Boron-nitrogen flame retardant and preparation method thereof
Technical Field
The invention belongs to the technical field of organic synthesis, and particularly relates to a boron-nitrogen flame retardant and a preparation method thereof.
Background
The polymer materials are widely used in our lives, but most of the polymer materials are inflammable, and many toxic and corrosive gases and smoke can be generated during combustion, so that the consequences caused by fire disasters are very serious. Therefore, the development of flame retardants is energetically required. Currently, commonly used flame retardants include: halogen flame retardants, phosphorus flame retardants, boron flame retardants, and the like.
The halogen flame retardant can generate a large amount of smoke and toxic and harmful gases during combustion, and the use of the halogen flame retardant is gradually reduced and gradually quits the historical stage at present with increasingly strict environmental protection requirements. Phosphoric anhydride or phosphoric acid is generated in the combustion process of the phosphorus flame retardant, so that the combustible is promoted to be dehydrated and carbonized, and the generation of combustible gas is prevented or reduced, but some phosphorus flame retardants are liquid and have high volatility and poor heat resistance. The boron flame retardant mainly comprises inorganic borate such as zinc borate, borax, calcium metaborate, sodium metaborate and the like and a small amount of organic borate flame retardant.
The boron flame retardant has the advantages of good thermal stability, low toxicity, smoke abatement, easy obtainment of raw materials and the like. Reports indicate that the compounding of the boron flame retardant and the nitrogen flame retardant or the phosphorus flame retardant can play a synergistic flame retardant effect, and the combustion smoke concentration of the material can be obviously reduced after the boron flame retardant and the nitrogen flame retardant or the phosphorus flame retardant are added.
The fire retardant containing boron and nitrogen has high efficiency, low toxicity and environment friendship. When the flame retardant containing boron and nitrogen is used, at high temperature, nitrogen is heated and decomposed to release non-combustible gas, and the effects of diluting combustible gas and taking away a large amount of heat are achieved, so that the surface temperature of the polymer is reduced, and combustion is inhibited; boron produces boric anhydride or boric acid during combustion, forms a glass-like melt during thermal cracking to cover the fabric, and isolates oxygen and heat from spreading and combustible gas from diffusing outwards.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a boron-nitrogen flame retardant and a preparation method thereof.
The boron-nitrogen flame retardant comprises the following components in percentage by mass, wherein boric acid =1 (0.5-3) is used as an organic amine.
A preparation method of a boron-nitrogen flame retardant comprises the following steps:
according to the mass ratio of the boron-nitrogen flame retardant, organic amine and boric acid are uniformly mixed, and the mixture is heated to 50-90 ℃ under the stirring conditionoAnd C, stirring for 5-7 h at constant temperature, adding a solvent, and continuously and violently stirring for 5-7 h to obtain the boron-nitrogen flame retardant.
The organic amine is one of ethanolamine, diethanolamine, ethylenediamine or hydrazine hydrate.
The solvent is one or two of ethanol and water.
The boron-nitrogen flame retardant is applied to the preparation of flame-retardant textile fabrics.
The invention has the beneficial effects that:
1. the preparation method of the boron-nitrogen flame retardant provided by the invention is simple, convenient and safe to operate and low in cost.
2. The boron and nitrogen containing flame retardant provided by the invention is efficient, low in toxicity and environment-friendly.
Description of the drawings:
FIG. 1 is an IR spectrum of example 1;
FIG. 2 is an IR spectrum of example 2;
FIG. 3 is a thermogravimetric analysis spectrum of example 1;
FIG. 4 is a thermogravimetric analysis spectrum of example 2.
The specific implementation mode is as follows:
the present invention is described in detail below by way of examples, and it should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention.
Example 1:
synthesizing: adding 20 g of diethanolamine and 23.5 g of boric acid into a 250 mL round-bottom flask, heating to 70 ℃, stirring and mixing, slowly adding 10 mL of absolute ethanol under the action of continuous stirring, and continuously and violently stirring for 6 h to obtain colorless transparent colloidal viscous liquid which is the boron-nitrogen flame retardant. The infrared spectrum of the flame retardant is shown in figure 1, and the thermogravimetric analysis spectrum is shown in figure 3.
Preparing a solution: adding 1-25% of boron-nitrogen flame retardant into absolute ethyl alcohol according to the mass ratio of the flame retardant to the solvent, heating and stirring until the solution is clear, and thus obtaining the boron-nitrogen flame retardant solution.
And (3) testing: and (3) soaking a new cotton fabric or a cleaned and dried cotton fabric in the boron-nitrogen flame retardant solution, stirring for more than 15 min until the new cotton fabric or the cleaned and dried cotton fabric is completely permeated, and taking out and drying the new cotton fabric or the cleaned and dried cotton fabric.
The size of the samples in GB/T5454 is 150 mm multiplied by 58 mm, and the number of the samples is not less than 5.
Table 1 determination of oxygen index for example 1
Example 2:
synthesizing: adding 20 g of ethylenediamine and 41.2 g of boric acid into a 250 mL round-bottom flask, heating to 70 ℃, stirring and mixing, slowly adding a mixed solution of 10 mL of ethanol and 10 mL of water under the action of continuous stirring, and continuously and violently stirring for 6 h to obtain a yellowish viscous solid-liquid mixture serving as the boron-nitrogen flame retardant. The infrared spectrum of the flame retardant is shown in figure 2, and the thermogravimetric analysis spectrum is shown in figure 4.
Preparing a solution: adding 1-25% of boron-nitrogen flame retardant into a mixed solution of ethanol and water in the same volume according to the mass ratio of the flame retardant to the solvent, and heating and stirring until the solution is clear to prepare a boron-nitrogen flame retardant solution.
And (3) testing: and (3) soaking a new cotton fabric or a cleaned and dried cotton fabric in the boron-nitrogen flame retardant solution, stirring for more than 15 min until the new cotton fabric or the cleaned and dried cotton fabric is completely permeated, and taking out and drying the new cotton fabric or the cleaned and dried cotton fabric.
The size of the samples in GB/T5454 is 150 mm multiplied by 58 mm, and the number of the samples is not less than 5.
Table 2 oxygen index determination of example 2
Example 3:
adding 10 g of hydrazine hydrate (80%) and 24.7 g of boric acid into a 250 mL round-bottom flask, heating to 70 ℃, stirring and mixing, slowly adding 20 mL of ethanol solution under the action of continuous stirring, continuously and vigorously stirring for 6 h, and removing the solvent under the vacuum condition to obtain a white solid boron-nitrogen flame retardant.
Preparing a solution: adding 1-25% of flame retardant into water according to the mass ratio of the flame retardant to the solvent, heating and stirring until the solution is clear, and thus obtaining the boron-nitrogen flame retardant solution.
And (3) testing: and (3) soaking a new cotton fabric or a cleaned and dried cotton fabric in the boron-nitrogen flame retardant solution, stirring for more than 15 min until the new cotton fabric or the cleaned and dried cotton fabric is completely permeated, and taking out and drying the new cotton fabric or the cleaned and dried cotton fabric.
The size of the samples in GB/T5454 is 150 mm multiplied by 58 mm, and the number of the samples is not less than 5.
Table 3 determination of oxygen index for example 1