阅读说明：本技术 一种阻燃涤纶丝及其制备方法 (Flame-retardant polyester yarn and preparation method thereof ) 是由 李发兴 郑荣锋 邓利进 于 2021-07-22 设计创作，主要内容包括：本申请涉及涤纶丝的领域,具体公开了一种阻燃涤纶丝及其制备方法。阻燃涤纶丝的原料包括聚酯切片、三聚氰胺氰尿酸盐复配物、磷酸三辛酯、油剂和分散剂；其制备方法为：S1：将聚酯切片、三聚氰胺氰尿酸盐复配物和分散剂混合,升温搅拌,1-1.5h后,制得混合熔体；S2：将步骤S1制得的混合熔体挤出,挤出后经过冷却、上油和卷绕,制得阻燃涤纶丝。本申请的阻燃涤纶丝可用于建筑内装饰、防护服、工业用布等领域,其具有阻燃效果好,无熔滴生成等优点。(The application relates to the field of polyester yarns, and particularly discloses a flame-retardant polyester yarn and a preparation method thereof. The raw materials of the flame-retardant polyester yarn comprise polyester chips, melamine cyanurate complex, trioctyl phosphate, oil agent and dispersant; the preparation method comprises the following steps: s1: mixing polyester chips, melamine cyanurate compound and dispersant, heating and stirring for 1-1.5h to obtain mixed melt; s2: and (5) extruding the mixed melt prepared in the step S1, and cooling, oiling and winding the extruded mixed melt to obtain the flame-retardant polyester yarn. The flame-retardant polyester yarn can be used in the fields of architectural interior decoration, protective clothing, industrial cloth and the like, and has the advantages of good flame-retardant effect, no generation of molten drops and the like.)

1. The flame-retardant polyester yarn is characterized by being prepared from the following raw materials in parts by weight:

100-120 parts of polyester chips;

10-15 parts of melamine cyanurate compound;

6-8 parts of an oil agent;

4-6 parts of a dispersing agent;

the melamine cyanurate compound is mainly prepared from 7.5-16 parts of melamine, 6.5-17 parts of cyanuric acid, 5-8 parts of trioctyl phosphate and 40-60 parts of water;

the preparation method of the melamine cyanurate compound comprises the following steps:

the method comprises the following steps: mixing melamine and cyanuric acid in water, heating to 110 ℃, and reacting for 1-1.5h to prepare a primary reaction solution;

step two: adding trioctyl phosphate into the primary reaction liquid, and mixing for 0.5-1h to prepare a melamine cyanurate compound;

wherein the weight ratio of the trioctyl phosphate to the melamine is 1 (1.5-2).

2. The flame-retardant polyester yarn as claimed in claim 1, wherein: the melamine cyanurate compound also comprises 2-10 parts of antimony hydroxide by weight.

3. The flame-retardant polyester yarn as claimed in claim 2, wherein: the antimony hydroxide is prepared by the following steps: at normal temperature, adding sodium hydroxide solution into the aqueous solution of antimony chloride, mixing and reacting for 0.5-1h, filtering and drying to obtain antimony hydroxide solid.

4. The flame-retardant polyester yarn as claimed in claim 2, wherein: the weight ratio of the antimony hydroxide to the melamine is 1 (1-3).

5. The flame-retardant polyester yarn as claimed in claim 2, wherein: the melamine cyanurate compound also comprises 1-3 parts by weight of silane coupling agent KH-560.

6. The flame-retardant polyester yarn as claimed in claim 5, wherein: in the second step, the antimony hydroxide and the silane coupling agent KH-560 are uniformly mixed to prepare a mixed solution of the antimony hydroxide and the silane coupling agent KH-560, and then the mixed solution and trioctyl phosphate are simultaneously added into the primary reaction solution and mixed for 0.5-1h to prepare the melamine cyanurate complex.

7. The flame-retardant polyester yarn as claimed in claim 1, wherein: the dispersing agent is one of sodium tripolyphosphate, sodium hexametaphosphate and sodium pyrophosphate.

8. The flame-retardant polyester yarn as claimed in claim 1, wherein: the oil agent is pentaerythritol stearate.

9. The preparation method of the flame-retardant polyester yarn as claimed in any one of claims 1 to 8, characterized by comprising the following preparation steps:

s1: mixing polyester chips, melamine cyanurate compound and dispersant, heating and stirring for 1-1.5h to obtain mixed melt;

s2: and (5) extruding the mixed melt prepared in the step S1, and cooling, oiling and winding the extruded mixed melt to obtain the flame-retardant polyester yarn.

10. The preparation method of the flame-retardant polyester yarn according to claim 9, characterized in that: in step S1, the temperature is 270-.

Technical Field

The application relates to the field of polyester yarns, in particular to a flame-retardant polyester yarn and a preparation method thereof.

Background

Polyester yarns are an important variety in synthetic fibers, and because the properties of the polyester yarns cannot meet the requirements of people for daily life, the polyester yarns are modified frequently, and the modified polyester yarns are divided into flame-retardant polyester yarns, antistatic polyester yarns, antibacterial polyester yarns and the like.

The flame retardant is added in the manufacturing process of the polyester yarn, so that the polyester yarn has a good flame retardant effect, and the flame retardant polyester fabric is applied to the fields of industrial textiles, architectural interior decoration, vehicle interior decoration, protective clothing and the like due to durable flame retardance.

The flame-retardant polyester yarn produced by the prior art is mainly prepared by mixing polyester chips and melamine cyanurate. The melamine cyanurate is rich in nitrogen elements, and can generate a large amount of nitrogen when meeting high temperature, so that the oxygen concentration on the surface of the polyester yarn and the concentration of combustible gas released by the polyester yarn are diluted, and meanwhile, the generated nitrogen can take away part of heat when overflowing, so that the temperature on the surface of the polyester yarn is reduced, and a certain flame retardant effect is generated; secondly, the product of the melamine cyanurate which is denitrified when meeting high temperature can form a carbon layer on the surface of the polyester yarn, thereby blocking oxygen to a certain extent and further generating the flame retardant effect.

In view of the above-mentioned related technologies, the inventor believes that melamine cyanurate is added to polyester filaments as a flame retardant alone, and when the polyester filaments encounter high temperature, a large amount of nitrogen generated by melamine cyanurate may affect the formation of a melamine cyanurate carbon layer to a certain extent, so that molten droplets formed by melting the interior of the flame-retardant polyester filaments may still pass through the carbon layer and drip out, and the flame-retardant effect is not ideal.

Disclosure of Invention

In order to improve the flame-retardant effect of the flame-retardant polyester yarn, the application provides the flame-retardant polyester yarn and the preparation method thereof.

In a first aspect, the present application provides a flame retardant polyester yarn, which adopts the following technical scheme:

the flame-retardant polyester yarn is prepared from the following raw materials in parts by weight:

100-120 parts of polyester chips;

10-15 parts of melamine cyanurate compound;

6-8 parts of an oil agent;

4-6 parts of a dispersing agent;

the melamine cyanurate compound is mainly prepared from 7.5-16 parts of melamine, 6.5-17 parts of cyanuric acid, 5-8 parts of trioctyl phosphate and 40-60 parts of water;

the preparation method of the melamine cyanurate compound comprises the following steps:

the method comprises the following steps: mixing melamine and cyanuric acid in water, heating to 110 ℃, and reacting for 1-1.5h to prepare a primary reaction solution;

step two: adding trioctyl phosphate into the primary reaction liquid, and mixing for 0.5-1h to prepare a melamine cyanurate compound;

wherein the weight ratio of the trioctyl phosphate to the melamine is 1 (1.5-2).

By adopting the technical scheme, trioctyl phosphate is added in the step two, the trioctyl phosphate is distributed in the molecular gap between melamine and cyanuric acid, and long-chain alkyl carried on the trioctyl phosphate separates hydrogen elements and oxygen elements in the melamine and cyanuric acid molecules, so that the possibility of forming hydrogen bonds between the hydrogen elements and the oxygen elements is reduced, interference is further realized to a certain extent, and the process of forming a hydrogen bond large-plane network structure between the melamine and cyanuric acid molecules is inhibited.

The reduction of hydrogen bonds enables the decomposition temperature of the melamine cyanurate compound to be reduced, so that the decomposition speed of the melamine cyanurate compound is accelerated when the melamine cyanurate compound meets high temperature, nitrogen can be released more quickly, the formation of a carbon layer is accelerated, and the flame retardant effect is improved.

In the melamine cyanurate compound, the damage of the large planar network structure of the hydrogen bond enables the particle size of the melamine cyanurate compound to be refined, and the volume of the particles to be reduced, thereby improving the compatibility between the melamine cyanurate compound and the polyester chips.

Trioctyl phosphate itself contains phosphorus, and thus, when exposed to high temperatures, trioctyl phosphate is thermally decomposed to form polymetaphosphoric acid. The polymetaphosphoric acid is a strong dehydrating agent, and promotes the dehydration of the terylene to form a carbon layer, so that combustible gas generated by heating the terylene is isolated from external oxygen, and the flame retardant effect is improved.

The trioctyl phosphate, the melamine and the cyanuric acid generate a synergistic effect in the process of forming the melamine cyanurate, so that the flame retardant effect of the melamine cyanurate compound can be effectively improved.

Preferably, the melamine cyanurate compound also comprises 2 to 10 parts by weight of antimony hydroxide.

By adopting the technical scheme, the antimony hydroxide is amphoteric hydroxide, and the antimony hydroxide is combined with an acid source released by the decomposition of the melamine cyanurate compound at a relatively low temperature, so that the decomposition speed of the terylene is slowed down, and the speed of generating combustible gas by the terylene is further reduced; when the temperature of the antimony hydroxide is relatively high, the acid source absorbed by the antimony hydroxide is released, the melamine cyanurate compound can be quickly dehydrated by the high-concentration acid source, the speed of forming a carbon layer by the melamine cyanurate compound is increased, and the flame retardant effect is improved.

When the temperature of the antimony hydroxide is relatively high, the antimony hydroxide is decomposed to generate water and antimony trioxide, the water and the antimony trioxide absorb a large amount of temperature to be vaporized, the temperature is reduced, and meanwhile, the oxygen concentration in the air is diluted, so that the flame retardant effect is further improved.

The antimony hydroxide and the melamine cyanurate compound generate a synergistic effect, so that the flame retardant effect of the melamine cyanurate compound is improved.

Preferably, the antimony hydroxide is prepared by the following steps: at normal temperature, adding sodium hydroxide solution into the aqueous solution of antimony chloride, mixing and reacting for 0.5-1h, filtering and drying to obtain antimony hydroxide solid.

By adopting the technical scheme, 30-40 parts of 5-6mol/L sodium hydroxide solution is added into 40-60 parts of 1-2mol/L aqueous solution of antimony chloride at the temperature of 20-25 ℃, the mixture is mixed and reacted for 0.5-1h, then the mixture is filtered at the temperature of 20-30 ℃, and the wet product is placed into a baking oven to be baked for 3-4h at the temperature of 40-60 ℃ to prepare the antimony hydroxide solid.

Preferably, the weight ratio of the antimony hydroxide to the melamine is 1 (1-3).

By adopting the technical scheme, when the weight ratio of the antimony hydroxide to the melamine is in the range of 1 (1-3), the flame retardant effect of the melamine cyanurate compound is better.

Preferably, the melamine cyanurate compound also comprises 1 to 3 parts by weight of a silane coupling agent KH-560.

By adopting the technical scheme, the silane coupling agent KH-560 improves the compatibility of the antimony hydroxide and the melamine cyanurate compound, thereby improving the flame retardant effect of the melamine cyanurate compound.

Preferably, in the second step, the antimony hydroxide and the silane coupling agent KH-560 are uniformly mixed to prepare a mixed solution of the antimony hydroxide and the silane coupling agent KH-560, and then the mixed solution and trioctyl phosphate are simultaneously added into the primary reaction solution and mixed for 0.5-1h to prepare the melamine cyanurate complex.

By adopting the technical scheme, the mixed solution is added into the primary reaction liquid after the melamine reacts with the cyanuric acid for 1-1.5h, so that the occurrence of incomplete reaction between the melamine and the cyanuric acid caused by the mixed solution is reduced. The influence of the mixed solution on the reaction between melamine and cyanuric acid is minimized.

Preferably, the dispersant is one of sodium tripolyphosphate, sodium hexametaphosphate and sodium pyrophosphate.

By adopting the technical scheme, taking sodium tripolyphosphate as an example, the sodium tripolyphosphate is complexed with nitrogen elements in the melamine cyanurate compound, so that the formation of intermolecular hydrogen bonds in the melamine cyanurate compound is further reduced, and the flame retardant effect of the melamine cyanurate compound is further improved.

Preferably, the oil agent is pentaerythritol stearate.

By adopting the technical scheme, the pentaerythritol stearate molecule has a stable symmetrical long-chain alkane structure, and the symmetrical long-chain alkane in the molecule extends into the gaps among the molecules of the polyester chip, so that the gaps among the molecules of the polyester chip are reduced, the stability of the polyester chip is improved, and the heat resistance of the polyester chip is improved.

In a second aspect, the application provides a preparation method of a flame-retardant polyester yarn, which adopts the following technical scheme:

a preparation method of flame-retardant polyester yarns comprises the following preparation steps:

s1: mixing polyester chips, melamine cyanurate compound and dispersant, heating and stirring for 1-1.5h to obtain mixed melt;

s2: and (5) extruding the mixed melt prepared in the step S1, and cooling, oiling and winding the extruded mixed melt to obtain the flame-retardant polyester yarn.

By adopting the technical scheme, the prepared flame-retardant polyester yarn has an efficient flame-retardant effect, and when meeting high temperature, the melamine cyanurate compound on the surface layer of the flame-retardant polyester yarn is quickly dehydrated to form a carbon layer coated on the surface of the polyester yarn, so that external high temperature and oxygen are isolated, meanwhile, antimony hydroxide in the melamine cyanurate compound is decomposed under a high-temperature condition to release water and antimony trioxide, and the water and the antimony trioxide are vaporized to absorb a large amount of heat, so that the temperature on the surface layer of the flame-retardant polyester yarn is quickly reduced.

Preferably, in the step S1, the temperature is 270-.

By adopting the technical scheme, the decomposition temperature of the melamine cyanurate compound is reduced compared with that of melamine cyanurate, and the melamine cyanurate compound is decomposed when the temperature is higher than 285 ℃.

In summary, the present application has the following beneficial effects:

1. the trioctyl phosphate can inhibit the formation of intermolecular hydrogen bonds between melamine and cyanuric acid in the process of forming the melamine and the cyanuric acid, so that the decomposition temperature of the melamine cyanurate compound is reduced to a certain extent, the melamine cyanurate compound can rapidly generate a large amount of nitrogen and accelerate the formation of a carbon layer of the melamine cyanurate compound when meeting high temperature, and the trioctyl phosphate has a synergistic effect in the process of forming the melamine cyanurate from the melamine and the cyanuric acid, so that the flame retardant effect of the melamine cyanurate compound can be improved.

2. Antimony hydroxide can absorb an acid source generated by the melamine cyanurate compound at a relatively low temperature, so that the decomposition of polyester is reduced, antimony hydroxide can release the acid source generated by the melamine cyanurate compound at a relatively high temperature, the speed of forming a carbon layer by the melamine cyanurate compound is accelerated, and the antimony hydroxide and the melamine cyanurate compound have a synergistic effect, so that the flame retardant effect of the melamine cyanurate compound is improved.

3. The silane coupling agent KH-560 improves the compatibility of the antimony hydroxide and the melamine cyanurate complex, so that more antimony hydroxide can be combined with the melamine cyanurate complex, and the flame retardant effect is improved.

Detailed Description

The present application will be described in further detail with reference to examples.

The polyester chip is purchased from Hongtai plastification Co., Yao, residual, the melamine cyanurate is purchased from Yin-sourced new material Co., Ltd., Guangzhou, and the melamine, the cyanuric acid, the trioctyl phosphate, the pentaerythritol stearate, the sodium tripolyphosphate, the silane coupling agent KH-560 and other raw materials are all sold in the market.

Preparation A1: the antimony hydroxide specifically adopts the components and the corresponding using amounts thereof are shown in the table 1, and is prepared by the following steps:

adding 60L of 2mol/L sodium hydroxide solution into 40L of 1mol/L antimony chloride aqueous solution at 23 ℃, stirring at the rotating speed of 173r/min, filtering after 1h, and drying at 55 ℃ for 3h to obtain an antimony hydroxide solid.

Preparation A2: antimony hydroxide, different from preparation A1 in that: the amounts and concentrations of the aqueous antimony chloride solution and the sodium hydroxide solution were varied and are shown in Table 1.

Table 1: the components and the amount thereof adopted for preparing the antimony hydroxide

Preparation B1: the melamine cyanurate compound specifically adopts the components and the corresponding amounts thereof as shown in table 2, and is prepared by the following steps:

the method comprises the following steps: mixing melamine and cyanuric acid in water, heating to 103 ℃, stirring at a rotating speed of 200r/min, and reacting for 1.3h to obtain a primary reaction solution;

step two: and adding trioctyl phosphate into the primary reaction solution, mixing and stirring for 1h, filtering, and drying at 70 ℃ for 8h to obtain the melamine cyanurate compound.

Preparation B2: melamine cyanurate formulations, distinguished from preparation B1 by: the amounts of melamine, cyanuric acid and trioctyl phosphate were varied and are shown in table 2.

Preparation B3: melamine cyanurate formulations, distinguished from preparation B1 by: antimony hydroxide from preparation A1 was added simultaneously with the trioctyl phosphate addition, as shown in Table 2.

Preparation B4: melamine cyanurate formulations, distinguished from preparation B3 by: antimony hydroxide was used in preparation A2.

Preparation examples B5-B8: melamine cyanurate formulations, distinguished from preparation B3 by: the amount of antimony hydroxide used was varied and is specifically shown in Table 2.

Preparation B9: melamine cyanurate formulations, distinguished from preparation B7 by: antimony hydroxide was added along with the silane coupling agent KH-560, as shown in Table 2.

Preparation B10: melamine cyanurate formulations, distinguished from preparation B9 by: the amount of the silane coupling agent KH-560 used was varied and is shown in Table 2.

Preparation B11: melamine cyanurate formulations, distinguished from preparation B9 by: the silane coupling agent KH-560 and the antimony hydroxide are uniformly mixed and then added with the trioctyl phosphate at the same time.

Table 2: components and amounts thereof used for the preparation of melamine cyanurate compounds

Examples

Example 1: the flame-retardant polyester yarn is prepared from the following components in parts by weight as shown in Table 3:

s1: mixing polyester chips, the melamine cyanurate compound prepared in the preparation example B1 and a dispersing agent, heating to 275 ℃, keeping the rotating speed of 213r/min, stirring for 1.5 hours, and preparing a mixed melt;

s2: and transferring the mixed melt into a screw extruder for extrusion, cooling for 1h by side blowing after extrusion, bundling after cooling, spraying an oil agent on the surface of the silk thread through an oil nozzle, standing for 1h, and winding after the silk thread absorbs the oil agent to obtain the finished flame-retardant polyester yarn.

Example 2: a flame-retardant polyester yarn is different from the polyester yarn in example 1 in that: the polyester chips, the melamine cyanurate compound and the dispersant were used in different amounts, and the melamine cyanurate compound was prepared according to preparation example B2, which is specifically shown in table 3.

Examples 3 to 11: a flame-retardant polyester yarn is different from the polyester yarn in example 1 in that: the melamine cyanurate formulation was used in the order of preparation B3-B11.

Examples 12 to 14: a flame-retardant polyester yarn, which is different from the polyester yarn prepared in example 11 in that: the components of the dispersant were varied and are specifically shown in Table 3.

Example 15: a flame-retardant polyester yarn, which is different from the polyester yarn prepared in example 12 in that: the components of the oil agent were varied and are specifically shown in Table 3.

Table 3: components and using amount of flame-retardant polyester yarn

Comparative example

Comparative example 1: the flame-retardant polyester yarn is different from the flame-retardant polyester yarn in example 1 in that: in step one, melamine cyanurate is used.

Comparative example 2: the flame-retardant polyester yarn is different from the flame-retardant polyester yarn in example 1 in that: in step S1, the melamine cyanurate compound used in the preparation of preparation B1 was added with trioctyl phosphate after the melamine reacted with cyanuric acid for 1 hour.

Comparative example 3: the flame-retardant polyester yarn is different from the comparative example 2 in that: trioctyl phosphate is added after the melamine has reacted with cyanuric acid for 2 h.

Comparative examples 4 to 5: the flame-retardant polyester yarn is different from the flame-retardant polyester yarn in example 1 in that: in step S1, the melamine cyanurate compound used in the preparation process of preparation B1 has different amounts of melamine and cyanuric acid, which is specifically shown in table 4.

Comparative example 6: the flame-retardant polyester yarn is different from the flame-retardant polyester yarn in example 1 in that: in step S1, the mixing temperature was 300 ℃.

Table 4: components and using amount of flame-retardant polyester

Performance test

Test 1: test for flame retardancy

Test subjects: the finished flame-retardant Dacron fabric having a thickness of 1mm was obtained by weaving in examples 1 to 15 and comparative examples 1 to 5, and cut into a size of 10X10 mm.

The test instrument: 250mL glass alcohol lamp, sample holder.

The test steps are as follows: using UL94V-0 vertical burning test, a bunch of cotton was placed on the bench, the sample was clamped with a sample clamp and placed vertically above the cotton, an alcohol lamp was moved to the lower end of the sample, ignited with the outer flame of the alcohol lamp, repeated 2 times, each application for 10 seconds, removed after the first ignition of the sample, and applied with a second flame after self-extinguishing. During the ignition process, the samples were observed for droplet formation and, if any, for the ability of the droplets to ignite the cotton, and the flame burn time and flameless burn time of the samples were recorded, with the results shown in table 5.

Table 5: test results of the test specimens

As can be seen from Table 5, the flame retardant polyester yarns prepared in examples 1-15 all have a flame retardant rating of UL94V-0, the flame retardant polyester yarns prepared in comparative examples 1-5 all have a flame retardant rating of UL94V-1, and the flame retardant polyester yarns prepared in comparative example 6 have a flame retardant rating of UL 94V-2.

The test results of examples 3-5 are slightly different from those of examples 6-8, because the blending ratio of antimony hydroxide and melamine in the melamine cyanurate compound of examples 6-8 is in the range of 1 (1-3), so that the synergistic effect between antimony hydroxide and melamine cyanurate compound is better, and the test results of examples 6-8 are better than those of examples 3-5.

Examples 9-10 are slightly superior to examples 6-8 because of the addition of silane coupling agent KH-560, which improves the compatibility of antimony hydroxide and melamine cyanurate complex, thereby improving flame retardant effectiveness. However, the results of example 11 are superior to those of examples 9-10 because example 11 is better than those of examples 9-10 because example 11 is mixed with the silane coupling agent KH-560 prior to adding the antimony hydroxide to the melamine cyanurate formulation, allowing the silane coupling agent KH-560 to bind more antimony hydroxide.

The results of examples 12-14 are superior to those of example 11 because the dispersant employs either sodium tripolyphosphate or hexametaphosphate or sodium pyrophosphate. The sodium polyphosphate, the sodium hexametaphosphate or the sodium pyrophosphate contains phosphorus elements in molecules, the phosphorus elements form polymetaphosphoric acid when being heated, and the polymetaphosphoric acid can accelerate the formation of a carbon layer on the surface of the terylene, so that the flame retardant effect is improved, and the results of examples 12 to 14 are better than those of example 11. Of examples 12-14, example 12 is the most effective, since the phosphorus element of the sodium tripolyphosphate complexes with the nitrogen element of the melamine cyanurate compound, thereby further inhibiting the formation of hydrogen bonds in the melamine cyanurate compound, and thus allowing the melamine cyanurate compound to release nitrogen and form a carbon layer more rapidly when heated, and thus example 12 is the most effective of examples 12-14.

The test result of the example 15 is that the test result of the example 12 is that the oil agent in the example 15 adopts pentaerythritol stearate, and when the pentaerythritol stearate is mixed with the polyester chip, the stable symmetrical long-chain alkane structure in the molecule can extend into the molecular gap of the polyester chip, so that the thermal stability of the finished polyester yarn is improved, the decomposition speed of the polyester yarn is reduced when the polyester yarn is heated, and the flame retardant effect is improved.

In comparative example 1, only melamine cyanurate was used as a flame retardant, and the flame retardant effect was single, and was not satisfactory as compared with examples 1 to 15.

In comparative example 2, trioctyl phosphate was added to the reaction solution of melamine and cyanuric acid at intervals of 1 hour, at this time, the reaction degree of melamine and cyanuric acid in the reaction solution was not sufficient, and the long-chain alkane structure in trioctyl phosphate molecule affected the reaction of melamine and cyanuric acid to some extent, resulting in insufficient reaction degree. In the reaction liquid of melamine and cyanuric acid in the comparative example 3, trioctyl phosphate is added after 2 hours, at this time, the reaction between melamine and cyanuric acid in the reaction liquid is basically finished, the intramolecular large plane hydrogen bond structure is basically formed, and at this time, the effect of adding trioctyl phosphate is greatly weakened. Therefore, the test results of comparative examples 2 to 3 were less than ideal as compared with examples 1 to 2.

In the comparative examples 4-5, the proportion range of the melamine and the trioctyl phosphate exceeds 1 (1.5-2), and the synergistic effect of the trioctyl phosphate on the melamine and the cyanuric acid in the synthesis process can be influenced by too much or too little melamine, so that the flame retardant effect is reduced.

In comparative example 6, in the process of preparing the flame retardant polyester yarn, the mixing temperature exceeded the decomposition temperature of the melamine cyanurate compound of 290 ℃, and the decomposition temperature of the melamine cyanurate compound was lower than that of the melamine cyanurate due to the reduction of the number of intermolecular hydrogen bonds. After the temperature exceeds 290 ℃, the melamine cyanurate compound is decomposed in the mixing process, so that the flame retardant effect is the worst.

Test 2: limiting oxygen index test

The test instrument: and an ASR-4328C digital display oxygen index determinator.

Test subjects: finished flame-retardant terylene cloth with the thickness of 0.5mm is obtained by weaving the terylene cloth obtained in the examples 1 to 15 and the comparative examples 1 to 5, and the finished flame-retardant terylene cloth is cut into the size of 10cm X1.5cm.

The test steps are as follows: the test sample is clamped by the test sample clamp in sequence and vertically suspended in the combustion cylinder, mixed gas flow of nitrogen and oxygen is introduced into the combustion cylinder, the oxygen concentration in the combustion cylinder is gradually increased, the oxygen concentration when the test sample is just combusted is recorded, and the percentage content of the oxygen in the combustion cylinder is the limit oxygen index at the moment.

Table 6: limiting oxygen index of the sample

The flame retardant effect of each example and the comparative example can be seen more intuitively from table 6, and in examples 1 to 15, the flame retardant effect is best that the limit oxygen index of the flame retardant polyester fabric prepared in example 15 can reach 60%. In comparative examples 1 to 6, the flame retardant effect was the worst in that the limit oxygen index of the flame-retardant polyester fabric obtained in comparative example 6 was only 30%.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.