Flame-retardant polyphenyl ether foam material and preparation method thereof

Abstract

The invention relates to the field of high polymer materials, in particular to a flame-retardant polyphenyl ether foam material and a preparation method thereof.The flame-retardant polyphenyl ether foam material is prepared from, by weight, 80-100 parts of polyphenyl ether, 8-15 parts of polyvinyl chloride resin, 1-5 parts of PPO-g-MAH, 10-20 parts of phosphoramidate flame retardant, 1-5 parts of metal oxide, 1-3 parts of plasticizer and 0.1-0.5 part of calcium-zinc stabilizer. The flame-retardant polyphenyl ether foam material prepared by the invention has excellent properties of light weight, high strength, fire prevention and flame retardance, and has wide application prospects in the fields of electronic and electrical appliances, automobile industry, mechanical industry, surgical medical instruments and the like.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, in particular to a flame retardant polyphenylene ether foaming material and a preparation method thereof. Background Art

[0002] As one of the five major engineering plastics, polyphenylene ether resin has good flame retardancy, high temperature resistance, electrical insulation, dimensional stability and excellent physical and mechanical properties. Polyphenylene ether has a wide temperature range of use, excellent dimensional stability and outstanding electrical insulation under long-term load, and is therefore widely used in the fields of electronics, automobile industry, machinery industry and surgical medical equipment. Lightweighting is an important development direction for the upgrading of polyphenylene ether materials. How to achieve high strength and light weight of polyphenylene ether materials while still maintaining their high flame retardancy has become an urgent problem to be solved. Summary of the invention

[0003] Purpose of the invention: In view of the above technical problems, the present invention proposes a flame retardant polyphenylene ether foam material and a preparation method thereof.

[0004] The technical solutions adopted are as follows: A flame retardant polyphenylene ether foam material is prepared from the following raw materials in parts by weight: 80-100 parts of polyphenylene ether, 8-15 parts of polyvinyl chloride resin, 1-5 parts of PPO-g-MAH, 10-20 parts of aminophosphoric acid ester flame retardant, 1-5 parts of metal oxide, 1-3 parts of plasticizer, and 0.1-0.5 parts of calcium zinc stabilizer.

[0005] Furthermore, the structural formula of the aminophosphoric acid ester flame retardant is as follows: ; R1-R 16 Each is independently hydrogen or an alkylamine.

[0006] Furthermore, R1-R 16 Not hydrogen at the same time.

[0007] Furthermore, one of R1 and R2 is hydrogen and the other is alkylamine, one of R3 and R4 is hydrogen and the other is alkylamine, one of R5 and R6 is hydrogen and the other is alkylamine, one of R7 and R8 is hydrogen and the other is alkylamine, and R9 and R 10 One of them is hydrogen and the other is an alkylamine, R 11 , R 12 One of them is hydrogen and the other is an alkylamine, R 13 , R 14 One of them is hydrogen and the other is an alkylamine, R 15 , R 16 One of them is hydrogen and the other is an alkylamine.

[0008] Furthermore, the alkylamine is any one or more of methylamine, ethylamine, propylamine, butylamine, pentylamine and hexylamine.

[0009] Furthermore, the alkylamine is ethylamine, that is, a monovalent group remaining after a hydrogen atom is removed from the ethyl group in the ethylamine molecule.

[0010] Furthermore, the metal oxide is rare earth-doped ZnO.

[0011] Furthermore, the preparation method of the rare earth-doped ZnO is as follows: Dissolve water-soluble zinc salt, water-soluble rare earth salt and urea in deionized water, stir and react for 1-10 hours in a water bath at 70-90°C, collect the precipitate after the reaction, wash, dry and calcine.

[0012] Furthermore, the molar ratio of the water-soluble zinc salt to the water-soluble rare earth salt is 1:0.01-0.1.

[0013] Furthermore, the water-soluble rare earth salt is a lanthanum salt.

[0014] Furthermore, the calcination temperature is 400-600° C., and the calcination time is 1-5 h.

[0015] The present invention also provides a method for preparing a flame retardant polyphenylene ether foam material: The raw materials are mixed evenly, melt blended, extruded and granulated to obtain pellets, the pellets are dried and placed in a mold for tableting, CO2 is introduced, and then the pressure is released.

[0016] Furthermore, the preparation method of the flame retardant polyphenylene ether foam material is as follows: The raw materials are mixed evenly in a high-speed mixer, melt-blended and extruded into granules through a twin-screw extruder, the obtained granules are dried and placed in a mold, and hot-pressed and cold-pressed by a flat vulcanizer to obtain a sheet. The sheet is placed in a sealed kettle filled with glycerin, and CO2 is first introduced to purge and exhaust the air. After heating, the CO2 pressure is increased to 5-10MPa and the pressure is maintained. The pressure relief valve is quickly opened and the pressure is released before taking it out.

[0017] It has the following beneficial effects: The present invention provides a flame-retardant polyphenylene ether foaming material. The polyvinyl chloride resin can improve the mechanical properties of polyphenylene ether through mechanisms such as compatibility optimization, stress dispersion toughening, processing-induced crosslinking, and functional additive synergy. This modification not only balances the rigidity and toughness of polyphenylene ether, but also improves its processing fluidity and expands its application scenarios. However, the polarity difference between the two is prone to form microphase separation. Adding PPO-g-MAH can reduce interfacial tension, thereby stabilizing melt blending and improving the mechanical properties of the material. The aminophosphoric acid ester flame retardant of the present invention is rich in amino groups in its composition structure, and can fully capture and absorb CO2 during foaming, which promotes the growth and expansion of foam cells to a certain extent, and improves the formed The morphology of the foamed pores plays a positive role in improving the mechanical properties of the material. The introduction of the triazine structure makes the aminophosphoester flame retardant have higher thermal stability and charring ability. The fire retardant performance is improved by combining the phosphorus-nitrogen synergistic effect with the dual effects of gas phase flame retardancy and condensed phase flame retardancy. ZnO as a solid acid catalyst can reduce the activation energy of the reaction of CO2 and organic amines and improve the CO2 absorption effect of amino groups. Rare earth doping further improves this catalytic effect. The flame retardant polyphenylene ether foam material prepared by the present invention has excellent properties of light weight, high strength, fire retardancy and flame retardancy, and has broad application prospects in the fields of electronic appliances, automobile industry, mechanical industry and surgical medical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the SEM image of the flame-retardant polyphenylene ether foam material prepared in Example 1. DETAILED DESCRIPTION

[0019] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially. The techniques not mentioned in the present invention are all referenced to the prior art. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0020] Polyphenylene ether: LXN-040, Nantong Xingchen Synthetic Materials Co., Ltd.; Polyvinyl chloride resin: SG-5, Wuhan Xindongyi Chemical Co., Ltd.; PPO-g-MAH: HT-029, Hengtai Plastics; Amide phosphoric acid ester flame retardant: homemade; La-doped ZnO: homemade; Plasticizer DOTP: Shandong Tenghua New Materials Co., Ltd.; Calcium zinc stabilizer: Shandong Tenghua New Materials Co., Ltd.

[0021] Embodiment 1: A flame retardant polyphenylene ether foam material is prepared from the following raw materials in parts by weight: 90 parts of polyphenylene ether, 12 parts of polyvinyl chloride resin, 2.5 parts of PPO-g-MAH, 15 parts of aminophosphoric acid ester flame retardant, 2 parts of La-doped ZnO, 3 parts of plasticizer DOTP, and 0.2 parts of calcium zinc stabilizer.

[0022] Among them, the structural formula of aminophosphoric acid ester flame retardant is as follows: ; The preparation method of aminophosphoric acid ester flame retardant is as follows: .

[0023] S1: 11 g (0.1 mol) of compound 1, 76 g (0.2 mol) of compound 2, 1.5 g of anhydrous aluminum chloride and 500 ml of toluene were added to a flask containing a stirrer, a thermometer and a reflux tube, and the temperature was raised to reflux. After stirring and reacting for 5 h, the temperature was restored to room temperature. The reaction solution was washed with 1 wt% aqueous hydrochloric acid solution, 2 wt% aqueous sodium hydroxide solution and deionized water in turn. Finally, the organic layer was separated and vacuum distilled to obtain a crude product. The crude product was purified by column chromatography (DCM: MeOH = 5: 1) to obtain compound 3 with a yield of 46.2%. ESI-MS (m / z) (M + ): Theoretical value 765.86, measured value 765.04; .

[0024] S2: 7.66 g (0.01 mol) of compound 3 and 200 ml of deionized water were added to a flask containing a stirrer, a thermometer, and a reflux tube. The temperature was raised to reflux, and 10 ml of a 50% aqueous solution of ethylenediamine was added dropwise. The reaction was continued for 2 h. During the reaction, a 2 wt % aqueous solution of sodium hydroxide was added dropwise to control the pH value of the system to 9-10. After the reaction was completed, the room temperature was restored, and the aminophosphoric acid ester flame retardant was obtained by suction filtration, washing, and drying. The yield was 75.6%, and ESI-MS (m / z) (M + ): Theoretical value 955.00, measured value 955.26.

[0025] The preparation method of La-doped ZnO is as follows: Dissolve zinc nitrate, lanthanum nitrate and urea in a molar ratio of 1:0.05:3.15 in an appropriate amount of deionized water, stir and react for 8 hours in a water bath at 80°C. After the reaction, collect the precipitate, wash it with deionized water, dry it, and calcine it in a muffle furnace at 550°C for 2 hours.

[0026] Preparation method of the flame retardant polyphenylene ether foam material: The raw materials were mixed evenly in a high-speed mixer, melt blended and extruded into granules through a twin-screw extruder. The temperatures of each section of the twin-screw extruder were: 140°C, 240°C, 280°C, 280°C, 280, 250°C, and the main engine speed was 300r / min. The obtained pellets were dried and placed in a mold, and hot-pressed at 240°C and 10MPa for 5 min on a flat vulcanizer, and then cold-pressed at room temperature and 10MPa for 3 min to obtain a sheet. The sheet was placed in a sealed kettle filled with glycerin, and CO2 was first introduced to purge 3 times to exhaust the air, the temperature was raised to 120°C, and then the CO2 pressure was raised to 8MPa and maintained for 12 hours, then the pressure relief valve was quickly opened to release the pressure to obtain the sample, and its SEM picture is shown as follows Figure 1 As shown, it can be seen that the internal bubbles are uniform and the structure is compact and dense.

[0027] Embodiment 2: A flame retardant polyphenylene ether foam material is prepared from the following raw materials in parts by weight: 100 parts of polyphenylene ether, 15 parts of polyvinyl chloride resin, 5 parts of PPO-g-MAH, 20 parts of aminophosphoric acid ester flame retardant, 5 parts of La-doped ZnO, 3 parts of plasticizer DOTP, and 0.5 parts of calcium zinc stabilizer.

[0028] The preparation methods of aminophosphoric acid ester flame retardant and La-doped ZnO are the same as those in Example 1; Preparation method of the flame retardant polyphenylene ether foam material: The raw materials were mixed evenly in a high-speed mixer, melt blended and extruded into granules through a twin-screw extruder. The temperatures of each section of the twin-screw extruder were 140°C, 240°C, 280°C, 280°C, 280, and 250°C, respectively, and the main engine speed was 300r / min. The obtained pellets were dried and placed in a mold, and hot-pressed at 240°C and 10MPa for 5 min on a flat vulcanizer, and then cold-pressed at room temperature and 10MPa for 3 min to obtain a sheet. The sheet was placed in a sealed kettle filled with glycerin, and CO2 was first introduced for 3 times to purge the air, the temperature was raised to 120°C, and then the CO2 pressure was raised to 8MPa and maintained for 12 hours, then the pressure relief valve was quickly opened to release the pressure to obtain the sample.

[0029] Embodiment 3: A flame retardant polyphenylene ether foam material is prepared from the following raw materials in parts by weight: 80 parts of polyphenylene ether, 8 parts of polyvinyl chloride resin, 1 part of PPO-g-MAH, 10 parts of aminophosphoric acid ester flame retardant, 1 part of La-doped ZnO, 1 part of plasticizer DOTP, and 0.1 part of calcium zinc stabilizer.

[0030] The preparation methods of aminophosphoric acid ester flame retardant and La-doped ZnO are the same as those in Example 1; Preparation method of the flame retardant polyphenylene ether foam material: The raw materials were mixed evenly in a high-speed mixer, melt blended and extruded into granules through a twin-screw extruder. The temperatures of each section of the twin-screw extruder were 140°C, 240°C, 280°C, 280°C, 280, and 250°C, respectively, and the main engine speed was 300r / min. The obtained pellets were dried and placed in a mold, and hot-pressed at 240°C and 10MPa for 5 min on a flat vulcanizer, and then cold-pressed at room temperature and 10MPa for 3 min to obtain a sheet. The sheet was placed in a sealed kettle filled with glycerin, and CO2 was first introduced for 3 times to purge the air, the temperature was raised to 120°C, and then the CO2 pressure was raised to 8MPa and maintained for 12 hours, then the pressure relief valve was quickly opened to release the pressure to obtain the sample.

[0031] Comparative Example 1: basically the same as Example 1, except that PPO-g-MAH was not added.

[0032] Comparative Example 2: basically the same as Example 1, except that no aminophosphoric acid ester flame retardant is added.

[0033] Comparative Example 3: It is basically the same as Example 1, except that commercially available resorcinol bis(diphenyl phosphate) is used instead of the homemade aminophosphoric acid ester flame retardant.

[0034] Comparative Example 4: is basically the same as Example 1, except that La-doped ZnO is not added.

[0035] Comparative Example 5: is basically the same as Example 1, except that commercially available ZnO is used instead of the homemade La-doped ZnO.

[0036] Performance Testing: The flame-retardant polyphenylene ether foam materials prepared in Examples 1-3 and Comparative Examples 1-5 of the present invention were made into corresponding samples for performance testing; Tensile performance test: the test standard is GB / T 1040.3-2006, the tensile rate is 5mm / min, and the sample size is 20mm×4mm×2mm; Compression performance test: the test standard is GB / T 8813-2020, the sample size is 50 mm × 50 mm × 20 mm, the compression rate is 2 mm / min, and the maximum deformation is 60%; UL94 vertical burning test: the test standard is ASTM D3801, and the sample size is 130 mm × 13 mm × 10 mm; LOI test: The test standard is GB / T 2406.2-2009, and the sample size is 100 mm×10 mm×10 mm.

[0037] The test results are shown in Table 1 below:

[0038] It can be seen from Examples 1-3 in Table 1 above that the flame-retardant polyphenylene ether foam material prepared in the present invention has excellent properties of light weight, high strength, fire resistance and flame retardancy; It can be seen from Example 1 and Comparative Example 1 that the addition of PPO-g-MAH plays a positive role in improving the mechanical strength and fire retardant properties of the flame-retardant polyphenylene ether foam material. It may be that the lack of PPO-g-MAH causes the compatibility between polyphenylene ether and polyvinyl chloride resin to deteriorate, and the phase separation causes the density to decrease. The base material content per unit volume decreases and the air increases, which makes it easier to form droplets and easier to burn, thereby resulting in a decrease in fire retardant properties. It can be seen from Example 1 and Comparative Examples 2-3 that, compared with resorcinol bis(diphenyl phosphate), the addition of the aminophosphoric acid ester flame retardant of the present invention has greatly improved the mechanical strength and fire retardant properties of the flame-retardant polyphenylene ether foam material; It can be seen from Example 1 and Comparative Examples 4-5 that, compared with ZnO, the addition of La-doped ZnO in the present invention can further improve the mechanical strength and fire retardant properties of the flame-retardant polyphenylene ether foam material.

[0039] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flame retardant polyphenylene ether foam material, characterized in that: It is prepared from the following raw materials in parts by weight: 80-100 parts of polyphenylene ether, 8-15 parts of polyvinyl chloride resin, 1-5 parts of PPO-g-MAH, 10-20 parts of aminophosphoric acid ester flame retardant, 1-5 parts of metal oxide, 1-3 parts of plasticizer, and 0.1-0.5 parts of calcium zinc stabilizer.

2. The flame-retardant polyphenylene ether foam material according to claim 1, characterized in that: The structural formula of the aminophosphoric acid ester flame retardant is as follows: ； R1-R 16 Each is independently hydrogen or an alkylamine.

3. The flame-retardant polyphenylene ether foam material according to claim 2, characterized in that: R1-R 16 Not hydrogen at the same time.

4. The flame-retardant polyphenylene ether foam material according to claim 3, characterized in that: One of R1 and R2 is hydrogen and the other is alkylamine, one of R3 and R4 is hydrogen and the other is alkylamine, one of R5 and R6 is hydrogen and the other is alkylamine, one of R7 and R8 is hydrogen and the other is alkylamine, R9 and R 10 One of them is hydrogen and the other is an alkylamine, R 11 , R 12 One of them is hydrogen and the other is an alkylamine, R 13 , R 14 One of them is hydrogen and the other is an alkylamine, R 15 , R 16 One of them is hydrogen and the other is an alkylamine.

5. The flame-retardant polyphenylene ether foam material according to claim 4, characterized in that: The alkylamine is any one or more of methylamine, ethylamine, propylamine, butylamine, pentylamine, and hexylamine.

6. The flame retardant polyphenylene ether foam material according to claim 1, characterized in that: The metal oxide is rare earth-doped ZnO.

7. The flame-retardant polyphenylene ether foam material according to claim 6, characterized in that: The preparation method of the rare earth doped ZnO is as follows: Dissolve water-soluble zinc salt, water-soluble rare earth salt and urea in deionized water, stir and react for 1-10 hours in a water bath at 70-90°C, collect the precipitate after the reaction, wash, dry and calcine.

8. The flame-retardant polyphenylene ether foam material according to claim 7, characterized in that: The molar ratio of the water-soluble zinc salt to the water-soluble rare earth salt is 1:0.01-0.

1.

9. The flame-retardant polyphenylene ether foam material according to claim 7, characterized in that: The calcination temperature is 400-600°C and the calcination time is 1-5h.

10. A method for preparing a flame-retardant polyphenylene ether foam material according to any one of claims 1 to 9, characterized in that: The raw materials are mixed evenly, melt blended, extruded and granulated to obtain pellets, the pellets are dried and placed in a mold for tableting, CO2 is introduced, and then the pressure is released.

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