阅读说明：本技术 微发泡聚丙烯树脂组合物及其制备方法和用途 (Micro-foaming polypropylene resin composition and preparation method and application thereof ) 是由 刘瑞来 赵瑨云 杨为森 梁松 穆寄林 刘淑琼 吴惠民 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种微发泡聚丙烯树脂组合物,其包括按重量份数计的如下组分：聚丙烯树脂：60～100份；聚四氟乙烯树脂：10～25份；发泡材料：10～20份；可膨胀石墨：5～15份；增强材料：5～20份；增韧剂：4～10份；相容剂：2～5份；润滑剂：0.5～2份；分散剂：0.5～1.5份；抗氧化剂：0.1～0.5份。本发明克服材料因活性氢氧化铝晶须、膨胀石墨等无机粉体的加入而提高材料的摩擦系数,不利于穿线等问题,有效解决材料自重、强度及摩擦系数等问题,提高材料应用领域。(The invention discloses a micro-foaming polypropylene resin composition which comprises the following components in parts by weight: polypropylene resin: 60-100 parts; polytetrafluoroethylene resin: 10-25 parts; foaming material: 10-20 parts; expandable graphite: 5-15 parts of a solvent; reinforcing materials: 5-20 parts of a solvent; a toughening agent: 4-10 parts; a compatilizer: 2-5 parts; lubricant: 0.5-2 parts; dispersing agent: 0.5-1.5 parts; antioxidant: 0.1 to 0.5 portion. The invention overcomes the problems that the friction coefficient of the material is improved due to the addition of the inorganic powder such as the active aluminum hydroxide whisker, the expanded graphite and the like, the threading is not facilitated and the like, effectively solves the problems of the self weight, the strength, the friction coefficient and the like of the material, and improves the application field of the material.)

1. The micro-foaming polypropylene resin composition is characterized by comprising the following components in parts by weight:

2. the micro-expanded polypropylene resin composition according to claim 1, wherein the expanded material is a thermally expandable microsphere, and the method for preparing the thermally expandable microsphere comprises:

weighing 100 parts by mass of deionized water, sequentially adding 30 parts by mass of ammonium bicarbonate and 0.3 part by mass of surfactant, and fully stirring to form an ammonium bicarbonate aqueous solution, namely an aqueous solution;

weighing 100 parts by mass of dichloromethane, adding 30 parts by mass of dissolved polymethyl methacrylate, and heating to 50-70 ℃ while stirring to obtain a transparent oil-phase liquid;

adding an oil phase liquid into the water phase solution, and stirring and reacting at 50-70 ℃ for 20-24 hours under the protection of nitrogen to form a uniform emulsion;

and adjusting the pH value of the uniform emulsion to be neutral, filtering and drying to obtain the thermal expansion microspheres.

3. The micro-foamed polypropylene resin composition according to claim 2, wherein the ammonium bicarbonate has an ammonia content of 99% or more and a moisture content of 0.2% or less; the number average molecular weight of the dissolved polymethyl methacrylate is 30000-100000, and the average particle size is 5-8 mu m; the surfactant is prepared by mixing fatty alcohol-polyoxyethylene ether sodium sulfate and sodium dodecyl benzene sulfonate in a mass ratio of 1: 2.

4. The micro-expanded polypropylene resin composition according to claim 1, wherein the reinforcing material is activated aluminum hydroxide whiskers.

5. The micro-expanded polypropylene resin composition according to claim 4, wherein the active aluminum hydroxide whiskers are prepared by a method comprising:

adding 0.15mol/L aluminum sulfate solution into 0.3mol/L ammonia water, uniformly mixing, adjusting the pH value to 5.0-5.5, reacting at 220-240 ℃ for 20-24 h, cooling to room temperature, adding a coupling agent, uniformly stirring, centrifugally washing for 5 times, and drying to obtain the active aluminum hydroxide whisker; the coupling agent is a silane coupling agent.

6. The micro-expanded polypropylene resin composition according to claim 1, wherein the polytetrafluoroethylene is a suspension polytetrafluoroethylene micropowder having an average particle size of 2 to 5 μm and a molecular weight of 10000 to 30000 daltons.

7. The micro-foamed polypropylene resin composition according to claim 1, wherein the toughening agent is at least one of POE and EPDM; the compatilizer is at least one of POE-g-MAH and PP-g-MAH; the lubricant is polyethylene wax; the dispersing agent is vinyl bis stearamide; the antioxidant is a mixture of an antioxidant 1010 and a secondary antioxidant 168 with a mass ratio of 2: 1.

8. A method for preparing the micro-expanded polypropylene resin composition according to any one of claims 1 to 7, comprising the steps of:

adding expandable graphite, a reinforcing material and a dispersing agent into a high-speed mixer, heating to 90-110 ℃, stirring at the rotating speed of 150rpm for 1h, sequentially adding polypropylene resin, polytetrafluoroethylene resin, a foaming material, a toughening agent, a compatilizer, a lubricant and an antioxidant, and stirring at the rotating speed of 500rpm for 0.5h at normal temperature to obtain a premix;

adding the premix into a double-screw extruder for extrusion granulation to obtain the micro-foaming polypropylene resin composition; controlling the working parameters of the double-screw extruder as follows: the temperature of the first zone is 120-150 ℃, the temperature of the second zone is 140-180 ℃, the temperature of the third zone is 150-200 ℃, the temperature of the fourth zone is 170-210 ℃, the temperature of the fifth zone is 160-200 ℃, the temperature of the die head is 140-170 ℃, the feeding speed is 150-200 rpm, and the rotating speed of the screw is 200-400 rpm.

9. Use of the micro-foamed polypropylene resin composition according to claim 1 in a flat-walled reinforcement pipe for power cables.

10. The use according to claim 9, wherein the power cable flat-walled reinforcement pipe is prepared by a method comprising: adding the micro-foaming polypropylene resin composition into a pipe extrusion hopper of a double-screw extruder, and controlling the process parameters as follows: the temperature of the cylinder 1 zone is 160-180 ℃, the temperature of the cylinder 2 zone is 180-200 ℃, the temperature of the cylinder 3 zone is 190-220 ℃, the temperature of the cylinder 4 zone is 180-210 ℃, the temperature of the cylinder 5 zone is 160-190 ℃, the temperature of the head 1 zone is 190-210 ℃, the temperature of the cylinder 2 zone is 200-220 ℃, the temperature of the cylinder 3 zone is 160-180 ℃, and the extrusion molding speed is 0.5 m/min.

Technical Field

The invention relates to a high polymer material, in particular to a micro-foaming polypropylene resin composition, a preparation method and application thereof.

Background

Polypropylene (PP) is a semi-crystalline thermoplastic. Has high impact resistance, high mechanical property and high resistance to corrosion of various organic solvents and acid and alkali. Has wide application in industry and is one of common high molecules.

The polypropylene flat wall reinforced (IFB) pipe for power cable is a novel product in the power pipeline industry, is made of polypropylene as a main raw material by a special process, and has the advantages of high strength, good temperature resistance, high ring stiffness, and difficult fracture and aging. The method is suitable for power cables, communication optical cables, cable buried protection and the like.

At present, polypropylene flat wall reinforced (IFB) pipes for power cables are mainly solid, have large specific gravity, and particularly have the defects of dimensional deviation, high transportation cost, high installation difficulty and the like in the production, transportation and installation processes of large-diameter pipes. While the domestic patent disclosure mostly aims to improve the strength and toughness of the material, for example, the Chinese patent document CN201710543261.1 discloses a special material for a power cable sheath pipeline and a preparation method thereof, and the technical indexes of the product reach as follows: high temperature resistance (Vicat 150 ℃), low temperature resistance (drop hammer-5 ℃, no crack in 8h drop hammer), high strength (bending strength 36MPa, tensile strength 25MPa), high toughness (elongation at break 400%), and no related patent literature discloses a micro-foaming polypropylene flat wall reinforced (IFB) pipe for a power cable and a preparation method thereof.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a micro-foaming polypropylene resin composition, a preparation method and application thereof.

In order to achieve the purpose, the invention provides the following technical scheme:

a micro-foaming polypropylene resin composition comprises the following components in parts by weight:

preferably, the foaming material is a thermally expandable microsphere, and the preparation method of the thermally expandable microsphere comprises the following steps:

weighing 100 parts by mass of deionized water, sequentially adding 30 parts by mass of ammonium bicarbonate and 0.3 part by mass of surfactant, and fully stirring to form an ammonium bicarbonate aqueous solution, namely an aqueous solution;

weighing 100 parts by mass of dichloromethane, adding 30 parts by mass of dissolved polymethyl methacrylate, and heating to 50-70 ℃ while stirring to obtain a transparent oil-phase liquid;

adding an oil phase liquid into the water phase solution, and stirring and reacting at 50-70 ℃ for 20-24 hours under the protection of nitrogen to form a uniform emulsion;

and adjusting the pH value of the uniform emulsion to be neutral, filtering and drying to obtain the thermal expansion microspheres.

Preferably, the ammonia content of the ammonium bicarbonate is more than or equal to 99 percent, and the water content is less than or equal to 0.2 percent.

Preferably, the number average molecular weight of the dissolved polymethyl methacrylate is 30000 to 100000, and the average particle diameter is 5 to 8 μm.

Preferably, the surfactant is prepared by mixing fatty alcohol-polyoxyethylene ether sodium sulfate and sodium dodecyl benzene sulfonate in a mass ratio of 1: 2.

Preferably, the reinforcing material is activated aluminum hydroxide whisker.

Preferably, the preparation method of the active aluminum hydroxide whisker comprises the following steps:

adding 0.15mol/L aluminum sulfate solution into 0.3mol/L ammonia water, uniformly mixing, adjusting the pH value to 5.0-5.5, reacting at 220-240 ℃ for 20-24 h, cooling to room temperature, adding a coupling agent, uniformly stirring, centrifugally washing for 5 times, and drying to obtain the active aluminum hydroxide whisker.

Preferably, the coupling agent is a silane coupling agent.

As a preferable scheme, the polytetrafluoroethylene is suspension polytetrafluoroethylene ultrafine powder, the average particle size is 2-5 mu m, and the molecular weight is 10000-30000 daltons.

Preferably, the toughening agent is at least one of POE and EPDM; the compatilizer is at least one of POE-g-MAH and PP-g-MAH; the lubricant is polyethylene wax; the dispersing agent is vinyl bis stearamide; the antioxidant is a mixture of an antioxidant 1010 and a secondary antioxidant 168 with a mass ratio of 2: 1.

A method for preparing the micro-foaming polypropylene resin composition comprises the following steps:

adding expandable graphite, a reinforcing material and a dispersing agent into a high-speed mixer, heating to 90-110 ℃, stirring at the rotating speed of 150rpm for 1h, sequentially adding polypropylene resin, polytetrafluoroethylene resin, a foaming material, a toughening agent, a compatilizer, a lubricant and an antioxidant, and stirring at the rotating speed of 500rpm for 0.5h at normal temperature to obtain a premix;

adding the premix into a double-screw extruder for extrusion granulation to obtain the micro-foaming polypropylene resin composition; controlling the working parameters of the double-screw extruder as follows: the temperature of the first zone is 120-150 ℃, the temperature of the second zone is 140-180 ℃, the temperature of the third zone is 150-200 ℃, the temperature of the fourth zone is 170-210 ℃, the temperature of the fifth zone is 160-200 ℃, the temperature of the die head is 140-170 ℃, the feeding speed is 150-200 rpm, and the rotating speed of the screw is 200-400 rpm.

Use of a micro-foamed polypropylene resin composition as described above in a flat-walled reinforcement pipe for a power cable.

Preferably, the preparation method of the power cable flat-wall reinforced pipe comprises the following steps:

adding the micro-foaming polypropylene resin composition into a pipe extrusion hopper of a double-screw extruder, and controlling the process parameters as follows: the temperature of the cylinder 1 zone is 160-180 ℃, the temperature of the cylinder 2 zone is 180-200 ℃, the temperature of the cylinder 3 zone is 190-220 ℃, the temperature of the cylinder 4 zone is 180-210 ℃, the temperature of the cylinder 5 zone is 160-190 ℃, the temperature of the head 1 zone is 190-210 ℃, the temperature of the cylinder 2 zone is 200-220 ℃, the temperature of the cylinder 3 zone is 160-180 ℃, and the extrusion molding speed is 0.5 m/min.

The invention has the beneficial effects that as the key point of the invention, in the process of preparing the polypropylene flat wall reinforced (IFB) pipe for the power cable, the self-made thermal expansion microsphere foaming material and the active aluminum hydroxide whisker reinforced material are added to cooperate with the expanded graphite to prepare the micro-foaming polypropylene flat wall reinforced (IFB) pipe for the power cable. Under normal conditions, if the microcellular foamed material is prepared by simply adding the thermally expandable microspheres, the tensile strength and the ring stiffness of the material are obviously affected, and the effect cannot be exerted to the best. According to the scheme for solving the problem, the thermal expansion microspheres are added to reduce the self weight of the material, and simultaneously, the reinforcing materials such as the active aluminum hydroxide whiskers and the thermal expansion graphite are added to improve the strength of the material while reducing the self weight of the material, and meanwhile, the polytetrafluoroethylene resin is innovatively added to overcome the problems that the friction coefficient of the material is improved due to the addition of the inorganic powder such as the active aluminum hydroxide whiskers and the expansion graphite, the threading is not facilitated, the problems of the self weight, the strength, the friction coefficient and the like of the material are effectively solved, and the application field of the material is improved.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.