阅读说明：本技术 一种低卤阻燃聚丙烯组合物及其制备方法 (Low-halogen flame-retardant polypropylene composition and preparation method thereof ) 是由 介国青 于 2020-04-01 设计创作，主要内容包括：本发明提供了一种低卤阻燃聚丙烯组合物及其制备方法,包括以下步骤：取十八水硫酸铝、尿素、山梨醇和水等反应得纳米铝晶须；在氯化镁溶液中加入PEG,混合均匀；用氨水-氯化铵缓冲液调节溶液初始pH值,水浴恒温,向氯化镁溶液中缓慢滴加沉淀剂搅拌；反应结束后将悬浮液陈化,过滤；洗涤滤饼,烘干得纳米氢氧化镁晶须；将聚丙烯粒料干燥；将聚丙烯粒料进行热炼,添加偶联剂、纳米铝晶须、纳米氢氧化镁晶须和氢氧化镁,继续热炼至混合均匀；待混合完成后,放置于模具中,于平板硫化机中热压后再冷压成型；干燥即得。本发明的低卤阻燃聚丙烯组合物卤素阻燃剂含量低,属于低卤阻燃聚丙烯材料,环保性好,同时具有卓越的阻燃性能。(The invention provides a low-halogen flame-retardant polypropylene composition and a preparation method thereof, wherein the preparation method comprises the following steps: reacting aluminum sulfate octadecahydrate, urea, sorbitol and water to obtain nano aluminum whiskers; adding PEG into the magnesium chloride solution, and uniformly mixing; adjusting the initial pH value of the solution by using an ammonia water-ammonium chloride buffer solution, keeping the temperature of the water bath constant, slowly dropwise adding a precipitator into the magnesium chloride solution, and stirring; after the reaction is finished, the suspension is aged and filtered; washing the filter cake, and drying to obtain nano magnesium hydroxide whisker; drying the polypropylene granules; carrying out cooking on the polypropylene granules, adding a coupling agent, nano aluminum whiskers, nano magnesium hydroxide whiskers and magnesium hydroxide, and continuing to carry out cooking until the materials are uniformly mixed; after mixing, placing the mixture into a mold, carrying out hot pressing in a flat vulcanizing machine, and then carrying out cold press molding; drying to obtain the product. The low-halogen flame-retardant polypropylene composition disclosed by the invention is low in halogen flame retardant content, belongs to a low-halogen flame-retardant polypropylene material, is good in environmental friendliness and has excellent flame retardant property.)

1. A preparation method of a low-halogen flame-retardant polypropylene composition is characterized by comprising the following steps: the method comprises the following steps:

(1) mixing aluminum sulfate octadecahydrate, urea, sorbitol and water uniformly;

(2) adjusting pH to 3-5 with nitric acid;

(3) putting the mixture into a high-pressure kettle, heating the mixture to 100-110 ℃, and reacting for 6-8 h;

(4) filtering the reacted solution, and drying filter residues to obtain nano aluminum whiskers;

(5) adding PEG12000 into 1.5 mol/L magnesium chloride solution, and mixing uniformly by ultrasonic oscillation;

(6) adjusting the initial pH value of the solution to 8.5 by using an ammonia water-ammonium chloride buffer solution, keeping the temperature of the solution constant in a water bath at 40 ℃, slowly dripping a precipitator into the magnesium chloride solution, and slowly stirring for 1-2 hours;

(7) after the reaction is finished, the suspension is aged for 24 hours at the temperature of 40-60 ℃ and filtered;

(8) washing the filter cake with deionized water and absolute ethyl alcohol, and drying to obtain nano magnesium hydroxide whiskers;

(9) drying the polypropylene granules in an oven at 80 ℃ for 2-3 h;

(10) carrying out heat refining on the polypropylene granules on a roller shaft of an open mill, sequentially adding a coupling agent, nano aluminum whiskers, nano magnesium hydroxide whiskers and magnesium hydroxide, and continuing heat refining until the mixture is uniformly mixed;

(11) after mixing, taking out the melt, placing the melt into a mold, placing the mold into a flat vulcanizing machine, carrying out hot pressing for 8min under the pressure of 10MPa, and then carrying out cold pressing for 5min for molding;

(12) drying and standing for 24h at room temperature to obtain the low-halogen flame-retardant polypropylene composition.

2. The method for preparing a low-halogen flame-retardant polypropylene composition according to claim 1, wherein: aluminum sulfate octadecahydrate in the step (1): urea: sorbitol: the mass ratio of water is 1: 2-3: 0.1-0.2:8-15.

3. The low-halogen flame-retardant polypropylene composition and the preparation method thereof according to claim 1, wherein the precipitant in the step (6) is 3 mol/L ammonia water or 3 mol/L NaOH solution.

4. The low-halogen flame-retardant polypropylene composition and the preparation method thereof according to claim 1, wherein the flame-retardant polypropylene composition comprises: in the step (10), the coupling agent is KH550, KH560 and KH 570.

5. The low-halogen flame-retardant polypropylene composition and the preparation method thereof according to claim 1, wherein the flame-retardant polypropylene composition comprises: the polypropylene pellets in the step (10): coupling agent: nano aluminum whisker: nano magnesium hydroxide whisker: the mass ratio of the magnesium hydroxide is 70:5:10-20:10-20: 2-5.

6. The low-halogen flame-retardant polypropylene composition and the preparation method thereof according to claim 1, wherein the flame-retardant polypropylene composition comprises: and (3) setting the temperature of a front roller of the open mill in the step (10) to be 190 ℃ and setting the temperature of a rear roller of the open mill to be 180 ℃.

7. The low-halogen flame-retardant polypropylene composition and the preparation method thereof according to claim 1, wherein the flame-retardant polypropylene composition comprises: and (3) setting the temperature of the upper layer and the lower layer of the flat vulcanizing machine to be 190 ℃ in the step (11).

8. A low-halogen flame-retardant polypropylene composition prepared by the method for preparing a low-halogen flame-retardant polypropylene composition according to claims 1 to 7.

Technical Field

The invention belongs to the field of materials, and particularly relates to a low-halogen flame-retardant polypropylene composition and a preparation method thereof.

Background

The polypropylene is a thermoplastic plastic with wide application, has the advantages of high crystallinity, regular structure, good heat resistance and the like, and is widely applied to various fields in daily life, but the limit oxygen index (L OI) of pure polypropylene resin is very low and is only 18 percent, and a large amount of molten drops are generated in the combustion process, so that the fire behavior is continuously expanded, and serious fire accidents are caused.

Disclosure of Invention

The technical problem to be solved is as follows: the invention aims to provide a low-halogen flame-retardant polypropylene composition and a preparation method thereof.

The technical scheme is as follows: a preparation method of a low-halogen flame-retardant polypropylene composition comprises the following steps:

(1) mixing aluminum sulfate octadecahydrate, urea, sorbitol and water uniformly;

(2) adjusting pH to 3-5 with nitric acid;

(3) putting the mixture into a high-pressure kettle, heating the mixture to 100-110 ℃, and reacting for 6-8 h;

(4) filtering the reacted solution, and drying filter residues to obtain nano aluminum whiskers;

(5) adding PEG12000 into 1.5 mol/L magnesium chloride solution, and mixing uniformly by ultrasonic oscillation;

(6) adjusting the initial pH value of the solution to 8.5 by using an ammonia water-ammonium chloride buffer solution, keeping the temperature of the solution constant in a water bath at 40 ℃, slowly dripping a precipitator into the magnesium chloride solution, and slowly stirring for 1-2 hours;

(7) after the reaction is finished, the suspension is aged for 24 hours at the temperature of 40-60 ℃ and filtered;

(8) washing the filter cake with deionized water and absolute ethyl alcohol, and drying to obtain nano magnesium hydroxide whiskers;

(9) drying the polypropylene granules in an oven at 80 ℃ for 2-3 h;

(10) carrying out heat refining on the polypropylene granules on a roller shaft of an open mill, sequentially adding a coupling agent, nano aluminum whiskers, nano magnesium hydroxide whiskers and magnesium hydroxide, and continuing heat refining until the mixture is uniformly mixed;

(11) after mixing, taking out the melt, placing the melt into a mold, placing the mold into a flat vulcanizing machine, carrying out hot pressing for 8min under the pressure of 10MPa, and then carrying out cold pressing for 5min for molding;

(12) drying and standing for 24h at room temperature to obtain the low-halogen flame-retardant polypropylene composition.

Further, in the step (1), the ratio of aluminum sulfate octadecahydrate: urea: sorbitol: the mass ratio of water is 1: 2-3: 0.1-0.2:8-15.

Further, in the step (6), the precipitating agent is 3 mol/L ammonia water or 3 mol/L NaOH solution.

Further, in the step (10), the polypropylene pellets: coupling agent: nano aluminum whisker: nano magnesium hydroxide whisker: the mass ratio of the magnesium hydroxide is 70:5:10-20:10-20: 2-5.

Further, in the step (10), the coupling agent is KH550, KH560 and KH 570.

Further, the temperature of the front roller of the open mill in the step (10) is set to be 190 ℃, and the temperature of the rear roller is set to be 180 ℃.

Further, the temperature of the upper layer and the lower layer of the flat vulcanizing machine in the step (11) is set to be 190 ℃.

The low-halogen flame-retardant polypropylene composition prepared by the preparation method of the low-halogen flame-retardant polypropylene composition.

The low-halogen flame-retardant polypropylene composition has the beneficial effects that the low-halogen flame-retardant polypropylene composition has low halogen flame retardant content, belongs to a low-halogen flame-retardant polypropylene material, is good in environmental protection performance, and has excellent flame retardant performance, the flame retardant grade reaches V-0 grade, the oxygen index L OI is as high as 37.8%, and generally, when the L OI reaches more than 30%, the low-halogen flame-retardant polypropylene composition belongs to a flame-retardant polymer.

Detailed Description