A halogen-free flame-retardant polyester elastomer material and preparation method thereof

Abstract

The present invention discloses a halogen-free flame-retardant polyester elastomer material and a preparation method thereof. The material of the present invention is composed of the following components in mass ratio: 100 parts of polyester elastomer, 10-25 parts of main halogen-free flame retardant, 1-5 parts of auxiliary halogen-free flame retardant, 0.5-5 parts of dispersant, and 1-5 parts of molecular chain regulator; the main halogen-free flame retardant is polyester-coated micron-sized particles, and the molecular chain regulator is a composite powder of an anti-hydrolysis stabilizer, an antioxidant and a chain extender treated with ethanol. The halogen-free flame-retardant elastomer material of the present invention is prepared by extruding the uniformly mixed components through a twin-screw extruder. The halogen-free flame-retardant elastomer material prepared by the present invention has excellent flame retardant properties while maintaining good processing performance and use performance, and can be applied to cables, optical fibers, automobiles, etc. The halogen-free flame-retardant polyester elastomer material of the present invention is prepared by a twin-screw extruder, which is simple to operate, low in cost, and suitable for industrial promotion.

Description

Technical Field

[0001] The invention relates to the field of polyester elastomers, and in particular to a halogen-free flame-retardant polyester elastomer material and a preparation method thereof. Background Art

[0002] Polyester elastomer is a polymer material that has both the physical properties of rubber and the good processing properties of plastic. It has excellent high temperature resistance, impact resistance, pressure resistance, and flexural resistance while maintaining good strength. It is widely used in wires, optical cables, automobiles, etc. However, the limiting oxygen index of polyester elastomer is <20%, which is very easy to burn, which seriously hinders the development and application of polyester elastomer materials. Therefore, it is of great significance to develop polyester elastomers with excellent flame retardant properties.

[0003] Halogen-containing flame retardants are widely used because of their low price and good flame retardant effect. However, when halogen-containing flame retardants burn, they are harmful to the environment and human body. In recent years, with the strengthening of people's environmental awareness, environmentally friendly and non-toxic halogen-free flame retardants have gradually developed. However, the existing halogen-free flame retardants have limited flame retardant effects and are used in large quantities, which will also affect the processing and use performance of the materials, especially polyester elastomers. After adding flame retardant components, the performance often drops significantly. Therefore, it is necessary to develop halogen-free flame retardant elastomer materials with excellent processing and use performance. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of the present invention is to provide a method for preparing a halogen-free flame retardant polyester elastomer material. By adding a main halogen-free flame retardant and an auxiliary halogen-free flame retardant after polyester coating, the polyester elastomer can achieve an excellent and stable flame retardant effect. At the same time, the presence of a dispersant and a molecular chain regulator ensures the excellent use and processing properties of the polyester elastomer material. At the same time, the method has low cost and is suitable for industrial promotion.

[0005] Another object of the present invention is to provide a halogen-free flame-retardant polyester elastomer material having excellent flame retardant properties, mechanical properties and processing properties, and suitable for application in the fields of optical fiber cables, automobiles, etc.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for preparing a halogen-free flame-retardant polyester elastomer material, comprising the following steps:

[0008] (1) By weight:

[0009] Polyester elastomer 100 parts

[0010] Main halogen-free flame retardant 10-25 parts

[0011] Auxiliary halogen-free flame retardant 1-5 parts

[0012] Dispersant 0.5-5 parts

[0013] Molecular chain regulator 1-5 parts

[0014] The main halogen-free flame retardant is a phosphorus- and nitrogen-containing substance coated with polyester, which is a micron-sized particle; the phosphorus- and nitrogen-containing substance is obtained by mixing a phosphorus-containing compound and a nitrogen-based compound, or is a compound containing both phosphorus and nitrogen; the polyester in the main halogen-free flame retardant is the same as the polyester in the polyester elastomer;

[0015] The auxiliary halogen-free flame retardant is one of red phosphorus, carbon microspheres, and POSS;

[0016] (2) mixing a polyester elastomer, a main halogen-free flame retardant, an auxiliary halogen-free flame retardant, a dispersant, and a molecular chain regulator to obtain a halogen-free flame retardant polyester elastomer premix;

[0017] (3) Using a twin-screw extruder to extrude and granulate to obtain a halogen-free flame-retardant polyester elastomer material.

[0018] Preferably, the phosphorus-containing compound is at least one of 2-carboxyethylphenylphosphinic acid, sodium hypophosphite, calcium hypophosphite, methyl aluminum hypophosphite, diethyl aluminum hypophosphite, triethyl phosphate, and triphenyl phosphate; the nitrogen-based compound is at least one of melamine and polycyanamide; and the compound containing both phosphorus and nitrogen is at least one of melamine hypophosphite and melamine cyanurate.

[0019] Preferably, the preparation method of the main halogen-free flame retardant comprises the following steps:

[0020] (1) dissolving the polyester in an organic solvent at a temperature of 50-100° C. to prepare an organic phase solution with a mass fraction of 5-15%;

[0021] (2) adding a surfactant, sodium dodecyl sulfate, into distilled water, stirring and dissolving, and preparing an aqueous phase solution with a mass fraction of 1% to 3%;

[0022] (3) mixing the organic phase solution with the aqueous phase solution, ultrasonicating for 5-10 min, and mixing evenly to obtain a mixed solution;

[0023] (4) adding the phosphorus- and nitrogen-containing substances to the mixed solution in step (3), heating in a water bath at 30-50° C., and stirring at a stirring rate of 1000-1500 r / min for 0.5-2 h to obtain a microemulsion;

[0024] (5) adding the microemulsion to an ethanol precipitant at 0°C-4°C to prepare a polyester-coated phosphorus-containing and nitrogen-containing substance; wherein the volume ratio of the microemulsion to the ethanol precipitant is 1:3-1:6;

[0025] (6) The solid particle precipitate is filtered, washed with deionized water to remove the surfactant and solvent on the particle surface, and vacuum dried at 30° C.-60° C. to obtain micron-sized main halogen-free flame retardant particles.

[0026] Preferably, the dispersant is at least one of low molecular weight polyethylene wax, white oil, sorbitol alkylate, and poly (meth) acrylic acid derivatives.

[0027] Preferably, the molecular chain regulator is prepared from anti-hydrolysis stabilizer, antioxidant and chain extender as raw materials in a mass ratio of (1-2): (1-1.5): (0.5-0.9).

[0028] Preferably, the preparation method of the molecular chain regulator comprises the following steps:

[0029] (1) After weighing the anti-hydrolysis stabilizer, antioxidant and chain extender in proportion, add them into anhydrous ethanol, stir for 1 h to 3 h under the condition of heating in a water bath at 40° C. to fully mix them, and prepare a molecular chain regulator-ethanol solution with a mass fraction of 20% to 30%;

[0030] (2) The mixed solution is placed in an oven at 40°C-80°C for drying to obtain a powdered molecular chain regulator.

[0031] Preferably, the polyester elastomer is a block copolymer prepared by copolymerizing a polyether soft segment and a polyester hard segment.

[0032] Preferably, the polyether soft segment is at least one of polyethylene glycol, polypropylene glycol, and polybutylene glycol; the polyester hard segment is at least one of polylactic acid, polyglycolic acid, polycaprolactone, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polybutylene succinate, polyethylene furandicarboxylate, and polybutylene furandicarboxylate.

[0033] Preferably, the mixing in step (2) is specifically: mixing at a speed of 40-400 rpm for 5-10 min, and then mixing at a speed of 1500-2500 rpm; the extrusion granulation in step (3) is specifically: extrusion granulation at a screw temperature of 120-200°C and a screw speed of 150-230 rpm.

[0034] The present invention also provides a halogen-free flame-retardant polyester elastomer material, which is prepared by the preparation method of the halogen-free flame-retardant polyester elastomer material.

[0035] Preferably, the phosphorus-containing and nitrogen-containing substances are preferably melamine hypophosphite with intramolecular nitrogen-phosphorus synergistic effects. When phosphorus-containing flame retardants and nitrogen-containing flame retardants are used simultaneously, due to the synergistic and synergistic effects of nitrogen-phosphorus within or between molecules, multiple physical and chemical flame retardant mechanisms can exist simultaneously, thereby improving the flame retardant effect.

[0036] Preferably, the dispersant is a low molecular weight polyethylene wax with a molecular weight of 500-5000.

[0037] Preferably, the anti-hydrolysis stabilizer is one or a mixture of several of N,N'-bis(2,6-diisopropylphenyl)carbodiimide, mono-2-oxazoline, bis-2-oxazoline, 3-oxazoline, 4-oxazoline, phenyl glycidyl ether, triglycidyl isocyanate (TGIC), bisphenol A diglycidyl ether, tetrakis(phenylglycidyl ether)ethane, and trimethoxy[3-(glycidyl ether)propyl]silane.

[0038] Preferably, the antioxidant is one of antioxidant B215, antioxidant 1010, antioxidant 168, and antioxidant 2246, or a mixture of several of them.

[0039] Preferably, the chain extender is one or a mixture of pyromellitic anhydride, phthalic anhydride, MDI, HMDI, TTi, TDI, and phosphite.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] (1) The present invention encapsulates the halogen-free flame retardant in a polyester elastomer material and prepares it into micron-sized particles, which can effectively improve the dispersion uniformity of the flame retardant in the polyester matrix. At the same time, during the processing, the polyester molecular chains encapsulated on the outside of the halogen-free flame retardant can penetrate and entangle with the molecular chains of the polyester matrix, so that the flame retardant and the polyester matrix can achieve good compatibility.

[0042] (2) The halogen-free flame retardant polyester elastomer material of the present invention adds the polyester-coated main halogen-free flame retardant and the auxiliary halogen-free flame retardant to the polyester elastomer, so that the material has excellent flame retardant properties. The addition of dispersant and molecular chain regulator ensures the excellent processing and use performance of the material. On the whole, the material has excellent flame retardant properties and processing and use performance, and can be used in cables, optical fibers, automobiles, etc. The halogen-free flame retardant elastomer material is prepared by a twin-screw extruder, which is simple to operate, low in cost, and suitable for industrial promotion. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0044] Example 1

[0045] Preparation of polyester coated main halogen-free flame retardant:

[0046] (1) Dissolve 10 g of polyester elastomer resin in 100 ml of chloroform at 70°C to prepare an organic phase solution with a mass fraction of 10%

[0047] (2) Add 1 g of surfactant sodium dodecyl sulfate into 100 ml of distilled water and stir to dissolve to prepare an aqueous phase solution with a mass fraction of 1%;

[0048] (3) Mixing the organic phase solution with the aqueous phase solution and ultrasonicating for 10 min to make them uniformly mixed;

[0049] (4) adding 50 g of melamine hypophosphite to the mixed solution in (3), heating in a water bath at 40° C., and stirring at a stirring rate of 1500 r / min for 1 h to obtain a microemulsion;

[0050] (5) adding the microemulsion (200 ml) into 1200 ml of 0° C. ethanol precipitant (microemulsion:precipitant volume ratio 1:6) to prepare a polyester-coated main flame retardant of phosphorus-containing compound and nitrogen-based compound;

[0051] (6) The solid particle precipitate is filtered and washed with deionized water to remove the surfactant and solvent on the particle surface, and then vacuum dried at 30° C. to obtain micron-sized main halogen-free flame retardant particles for use.

[0052] Preparation of molecular chain regulator:

[0053] (1) Add 10 g of anti-hydrolysis stabilizer 3-oxazoline, 10 g of phenyl glycidyl ether, 15 g of antioxidant 1010, and 8 g of chain extender HMDI into 100 ml of anhydrous ethanol, and stir for 1 h in a 50° C. water bath to mix them thoroughly and evenly, to prepare a molecular chain regulator-ethanol solution with a mass fraction of 20%;

[0054] (2) drying the mixed solution in an oven at 80° C. to obtain a powdered molecular chain regulator for later use;

[0055] Preparation of halogen-free flame-retardant polyester elastomer materials:

[0056] 100g of polyester elastomer resin, 10g of polyester-coated main halogen-free flame retardant powder, 2g of auxiliary worry-free flame retardant red phosphorus, 1g of polyethylene wax with a dispersant number average molecular weight of 1000, and 2.5g of powdered molecular chain regulator were added to a mixer, mixed at a speed of 400rmp for 5min, and then mixed at 2000rmp for 7min to obtain a premix. The premix was extruded and granulated by a twin-screw extruder at a screw temperature of 170°C and a screw speed of 150rpm to obtain a halogen-free flame-retardant polyester elastomer material 1#.

[0057] Example 2

[0058] Preparation of polyester coated main halogen-free flame retardant:

[0059] (1) Dissolve 5 g of polyester elastomer resin in 100 ml of chloroform at 50°C to prepare an organic phase solution with a mass fraction of 5%.

[0060] (2) Add 1 g of surfactant sodium dodecyl sulfate into 100 ml of distilled water and stir to dissolve to prepare an aqueous phase solution with a mass fraction of 1%;

[0061] (3) Mixing the organic phase solution with the aqueous phase solution and sonicating for 5 minutes to make them uniformly mixed;

[0062] (4) adding 25 g of sodium hypophosphite and 25 g of melamine cyanurate to the mixed solution in (3), heating in a water bath at 50° C., and stirring at a stirring rate of 1500 r / min for 0.5 h to obtain a microemulsion;

[0063] (5) adding the microemulsion (200 ml) into 1200 ml of 0° C. ethanol precipitant (microemulsion:precipitant volume ratio 1:6) to prepare a polyester-coated main flame retardant of phosphorus-containing compound and nitrogen-based compound;

[0064] (6) The solid particle precipitate is filtered and washed with deionized water to remove the surfactant and solvent on the particle surface, and then vacuum dried at 30° C. to obtain micron-sized main halogen-free flame retardant particles for use.

[0065] Preparation of molecular chain regulator:

[0066] (1) Add 10 g of N,N'-bis(2,6-diisopropylphenyl)carbodiimide, an anti-hydrolysis stabilizer, 10 g of B215, 2 g of pyromellitic dianhydride, and 3 g of MDI to 100 ml of anhydrous ethanol, and stir for 1 h in a 40°C water bath to mix them thoroughly and evenly, to prepare a molecular chain regulator-ethanol solution with a mass fraction of 20%;

[0067] (2) drying the mixed solution in an oven at 80° C. to obtain a powdered molecular chain regulator for later use;

[0068] Preparation of halogen-free flame-retardant polyester elastomer materials:

[0069] 100g of polyester elastomer resin, 15g of polyester-coated main halogen-free flame retardant powder, 2g of auxiliary worry-free flame retardant red phosphorus, 1g of polyethylene wax with a dispersant number average molecular weight of 1000, and 3g of powdered molecular chain regulator were added to a mixer, mixed at a speed of 100rmp for 10min, and then mixed at 2500rmp for 5min to obtain a premix. The premix was extruded and granulated by a twin-screw extruder at a screw temperature of 180°C and a screw speed of 200rpm to obtain a halogen-free flame-retardant polyester elastomer material 2#.

[0070] Example 3

[0071] Preparation of polyester coated main halogen-free flame retardant:

[0072] (1) Dissolve 15 g of polyester elastomer resin in 100 ml of chloroform at 50°C to prepare an organic phase solution with a mass fraction of 15%

[0073] (2) Add 1 g of surfactant sodium dodecyl sulfate into 100 ml of distilled water and stir to dissolve to prepare an aqueous phase solution with a mass fraction of 1%;

[0074] (3) Mixing the organic phase solution with the aqueous phase solution and sonicating for 5 minutes to make them uniformly mixed;

[0075] (4) adding 25 g of methyl aluminum hypophosphite and 25 g of melamine to the mixed solution in (3), heating in a water bath at 50° C., and stirring at a stirring rate of 1500 r / min for 1.5 h to obtain a microemulsion;

[0076] (5) adding the microemulsion (200 ml) into 1200 ml of 0° C. ethanol precipitant (microemulsion:precipitant volume ratio 1:6) to prepare a polyester-coated main flame retardant of phosphorus-containing compound and nitrogen-based compound;

[0077] (6) The solid particle precipitate is filtered and washed with deionized water to remove the surfactant and solvent on the particle surface, and then vacuum dried at 30° C. to obtain micron-sized main halogen-free flame retardant particles for use.

[0078] Preparation of molecular chain regulator:

[0079] (1) Add 20 g of trimethoxy[3-(glycidylether)propyl]silane, an anti-hydrolysis stabilizer, 10 g of antioxidant 168, 3 g of chain extender TDI, and 3 g of phosphite into 100 ml of anhydrous ethanol, and stir for 1 h in a 40° C. water bath to mix them thoroughly and evenly, to prepare a molecular chain regulator-ethanol solution with a mass fraction of 20%;

[0080] (2) drying the mixed solution in an oven at 80° C. to obtain a powdered molecular chain regulator for later use;

[0081] Preparation of halogen-free flame-retardant polyester elastomer materials:

[0082] 100g of polyester elastomer resin, 25g of polyester-coated main halogen-free flame retardant powder, 2.5g of auxiliary worry-free flame retardant carbon microspheres, 1.5g of dispersant white oil, and 5g of powdered molecular chain regulator were added to a mixer, mixed at a speed of 200rmp for 7min, and then mixed at 1800rmp for 5min to obtain a premix. The premix was extruded and granulated by a twin-screw extruder at a screw temperature of 160°C and a screw speed of 250rpm to obtain a halogen-free flame retardant polyester elastomer material 3#.

[0083] Comparative Example 1

[0084] The main halogen-free flame retardant is melamine hypophosphite that is not coated with polyester, and the remaining steps are the same as those in Example 1, which is recorded as halogen-free flame retardant polyester elastomer material 4#.

[0085] Comparative Example 2

[0086] The molecular chain regulator is a direct mixture of N,N'-bis(2,6-diisopropylphenyl)carbodiimide, antioxidant B215, and chain extenders are pyromellitic dianhydride and MDI. The remaining steps are the same as those in Example 2, and are recorded as halogen-free flame-retardant polyester elastomer material 5#.

[0087] According to the national standard, the basic performance test and flame retardant performance test of the halogen-free flame retardant polyester elastomer material 1-5# were carried out. The test results are shown in Table 1.

[0088] Table 1

[0089]

[0090] It can be seen that with the increase in the amount of flame retardant added, the thermal stability of the material is slightly improved, but the elongation at break is slightly decreased (Examples 1-3); By comparing Example 1 and Comparative Example 1, it is found that the addition of the polyester-coated main halogen-free flame retardant not only improves the flame retardant properties and thermal stability of the material, but also ensures the excellent mechanical properties of the material; By comparing Example 2 and Comparative Example 2, it is found that the molecular chain regulator treated with ethanol is more conducive to ensuring the mechanical properties of the material, especially the elongation at break.

[0091] Matters not covered by the present invention are known technologies.

[0092] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a halogen-free flame-retardant polyester elastomer material, characterized in that: The method comprises the following steps: (1) weighing by weight: The main halogen-free flame retardant is a phosphorus- and nitrogen-containing substance coated with polyester, which is a micron-sized particle; the phosphorus- and nitrogen-containing substance is obtained by mixing a phosphorus-containing compound and a nitrogen-based compound, or is a compound containing both phosphorus and nitrogen; the polyester in the main halogen-free flame retardant is the same as the polyester in the polyester elastomer; The auxiliary halogen-free flame retardant is one of red phosphorus, carbon microspheres, and POSS; (2) mixing a polyester elastomer, a main halogen-free flame retardant, an auxiliary halogen-free flame retardant, a dispersant, and a molecular chain regulator to obtain a halogen-free flame retardant polyester elastomer premix; (3) Using a twin-screw extruder to extrude and granulate to obtain a halogen-free flame-retardant polyester elastomer material.

2. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 1, characterized in that: The phosphorus-containing compound is at least one of 2-carboxyethylphenylphosphinic acid, sodium hypophosphite, calcium hypophosphite, methyl aluminum hypophosphite, diethyl aluminum hypophosphite, triethyl phosphate, and triphenyl phosphate; the nitrogen-based compound is at least one of melamine and polycyanamide; and the compound containing both phosphorus and nitrogen is at least one of melamine hypophosphite and melamine cyanurate.

3. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 1 or 2, characterized in that: The preparation method of the main halogen-free flame retardant comprises the following steps: (1) dissolving the polyester in an organic solvent at a temperature of 50-100° C. to prepare an organic phase solution with a mass fraction of 5-15%; (2) adding a surfactant, sodium dodecyl sulfate, into distilled water, stirring and dissolving, and preparing an aqueous phase solution with a mass fraction of 1% to 3%; (3) mixing the organic phase solution with the aqueous phase solution, ultrasonicating for 5-10 min, and mixing evenly to obtain a mixed solution; (4) adding the phosphorus- and nitrogen-containing substances to the mixed solution in step (3), heating in a water bath at 30-50° C., and stirring at a stirring rate of 1000-1500 r / min for 0.5-2 h to obtain a microemulsion; (5) adding the microemulsion to an ethanol precipitant at 0°C-4°C to prepare a polyester-coated phosphorus-containing and nitrogen-containing substance; wherein the volume ratio of the microemulsion to the ethanol precipitant is 1:3-1:6; (6) The solid particle precipitate is filtered, washed with deionized water to remove the surfactant and solvent on the particle surface, and vacuum dried at 30° C.-60° C. to obtain micron-sized main halogen-free flame retardant particles.

4. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 1, characterized in that: The dispersant is at least one of low molecular weight polyethylene wax, white oil, sorbitol alkylate, and poly (meth) acrylic acid derivatives.

5. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 1, characterized in that: The molecular chain regulator is prepared from anti-hydrolysis stabilizer, antioxidant and chain extender in a mass ratio of (1-2): (1-1.5): (0.5-0.9) as raw materials.

6. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 5, characterized in that: The preparation method of the molecular chain regulator comprises the following steps: (1) After weighing the anti-hydrolysis stabilizer, antioxidant and chain extender in proportion, add them into anhydrous ethanol, stir for 1 h to 3 h under the condition of heating in a water bath at 40° C. to fully mix them, and prepare a molecular chain regulator-ethanol solution with a mass fraction of 20% to 30%; (2) The mixed solution is placed in an oven at 40°C-80°C for drying to obtain a powdered molecular chain regulator.

7. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 1, characterized in that: The polyester elastomer is a block copolymer prepared by copolymerizing a polyether soft segment and a polyester hard segment.

8. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 7, characterized in that: The polyether soft segment is at least one of polyethylene glycol, polypropylene glycol, and polybutylene glycol; the polyester hard segment is at least one of polylactic acid, polyglycolic acid, polycaprolactone, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polybutylene succinate, polyethylene furandicarboxylate, and polybutylene furandicarboxylate.

9. The method for preparing a halogen-free flame-retardant polyester elastomer material according to claim 1, characterized in that: The mixing in step (2) is specifically: mixing at a speed of 40-400 rpm for 5-10 min, and then mixing at a speed of 1500-2500 rpm; the extrusion granulation in step (3) is specifically: extrusion granulation at a screw temperature of 120-200° C. and a screw speed of 150-230 rpm.

10. A halogen-free flame-retardant polyester elastomer material, characterized in that: The halogen-free flame-retardant polyester elastomer material is prepared by the preparation method of any one of claims 1 to 9.

Images