and application of a POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect. The molecular structural formula of the flame retardant is as follows: where R is The invention improves the thermal stability and flame retardancy of the epoxy resin matrix on the basis of ensuring the mechanical properties of the matrix, and has the advantages of good flame retardant effect, wide application range and the like.

Description

Preparation of POSS-DOPO-triazine derivative flame retardant with enhanced self-assembly Method and its application

technical field

The invention belongs to the technical field of flame retardants, and in particular relates to a preparation method and application of a POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect.

Background technique

Epoxy resin has good physical and chemical properties, heat resistance, solvent resistance, excellent electrical insulation and mechanical properties, so it is widely used in electronic instruments, adhesives, construction and so on. With the increasing attention of epoxy resin, the requirements for its safety are gradually increasing. Epoxy resin is a three-dimensional network structure with high internal stress and surface energy, and is flammable. Therefore, it is necessary to ensure its mechanical properties on the basis of its flame retardancy modification.

Phosphorus, nitrogen, and silicon are all effective flame retardant elements. Among them, organophosphorus can promote the carbonization of polymers, and the carbon layer can protect the substrate from heat and oxygen during combustion, thereby improving flame retardancy and thermal stability. 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) has excellent flame retardancy, it has a super thermally stable P-O-C bond and O=P-O group protected by a benzene ring group, and DOPO is cheap and waterproof, and the O-P-H bond in DOPO makes it highly reactive, so that a series of derivatives can be synthesized to modify the polymer.

Nitrogen-containing groups can release non-combustible gas, dilute oxygen, absorb heat or take away heat to reduce the pyrolysis temperature when the burning surface decomposes, so as to achieve the effect of flame retardancy. Triazine-based polymers have been reported in many literatures because of their high nitrogen content and good char-forming effects. The triazine structure is not only a nitrogen source for flame retardancy, but also enhances thermal stability by providing a rigid structure. Meng Fanyi (a triazine-based macromolecular halogen-free flame-retardant char-forming agent compound, CN106009037A) prepared a triazine-based macromolecular flame-retardant char-forming agent by reacting triglycidyl isocyanurate and alcohol amine, which has char-forming properties. Anti-drip action.

Silicon-containing compounds promote the formation of an insulating protective carbon, a thermally stable carbon layer that protects the substrate and reduces the generation of flammable gas products. Wherein POSS is a nano-structure, cage-like, three-dimensional structure with a high content of silicon, which has excellent flame retardancy and can improve other properties of the polymer matrix. Dai Lizong (a phosphorus-containing silicon reactive macromolecular flame retardant and its preparation method and application, Chinese patent, publication number CN104262538A) is a combination of 4-methacrylamidoaniline, phosphorus-containing monomer and methacryloyl Oxypropyl heptaisobutyl POSS is prepared by free radical polymerization to obtain phosphorus-containing silicon reactive macromolecular flame retardant, which can be used in the preparation of flame-retardant epoxy resin.

At present, there are various phosphorus-based, nitrogen-based and silicon-based flame retardants, but the flame retardants of each element have some defects, such as a large amount added to the polymer, poor compatibility, and reduced matrix mechanical properties and other issues.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and provide a POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect.

Another object of the present invention is to provide the preparation method of the above-mentioned POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect.

Another object of the present invention is to provide a kind of preparation method based on the flame-retardant epoxy resin of above-mentioned POSS-DOPO-triazine derivative flame retardant.

Technical scheme of the present invention is as follows:

POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect, its molecular structural formula is as follows:

where R is

_R1 is

The specific synthesis steps of the above-mentioned POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect are as follows:

(1) Weigh cyanuric chloride and aminopropyl oligomeric silsesquioxane (POSS-NH ₂ ), respectively dissolve in the first organic solvent, dissolve and stir at -5～0°C to obtain the first solution and The second solution, the second solution is added dropwise in the first solution, while adding the first acid-binding agent to maintain the pH value of the material, when the ratio of cyanuric chloride and aminopropyl oligomeric silsesquioxane is 1: 1～1.2, the temperature is maintained at -5～10℃; when the ratio of cyanuric chloride and aminopropyl oligomeric silsesquioxane is 1:2～2.5, the reaction temperature rises slowly to room temperature, and the reaction 2～ 8h, then remove the first organic solvent and obtain an intermediate product after purification;

(2) The above-mentioned intermediate product and BisDOPO-OH (see CN104262398A) are dissolved in the second organic solvent respectively to obtain the third solution and the fourth solution respectively, and the molar ratio of the intermediate product and BisDOPO-OH is 1: 2～2.5 or 1:1~1.2, slowly drop the fourth solution into the third solution within 1h, stir at 60~80°C, add the second acid binding agent at the same time, the reaction time is 12~24h, and then use distilled water and acetonitrile Purify to obtain the POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect.

In a preferred embodiment of the present invention, in the step (1), the first organic solvent includes methylene chloride, chloroform, ether and tetrahydrofuran, and the first acid-binding agent includes aqueous sodium carbonate, aqueous sodium bicarbonate and carbonic acid calcium solution.

In a preferred embodiment of the present invention, the second organic solvent in the step (2) is a mixture of two of dichloromethane, dioxane and dimethyl sulfoxide at a volume ratio of 1:1, The second acid-binding agent includes triethylamine, ethylenediamine and isopropylamine.

In a preferred embodiment of the present invention, the purification in steps (1) and (2) includes precipitation, centrifugation and freeze-drying.

Another technical solution of the present invention is as follows:

A method for preparing a flame-retardant epoxy resin, wherein the above-mentioned POSS-DOPO-triazine derivative flame retardant self-assembles into nanoparticles in the epoxy resin during stirring and curing, specifically comprising the following steps:

(1) Weigh the glycidyl ether epoxy resin in the reaction vessel, heat it to 65-130°C, and add the POSS-DOPO-triazine derivative with self-assembly enhancing effect to flame-retardant according to the ratio of 1-30wt% agent, stir and dissolve to a uniform state, then add curing agent, stir to a uniformly dissolved state, then quickly pour it into a preheated mold, put it into an oven, set the heating program to cure, and then cool down naturally to obtain the described Flame-retardant epoxy resin; the heating program is: 115-125°C curing for 4-6 hours, 135-145°C curing for 1.8-2.2 hours, and 175-185°C curing for 1.8-2.2 hours.

In a preferred embodiment of the present invention, the epoxy resin is bisphenol A type epoxy resin.

In a preferred embodiment of the present invention, the curing agent includes aliphatic amine curing agent, aromatic amine curing agent, amidoamine curing agent, latent curing amine curing agent and urea substitute curing agent.

In a preferred embodiment of the present invention, the temperature rising program is: curing at 120° C. for 5 hours, curing at 140° C. for 2 hours, and curing at 180° C. for 2 hours.

The beneficial effects of the present invention are:

1. The present invention improves the thermal stability and flame retardancy of the epoxy resin matrix on the basis of ensuring the mechanical properties of the matrix, and has the advantages of good flame retardant effect and wide application range.

2. The POSS-DOPO-triazine derivative flame retardant of the present invention has easy-to-obtain raw materials, low cost and novel design.

3. The POSS-DOPO-triazine derivative flame retardant of the present invention simultaneously designs three flame-retardant elements, phosphorus, nitrogen, and silicon, into one molecule. Phosphorus can promote char formation, and thermal decomposition of POSS can increase the stability of the carbon layer , Nitrogen can generate gas to dilute oxygen, and the product can react organically with phosphoric acid product to increase the heat insulation of the carbon layer. The three have a synergistic flame retardant effect and can overcome the deficiency of a single flame retardant element.

4. The present invention uses cyanuric chloride as the connecting base of POSS-DOPO-triazine derivative flame retardant, which not only provides nitrogen element, but also its triazine structure can form a stable structure in the combustion process, increasing the stability of the carbon layer sex.

5. The POSS-DOPO-triazine derivative flame retardant of the present invention is applied in the modified epoxy resin, self-assembles in the matrix to form nanoparticles, and plays a role in enhancing the mechanical properties.

Description of drawings

Fig. 1 is a synthetic route diagram of the POSS-DOPO-triazine derivative flame retardant of the present invention.

Fig. 2 is the infrared spectrogram (FT-IR) of the intermediate product prepared in Example 1 of the present invention and the POSS-DOPO-triazine derivative flame retardant.

Fig. 3 is the hydrogen nuclear magnetic resonance spectrum ( ¹ H-NMR) of the intermediate product prepared in Example 1 of the present invention and the POSS-DOPO-triazine derivative flame retardant.

Fig. 4 is a scanning electron microscope (SEM) image of the self-assembly reinforced modified epoxy resin prepared in Example 1 of the present invention.

Detailed ways

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

The synthesis route of the POSS-DOPO-triazine derivative flame retardant in the following examples of the present invention is shown in FIG. 1 .

Example 1

(1) Synthesis of intermediate products

Add 1.84g (0.01mol) of cyanuric chloride and 50mL of tetrahydrofuran into a 250mL three-necked round-bottomed flask, then dissolve 4.372g (0.005mol) of POSS-NH in _50mL of tetrahydrofuran, respectively -5～0 Dissolve and stir at ℃ to obtain the first solution and the second solution, add the second solution dropwise to the first solution, stir at low temperature, slowly rise to room temperature, add the first acid-binding agent 10% _NaHCO3 solution at the same time, keep The pH value was neutral, and the reaction was carried out for 6 hours. After the reaction, the solvent was concentrated by rotary evaporation, washed with distilled water to remove the salts of the first acid-binding agent, and further precipitated with acetonitrile to obtain an intermediate product with a yield of about 83%. (2) Preparation of POSS-DOPO-triazine derivative flame retardant

The dioxane of 100mL and the dimethyl sulfoxide of 100mL were mixed to obtain the second organic solvent, and the intermediate product of 2.55g (0.0025mol) and the second organic solvent of 100mL were added to the three-neck round bottom flask of 500mL and dissolved to obtain the second organic solvent. The third solution, and then 2.82g (0.005mol) BisDOPO-OH was dissolved in 10mL of the second solvent to obtain the fourth solution, and the fourth solution was slowly added dropwise to the third solution within 1h, and the temperature was raised to 80°C, adding The second acid-binding agent triethylamine maintains the pH value of the material as neutral, and reacts for 24 hours. After the reaction, distilled water is used to remove the second acid-binding agent salts generated, and then the POSS-DOPO-triazine derivative flame retardant is obtained by precipitation with acetonitrile, and the yield is about 70% (as shown in Figure 2 and Figure 3 ).

(3) Weigh 20g of bisphenol A type epoxy resin in a single-necked flask, heat the temperature to 85°C, add 0.25g of POSS-DOPO-triazine derivative flame retardant, stir and dissolve it to a homogeneous state, Weigh 5g of curing agent 4,4-diaminodiphenylmethane and add it, stir until it is evenly dissolved, then quickly pour it into a special heated mold, put it into an oven, set the temperature rise program (cure at 120°C for 5h , 140°C for 2h, 180°C for 2h) for curing, and after a period of time, the temperature is naturally lowered to obtain a flame-retardant epoxy resin (as shown in Figure 4).

According to GB/T 2406-2009, the oxygen index of the flame-retardant epoxy resin prepared in this embodiment is 26.6%.

The flexural modulus of the flame-retardant epoxy resin of this embodiment was measured according to three-point bending, as shown in Table 1.

Example 2

(1) Synthesis of intermediate products

Add 1.84g (0.01mol) of cyanuric chloride and 50mL of tetrahydrofuran into a 250mL three-necked round-bottomed flask, then dissolve 4.372g (0.005mol) of POSS-NH in _50mL of tetrahydrofuran, respectively -5～0 Dissolve and stir at ℃ to obtain the first solution and the second solution, add the second solution dropwise to the first solution, stir at low temperature, slowly rise to room temperature, and add the first acid-binding agent 10% _NaHCO solution at the same time, Keep the pH value at neutral and react for 6h. After the reaction was completed, the solvent was concentrated by rotary evaporation, the first acid-binding agent salt was removed by washing with distilled water, and the intermediate product was obtained by further precipitation with acetonitrile, with a yield of about 83%.

(2) Preparation of POSS-DOPO-triazine derivative flame retardant

The dioxane of 100mL and the dimethyl sulfoxide of 100mL were mixed to obtain the second organic solvent, and the intermediate product of 2.55g (0.0025mol) and the second organic solvent of 100mL were added to the three-neck round bottom flask of 500mL and dissolved to obtain the second organic solvent. The third solution, and then 2.82g (0.005mol) BisDOPO-OH was dissolved in 10mL of the second organic solvent to obtain the fourth solution, and the fourth solution was slowly added dropwise to the third solution within 1h, and the temperature was raised to 80°C. Add the second acid-binding agent triethylamine to maintain the pH value of the material to be neutral, and react for 24 hours. After the reaction, distilled water is used to remove the second acid-binding agent salts generated, and then the POSS-DOPO-triazine derivative flame retardant is obtained by acetonitrile precipitation, and the yield is about 70% (using H NMR spectrum, carbon spectrum and phosphospectrometry to characterize the final product).

(3) Take 20g of bisphenol A type epoxy resin in a single-necked flask, heat the temperature up to 85°C, add 0.773g of POSS-DOPO-triazine derivative flame retardant, stir and dissolve it to a homogeneous state, Weigh 5g of 4,4-diaminodiphenylmethane and add it, stir until it is evenly dissolved, then quickly pour it into a special mold that has been heated, put it in an oven, set the temperature rise program (120°C for 5h, 140°C ℃ for 2 hours, 180 ℃ for 2 hours) to cure, and after a period of time to cool down naturally, a flame-retardant epoxy resin can be obtained.

According to GB/T 2406-2009, the oxygen index of the flame-retardant epoxy resin prepared in this embodiment is 28%.

The flexural modulus of the flame-retardant epoxy resin of this embodiment was measured according to three-point bending, as shown in Table 1.

Example 3

(1) Synthesis of intermediate products

Add 1.84g (0.01mol) of cyanuric chloride and 50mL of tetrahydrofuran into a 250mL three-necked round-bottomed flask, then dissolve 4.372g (0.005mol) of POSS-NH in _50mL of tetrahydrofuran, respectively -5～0 Dissolve and stir at ℃ to obtain the first solution and the second solution, add the second solution dropwise to the first solution, stir at low temperature, slowly rise to room temperature, and add the first acid-binding agent 10% _NaHCO solution at the same time, Keep the pH value at neutral and react for 6h. After the reaction was completed, the solvent was concentrated by rotary evaporation, the first acid-binding agent salt was removed by washing with distilled water, and the intermediate product was obtained by further precipitation with acetonitrile, with a yield of about 83%.

(2) Preparation of POSS-DOPO-triazine derivative flame retardant

The dioxane of 100mL and the dimethyl sulfoxide of 100mL were mixed to obtain the second organic solvent, and the intermediate product of 2.55g (0.0025mol) and the second organic solvent of 100mL were added to the three-neck round bottom flask of 500mL and dissolved to obtain the second organic solvent. The third solution, then dissolve 2.82g (0.005mol) BisDOPO-OH in 10mL of the second organic solvent to form the fourth solution, slowly add the fourth solution to the third solution within 1h, and the temperature rises to 80°C , add the second acid-binding agent triethylamine to maintain the pH value of the material to be neutral, and react for 24 hours. After the reaction, distilled water is used to remove the second acid-binding agent salts generated, and then the POSS-DOPO-triazine derivative flame retardant is obtained by acetonitrile precipitation, and the yield is about 70% (using H NMR spectrum, carbon spectrum and phosphospectrometry to characterize the final product).

(3) Weigh 20g of bisphenol A epoxy resin in a single-necked flask, heat the temperature to 85°C, add 0.1.316g of POSS-DOPO-triazine derivative flame retardant, stir and dissolve it to a uniform state , weigh 5g of curing agent 4,4-diaminodiphenylmethane and add it, stir until it is evenly dissolved, then quickly pour it into a special mold that has been heated, put it into an oven, set the heating program (120°C curing 5h, curing at 140°C for 2h, curing at 180°C for 2h) for curing, and after a period of time, the temperature is naturally lowered to obtain a flame-retardant epoxy resin.

According to GB/T 2406-2009, the oxygen index of the flame-retardant epoxy resin prepared in this embodiment is 30.4%.

The flexural modulus of the flame-retardant epoxy resin of this embodiment was measured according to three-point bending, as shown in Table 1.

Table 1

Flexural modulus (MPa) growth rate(%) control group 2317 0 Example 1 2446 5.56 Example 2 2541 9.67 Example 3 2695 16.3

Those of ordinary skill in the art will know that when the technical solution of the present invention changes within the following ranges, it can still obtain the same or similar technical effects as the above-described embodiments, and still belong to the protection scope of the present invention:

The preparation method of the POSS-DOPO-triazine derivative flame retardant with self-assembly enhancing effect comprises the steps:

(1) Weigh cyanuric chloride and aminopropyl oligomeric silsesquioxane (POSS-NH ₂ ), respectively dissolve in the first organic solvent, dissolve and stir at -5～0°C to obtain the first solution and The second solution, the second solution is added dropwise in the first solution, while adding the first acid-binding agent to maintain the pH value of the material, when the ratio of cyanuric chloride and aminopropyl oligomeric silsesquioxane is 1: 1～1.2, the temperature is maintained at -5～10℃; when the ratio of cyanuric chloride and aminopropyl oligomeric silsesquioxane is 1:2～2.5, the reaction temperature rises slowly to room temperature, and the reaction 2～ 8h, then remove the first organic solvent and obtain an intermediate product after purification; the first organic solvent includes dichloromethane, chloroform, ether and tetrahydrofuran, and the first acid binding agent includes aqueous sodium carbonate, aqueous sodium bicarbonate and carbonic acid Calcium aqueous solution;

(2) The above-mentioned intermediate product and BisDOPO-OH (see CN104262398A) are dissolved in the second organic solvent respectively to obtain the third solution and the fourth solution respectively, and the molar ratio of the intermediate product and BisDOPO-OH is 1: 2～2.5 or 1:1~1.2, slowly drop the fourth solution into the third solution within 1h, stir at 60~80°C, add the second acid binding agent at the same time, the reaction time is 12~24h, and then use distilled water and acetonitrile Purify to obtain the POSS-DOPO-triazine derivative flame retardant; the second organic solvent is the mixing of two kinds in dichloromethane, dioxane and dimethyl sulfoxide with a volume ratio of 1:1, so The second acid-binding agent includes triethylamine, ethylenediamine and isopropylamine;

The above-mentioned purification includes precipitation, centrifugation and lyophilization.

A method for preparing a flame-retardant epoxy resin, wherein the above-mentioned POSS-DOPO-triazine derivative flame retardant self-assembles into nanoparticles in the epoxy resin during stirring and curing, specifically comprising the following steps:

(1) Weigh the glycidyl ether epoxy resin in the reaction vessel, heat it to 65-130°C, add the POSS-DOPO-triazine derivative flame retardant according to the ratio of 1-30wt%, stir and dissolve until uniform State, then add curing agent, stir until uniformly dissolved, then quickly pour it into the preheated mold, put it into the oven, set the temperature rise program to cure, and then cool down naturally to obtain the flame retardant epoxy resin ; The heating program is: 115-125°C curing 4-6h, 135-145°C curing 1.8-2.2h, 175-185°C curing 1.8-2.2h; the curing agent includes aliphatic amine curing agent, aromatic Amine curing agents, amidoamine curing agents, latent curing amine curing agents and urea substitute curing agents.

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

Claims (9)

1. the POSS-DOPO- triazine derivative flame retardants with self assembly humidification, it is characterised in that：Its molecular structural formula It is as follows：

Wherein R is

R₁For

2. the preparation side of the POSS-DOPO- triazine derivative flame retardants with self assembly humidification described in claim 1 Method, it is characterised in that：Comprise the following steps：

(1) Cyanuric Chloride and aminopropyl oligomeric silsesquioxane (POSS-NH are weighed₂), it is dissolved in respectively in the first organic solvent ,- Stirring is dissolved at 5~0 DEG C, the first solution and the second solution is obtained, the second solution is added drop-wise in the first solution, while adds the One acid binding agent maintains the pH value of material, when the ratio of Cyanuric Chloride and aminopropyl oligomeric silsesquioxane is 1: 1~1.2, Temperature maintains -5~10 DEG C；When the ratio of Cyanuric Chloride and aminopropyl oligomeric silsesquioxane is 1: 2~2.5, reaction Temperature is slowly increased to room temperature, reacts 2~8h, then removes first organic solvent and obtains intermediate product after purifying；

(2) above-mentioned intermediate product and BisDOPO-OH are dissolved separately in the second organic solvent, respectively obtain the 3rd solution and 4th solution, intermediate product and BisDOPO-OH mol ratio are 1: 2~2.5 or 1: 1~1.2, by the 4th solution in 1h It is slowly dropped in the 3rd solution, is stirred at 60~80 DEG C, at the same the second acid binding agent of addition, 12~24h of reaction time, then Purified using distilled water and acetonitrile, it is fire-retardant to obtain the POSS-DOPO- pyrrolotriazine derivatives with self assembly humidification Agent.

3. preparation method as claimed in claim 1, it is characterised in that：The first organic solvent includes dichloro in the step (1) Methane, chloroform, ether and tetrahydrofuran, first acid binding agent include aqueous sodium carbonate, sodium bicarbonate aqueous solution and carbonic acid The calcium aqueous solution.

4. preparation method as claimed in claim 1, it is characterised in that：The second organic solvent in the step (2) is dichloro Two kinds of mixing with 1: 1 volume ratio in methane, dioxane and dimethyl sulfoxide, second acid binding agent include triethylamine, Ethylenediamine and isopropylamine.

5. preparation method as claimed in claim 1, it is characterised in that：Purification in the step (1) and (2) include precipitation, Centrifuge and lyophilized.

A kind of 6. preparation method of fire-retarded epoxy resin, it is characterised in that：In claim 1 to 5 described in any claim The POSS-DOPO- triazine derivative flame retardants with self assembly humidification in stirring and solidification process in epoxy resin In be self-assembled into nano-particle, specifically comprise the following steps：Glycidyl ether type epoxy resin is weighed in reaction vessel, is heated To 65~130 DEG C, there are the POSS-DOPO- triazine derivatives of self assembly humidification according to adding 1~30wt% ratio Thing fire retardant, stirring and dissolving to uniform state, adds curing agent, is stirred until homogeneous dissolved state, then be quickly poured into In the mould of preheating, baking oven is put into, setting heating schedule is solidified, and then Temperature fall, obtains the flame retardant epoxy tree Fat；The heating schedule is：115~125 DEG C of 4~6h of solidification, 135~145 DEG C of 1.8~2.2h of solidification, 175~185 DEG C solidify 1.8~2.2h.

7. preparation method as claimed in claim 6, it is characterised in that：The epoxy resin is bisphenol A type epoxy resin.

8. preparation method as claimed in claim 6, it is characterised in that：The curing agent includes aliphatic amine curing agent, virtue Race's amine curing agent, amide groups amine curing agent, latent solidification amine curing agent and urea substitute curing agent.

9. preparation method as claimed in claim 6, it is characterised in that：The heating schedule is：120 DEG C of solidification 5h, 140 DEG C solid Change 2h, 180 DEG C of solidification 2h.