Preparation process of organic fireproof flame retardant

Abstract

The invention relates to the field of fire prevention of high polymer materials, and discloses a preparation process of an organic fireproof flame retardant, the organic fireproof flame retardant participates in the preparation process of the flame retardant by preparing vinyl sodium alginate and maleic anhydride castor oil, sodium alginate in the vinyl sodium alginate structure can dilute combustible gas, and the flame retardant has good flame retardant property. A carbon layer is strengthened, phosphate ester can be decomposed into phosphoric acid substances at high temperature, and the material is effectively catalyzed to be dehydrated into carbon to play a flame-retardant effect; a castor oil long chain in a maleic anhydride castor oil structure and a maleic anhydride group can enhance the compatibility between the flame retardant and a used material, when a fire disaster occurs, the introduction of allyl methyl sulfide can provide a sulfur element, and all the components are subjected to a free radical polymerization reaction through alkenyl to form a cross-linked network structure, so that the compactness is enhanced, and the flame retardance is improved. Therefore, small molecular effective substances are not easy to migrate, the effective time of the flame retardant is remarkably prolonged, and a more excellent flame-retardant effect is achieved.

Description

Technical Field

[0001] The present invention relates to the field of fire prevention of polymer materials, and particularly to a preparation process of an organic fire retardant. Background Art

[0002] With the wide application of polymer materials in daily life, industrial production, construction and other fields, the fire hazards caused by their flammability have become increasingly prominent. As an additive to improve the fire prevention ability of polymer materials, the performance of fire retardants is directly related to the safety and reliability of materials. At present, fire retardants are mainly divided into two categories, inorganic fire retardants and organic fire retardants. Although inorganic fire retardants have good fire retardant effects, their compatibility with polymer materials is very poor, which easily leads to the loss of mechanical properties of polymer materials. Although organic fire retardants have better compatibility with materials, most fire retardants are small molecules. Small molecule fire retardants are prone to migration during long-term use, resulting in the loss of fire retardant function of materials. Moreover, the current organic fire retardants generally have general fire retardant effects and are difficult to meet the usage requirements in various situations.

[0003] The patent with the publication number CN108342133B discloses a method for preparing perchloroethylene fireproof coatings using loaded amine perlite as a fire retardant. A high-quality fire retardant, melamine cyanurate, is selected and placed in a mixed solvent, and then perlite ore powder and bentonite are added. After heating and stirring, an ionization reaction occurs to obtain a composite fire retardant. Compared with the simply mixed fire retardants, the structure and properties of this composite fire retardant have changed greatly and have excellent fire prevention effects. However, the compounded fire retardant in this patent uses a variety of inorganic substances and has general compatibility with materials, posing potential safety hazards. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation process of an organic fire retardant, which solves the problems that ordinary organic fire retardants are prone to precipitation of small molecule active substances and the fire retardant performance needs to be improved.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A preparation process of an organic fire retardant includes the following preparation steps: Step 1: Mix sodium alginate vinyl, maleic anhydride castor oil, and allyl methyl sulfide in dimethyl sulfoxide and stir for 1 - 2 h to obtain a mixed solution; Step 2: Add an initiator to the mixed solution and mix evenly, heat up to 65 - 75 °C and react for 6 - 8 h, and remove low-boiling substances by vacuum distillation to collect the product to obtain the organic fire retardant.

[0006] Furthermore, the mass ratio of the sodium alginate vinyl, maleic anhydride modified castor oil, allyl methyl sulfide, dimethyl sulfoxide, and initiator is 10 - 15:15 - 20:5 - 8:100 - 120:3 - 5.

[0007] Furthermore, the initiator is any one of benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, and azobisisoheptonitrile.

[0008] Furthermore, the preparation method of the sodium alginate vinyl includes the following steps: Mix sodium alginate, vinylphosphonic acid, and a water-carrying agent evenly, heat up to reflux for reaction, cool to room temperature, and collect the product to obtain sodium alginate vinyl.

[0009] In this solution, under the action of the water-carrying agent, the hydroxyl group in the sodium alginate structure reacts with the phosphate group in the vinylphosphonic acid structure to obtain sodium alginate vinyl. This sodium alginate vinyl structure contains active alkenyl groups, which can participate in the preparation process of the flame retardant. At the same time, sodium alginate has a bio-based swelling property, can release crystal water and expand at high temperatures, dilute combustible gases, and can strengthen the heat insulation effect of the carbon layer during a fire. Vinylphosphonic acid is connected to the backbone of the polymer sodium alginate by chemical bonding, which can effectively avoid the migration phenomenon of small molecule phosphonic acid compounds during long-term use. And the formed phosphate ester can decompose to produce phosphoric acid substances at high temperatures, which can effectively catalyze the dehydration and carbonization of materials such as sodium alginate to form a dense carbon layer, isolate oxygen and heat transfer, and effectively improve the flame retardant effect of the flame retardant. The introduction of vinyl can endow sodium alginate with the ability of free radical polymerization. Under the action of the initiator, it can copolymerize with the monomers in the flame retardant matrix material to produce a cross-linked network structure, which can effectively enhance the stability of the carbon layer during combustion, inhibit dripping, so that the prepared flame retardant can effectively enhance the flame retardant performance, and the flame retardant ability is not easily lost, having a long service life.

[0010] Furthermore, the water-carrying agent is cyclohexane.

[0011] Furthermore, the time for the reflux reaction under heating is 10 - 15 h.

[0012] Furthermore, the preparation method of the maleic anhydride modified castor oil includes the following steps: S1: Place castor oil and glycine in toluene, fully mix and stir, then add p-toluenesulfonic acid, heat up for reaction, and collect the product by vacuum distillation to obtain modified castor oil; S2: Place the modified castor oil and bromomaleic anhydride in acetone, add a catalyst, heat up to 45 - 50 °C and stir for 2 - 3 h, and collect the product by vacuum distillation to obtain maleic anhydride modified castor oil.

[0013] In this solution, under the action of p-toluenesulfonic acid, the hydroxyl group in the castor oil structure reacts with the carboxyl group in the glycine structure to obtain modified castor oil. Then, under the action of a catalyst, the amino group in the modified castor oil structure reacts with the active bromine in the structure of bromomaleic anhydride to obtain maleic anhydride-modified castor oil. The bromine element in this maleic anhydride-modified castor oil can interrupt the combustion reaction through the gas-phase free radical capture mechanism. The long-chain fatty acid ester in the castor oil structure can entangle with the polyolefin matrix material, effectively enhancing the compatibility between the flame retardant and the matrix material. And it can produce a synergistic effect with the phosphate group in the structure of vinyl sodium alginate to promote carbon formation, forming a dual flame retardant path. At the same time, as a renewable raw material, castor oil can endow the flame retardant with partial biodegradability, effectively reducing the environmental burden. And the maleic anhydride group in its structure can increase the crosslinking density of the flame retardant, improve its thermal stability, and at the same time enhance the compatibility between the flame retardant and materials in use such as polyolefins, so that small molecule flame retardant substances will not easily precipitate even during long-term use, making it play a more long-lasting and stable flame retardant effect.

[0014] Further, in step S1, the temperature of the temperature-rising reaction is 85 - 95 °C, and the time is 3 - 5 h.

[0015] Further, in step S2, the catalyst is any one of pyridine and potassium carbonate.

[0016] Advantages of the present invention: In the present invention, vinyl sodium alginate and maleic anhydride-modified castor oil are prepared and involved in the preparation process of the flame retardant. The sodium alginate in the structure of vinyl sodium alginate can dilute combustible gases and strengthen the carbon layer. Phosphate esters can decompose into phosphoric acid substances at high temperatures, effectively catalyzing the dehydration of materials to form a carbon layer and exerting a flame retardant effect. The castor oil long chain and maleic anhydride group in the structure of maleic anhydride-modified castor oil can enhance the compatibility between the flame retardant and materials in use. At the same time, when a fire occurs, the introduction of allyl methyl sulfide can provide sulfur elements, greatly improving the flame retardant effect of the flame retardant through the cooperation of each component. And each component undergoes a free radical polymerization reaction through alkenyl groups to form a crosslinked network structure, enhancing the compactness, making it difficult for small molecule effective substances to migrate, significantly prolonging the effective time of the flame retardant, and promoting the formation of a denser carbon layer at high temperatures to inhibit the combustion rate, further exerting a more excellent flame retardant effect.

[0017] Of course, it is not necessary for any product implementing the present invention to simultaneously achieve all the above-mentioned advantages. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is the flow chart for the preparation of the organic fire retardant of the present invention. Specific embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0021] The preparation methods of sodium alginate vinyl and maleic anhydride castor oil in the following embodiments and comparative examples of the present invention are as follows: I. Sodium alginate vinyl Mix 3 g of sodium alginate, 2.6 g of vinylphosphonic acid and 2 g of cyclohexane evenly, heat up to 70 °C and reflux for 10 h, collect the product after cooling to room temperature to obtain sodium alginate vinyl.

[0022] II. Preparation of maleic anhydride castor oil S1: Place 3.2 g of castor oil and 2.8 g of glycine in 60 ml of toluene, fully mix and stir, then add 0.08 g of p-toluenesulfonic acid, heat up to 85 °C and react for 3 h, collect the product after vacuum distillation to obtain modified castor oil; S2: Place 4.6 g of modified castor oil and 3.8 g of bromomaleic anhydride in 80 ml of acetone, add 0.03 g of pyridine, heat up to 45 °C and stir for 2 h, collect the product after vacuum distillation to obtain maleic anhydride castor oil. Example 1

[0023] Preparation of organic fire retardant Step 1: Mix 10 parts of sodium alginate vinyl, 15 parts of maleic anhydride castor oil and 5 parts of allylmethyl sulfide in 100 parts of dimethyl sulfoxide and stir for 1 h to obtain a mixed solution; Step 2: Add 3 parts of benzoyl peroxide to the mixed solution and mix evenly, heat up to 65 °C and react for 6 h, remove the low-boiling substances by vacuum distillation, and collect the product to obtain the organic fire retardant. Example 2

[0024] Preparation of organic fire retardant Step 1: Place 11 parts of sodium alginate vinyl, 16 parts of maleated castor oil, and 6 parts of allyl methyl sulfide in 105 parts of dimethyl sulfoxide and mix and stir for 1.2 h to obtain a mixed solution; Step 2: Add 3.5 parts of benzoyl peroxide to the mixed solution and mix evenly. Heat up to 68 °C and react for 6.5 h. Distill off the low-boiling substances under reduced pressure and collect the product to obtain an organic fire retardant. Example 3

[0025] Preparation of organic fire retardant Step 1: Place 12 parts of sodium alginate vinyl, 17 parts of maleated castor oil, and 6.5 parts of allyl methyl sulfide in 110 parts of dimethyl sulfoxide and mix and stir for 1.5 h to obtain a mixed solution; Step 2: Add 4 parts of benzoyl peroxide to the mixed solution and mix evenly. Heat up to 70 °C and react for 7 h. Distill off the low-boiling substances under reduced pressure and collect the product to obtain an organic fire retardant. Example 4

[0026] Step 1: Place 13 parts of sodium alginate vinyl, 18 parts of maleated castor oil, and 7 parts of allyl methyl sulfide in 115 parts of dimethyl sulfoxide and mix and stir for 1.8 h to obtain a mixed solution; Step 2: Add 4.5 parts of benzoyl peroxide to the mixed solution and mix evenly. Heat up to 72 °C and react for 7.5 h. Distill off the low-boiling substances under reduced pressure and collect the product to obtain an organic fire retardant. Example 5

[0027] Step 1: Place 15 parts of sodium alginate vinyl, 20 parts of maleated castor oil, and 8 parts of allyl methyl sulfide in 120 parts of dimethyl sulfoxide and mix and stir for 2 h to obtain a mixed solution; Step 2: Add 5 parts of benzoyl peroxide to the mixed solution and mix evenly. Heat up to 75 °C and react for 8 h. Distill off the low-boiling substances under reduced pressure and collect the product to obtain an organic fire retardant.

[0028] Comparative Example 1 Preparation of organic fire retardant Step 1: Place 16 parts of maleated castor oil and 6 parts of allyl methyl sulfide in 105 parts of dimethyl sulfoxide and mix and stir for 1.2 h to obtain a mixed solution; Step 2: Add 3.5 parts of benzoyl peroxide to the mixed solution and mix evenly. Heat up to 68 °C and react for 6.5 h. Distill off the low-boiling substances under reduced pressure and collect the product to obtain an organic fire retardant.

[0029] Comparative Example 2 Preparation of organic fire retardant Step 1: Mix 11 parts of sodium alginate vinyl and 6 parts of allyl methyl sulfide in 105 parts of dimethyl sulfoxide and stir for 1.2 h to obtain a mixed solution; Step 2: Add 3.5 parts of benzoyl peroxide to the mixed solution, mix evenly, heat up to 68 °C and react for 6.5 h, distill off the low-boiling substances under reduced pressure, and collect the product to obtain an organic fire retardant.

[0030] Comparative Example 3 Preparation of Organic Fire Retardant Step 1: Mix 11 parts of sodium alginate vinyl and 16 parts of maleic anhydride castor oil in 105 parts of dimethyl sulfoxide and stir for 1.2 h to obtain a mixed solution; Step 2: Add 3.5 parts of benzoyl peroxide to the mixed solution, mix evenly, heat up to 68 °C and react for 6.5 h, distill off the low-boiling substances under reduced pressure, and collect the product to obtain an organic fire retardant.

[0031] Performance Testing Add 2 g of the organic fire retardants prepared in Examples 1 - 5 and Comparative Examples 1 - 3 respectively, and 100 g of polypropylene material into a twin-screw extruder. Set the screw speed to 150 r / min and the temperature of the extruder head to 180 °C, melt extrude and pelletize to obtain polypropylene composites. Take them as samples and use the UL-94 flame retardant rating standard to test the flame retardant performance of the samples. The specific test results are shown in the following table:

[0032] As can be seen from the above table, the samples prepared in Examples 1 - 5 all have good flame retardant performance. This is because sodium alginate vinyl, maleic anhydride castor oil, and allyl methyl sulfide are added to them. Through the polymerization of the three, the compatibility between the flame retardant and polyolefin is significantly improved. At the same time, through the flame retardant action of elements such as nitrogen, phosphorus, sulfur, and chlorine and the promotion between sodium alginate and castor oil, an excellent flame retardant system is formed, enabling the samples to exhibit excellent flame retardant ability. In the sample prepared in Comparative Example 1, sodium alginate vinyl is not added, resulting in low char formation efficiency and poor flame retardant ability without the addition of phosphate groups. In the sample prepared in Comparative Example 2, maleic anhydride castor oil is not added, resulting in poor compatibility with polyolefin, so the flame retardant effect is average. In the sample prepared in Comparative Example 3, allyl methyl sulfide is not added, resulting in a reduction in flame retardant ability due to the lack of participation of sulfur element, which is inferior to that of the examples.

[0033] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0034] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A preparation process of an organic fire retardant, characterized in that, It includes the following preparation steps: Step 1: Mix sodium alginate vinyl, maleic anhydride castor oil, and allyl methyl sulfide in dimethyl sulfoxide and stir for 1 - 2 h to obtain a mixed solution; Step 2: Add an initiator to the mixed solution and mix evenly. Heat up to 65 - 75 °C and react for 6 - 8 h. Remove low-boiling substances by vacuum distillation and collect the product to obtain an organic fire retardant.

2. The preparation process of an organic fire retardant according to claim 1, characterized in that, The mass ratio of sodium alginate vinyl, maleic anhydride castor oil, allyl methyl sulfide, dimethyl sulfoxide, and initiator is 10 - 15:15 - 20:5 - 8:100 - 120:3 - 5.

3. The preparation process of an organic fire retardant according to claim 1, characterized in that, The initiator is any one of benzoyl peroxide, diisopropylbenzene peroxide, azobisisobutyronitrile, and azodiisooctanenitrile.

4. The preparation process of an organic fire retardant according to claim 1, characterized in that, The preparation method of the sodium alginate vinyl includes the following steps: Mix sodium alginate, vinyl phosphonic acid, and a water-carrying agent evenly, heat up to reflux and react. After cooling to room temperature, collect the product to obtain sodium alginate vinyl.

5. The preparation process of an organic fire retardant according to claim 4, characterized in that, The water-carrying agent is cyclohexane.

6. The preparation process of an organic fire retardant according to claim 4, characterized in that, The time for the heating reflux reaction is 10 - 15 h.

7. The preparation process of an organic fire retardant according to claim 1, characterized in that, The preparation method of the maleic anhydride castor oil includes the following steps: S1: Place castor oil and glycine in toluene, fully mix and stir, then add p-toluenesulfonic acid, heat up and react. After vacuum distillation, collect the product to obtain modified castor oil; S2: Place the modified castor oil and bromo maleic anhydride in acetone, add a catalyst, heat up to 45 - 50 °C and stir for 2 - 3 h. After vacuum distillation, collect the product to obtain maleic anhydride castor oil.

8. The preparation process of an organic fire retardant according to claim 7, characterized in that, In step S1, the temperature for the heating reaction is 85 - 95 °C and the time is 3 - 5 h.

9. The preparation process of an organic fire retardant according to claim 7, characterized in that, In step S2, the catalyst is any one of pyridine and potassium carbonate.

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