CN112480552A - Polypropylene composite material and preparation method thereof - Google Patents
Polypropylene composite material and preparation method thereof Download PDFInfo
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- CN112480552A CN112480552A CN202011392689.9A CN202011392689A CN112480552A CN 112480552 A CN112480552 A CN 112480552A CN 202011392689 A CN202011392689 A CN 202011392689A CN 112480552 A CN112480552 A CN 112480552A
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/10—Homopolymers or copolymers of propene
- C08L23/14—Copolymers of propene
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/016—Additives defined by their aspect ratio
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
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Abstract
The invention discloses a polypropylene composite material, and relates to the technical field of composite materials. The polypropylene composite material comprises the following components in percentage by mass: 50-75% of polypropylene, 5-20% of low-density polyethylene, 5-15% of a toughening agent, 4-12% of a filler, 3-8% of glass fiber powder, 0.3-1% of a stabilizer and 0.2-2% of a lubricant. According to the invention, polypropylene is used as a base material, and low-density polyethylene, glass fiber powder and a filler are added, so that the prepared polypropylene composite material has the characteristics of low density and low shrinkage, and meets the requirement of light weight.
Description
Technical Field
The invention relates to the technical field of composite materials, in particular to a polypropylene composite material and a preparation method thereof.
Background
With the development of the automobile industry and the improvement of the living standard of people, the requirements of energy conservation and environmental protection are higher and higher. The design and application of the concept of light weight of automobiles have become a trend and trend. On the premise of ensuring the safety and the comfort of the automobile, the weight of the automobile is reduced as much as possible by means of a lightweight technology, so that the purposes of high output rate, low noise, low vibration, good maneuverability, high reliability and the like are achieved.
The current automobile light-weight method comprises light-weight materials, a light-weight process and a light-weight design. Polypropylene is an important lightweight material applied to automobiles as a thermoplastic resin which has light weight, low price, chemical resistance, easy processing and forming and excellent comprehensive performance. Meanwhile, low-density polypropylene, thin-walled injection-molded PP and micro-foamed PP are main methods for lightening modified materials. The thin-walled injection molding PP has high requirements on material performance, a matched thin-walled injection mold is needed, and the micro-foaming PP material has uncertainty in process and unstable product quality. Compared with the former two, the low-density PP has the advantages of simple process, low equipment requirement and capability of directly replacing high-density PP for application without changing the existing equipment.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a low-density and low-shrinkage polypropylene composite material and a preparation method thereof.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a polypropylene composite material comprises the following components in percentage by mass: 50-75% of polypropylene, 5-20% of low-density polyethylene, 5-15% of a toughening agent, 4-12% of a filler, 3-8% of glass fiber powder, 0.3-1% of a stabilizer and 0.2-2% of a lubricant.
The low-density polyethylene is the lightest variety of polyethylene resin, has good flexibility, extensibility and easy processability, has good chemical stability, and is alkali-resistant and common organic solvent; the glass fiber powder and the filler are beneficial to increasing the hardness and the compressive strength of the polypropylene product and reducing the shrinkage rate. The applicant of the invention selects the proportion of the low-density polyethylene, the flexibilizer, the filler and the glass fiber powder, so that the material keeps good rigidity and toughness balance, the polypropylene composite material with good mechanical properties such as tensile strength, bending strength and impact strength is prepared, and the shrinkage rate is low.
Preferably, the polypropylene composite material comprises the following components in percentage by mass: 52-70% of polypropylene, 8-18% of low-density polyethylene, 6-13% of a toughening agent, 6.7-11% of a filler, 5-8% of glass fiber powder, 0.4-0.8% of a stabilizer and 0.3-1.5% of a lubricant.
Preferably, the polypropylene composite material comprises the following components in percentage by mass: 68% of polypropylene, 9% of low-density polyethylene, 7% of a toughening agent, 7% of a filler, 8% of glass fiber powder, 0.6% of a stabilizer and 0.4% of a lubricant. Experiments prove that the polypropylene composite material prepared according to the proportion has the optimal comprehensive performance.
Preferably, the length-diameter ratio of the glass fiber powder is 10-50: 1. The length-diameter ratios of the glass fiber powder are different, and the mechanical properties are different, so that the applicant selects the length-diameter ratios of the glass fiber powder, so that the prepared polypropylene has proper toughness and good tensile strength.
Preferably, the melt flow rate (MI) of the polypropylene under the test conditions of 230 ℃ and 2.16kg is 5-100 g/10 min; the melt flow rate of the low-density polyethylene is more than or equal to 1g/10min at 190 ℃ under the test condition of 2.16 kg; the toughening agent comprises at least one of ethylene-butene copolymer, ethylene-octene copolymer, propylene-based elastomer; the filler comprises at least one of talcum powder, white carbon black, silicon dioxide, mica and wollastonite; the stabilizer comprises at least one of hindered phenol heat stabilizer, phosphite heat stabilizer and hindered amine light stabilizer; the lubricant comprises at least one of calcium stearate, PE wax, zinc stearate, ethylene bis stearamide and erucamide.
Preferably, the melt flow rate of the polypropylene under the test conditions of 230 ℃ and 2.16kg is 10-60 g/10 min.
Preferably, the stabilizer is a compound of a hindered phenol heat stabilizer, a phosphite heat stabilizer and a hindered amine light stabilizer; the mass ratio of each component in the compound is as follows: hindered phenol heat stabilizer: phosphite heat stabilizer: hindered amine light stabilizer ═ 1: 2: 3. the addition of the stabilizer can effectively delay the oxidation process of the material and achieve the effect of prolonging the service life.
Preferably, the hindered phenolic heat stabilizer is selected from at least one of heat stabilizers 1010, 1076; the phosphite ester heat stabilizer is selected from at least one of heat stabilizers 168 and 626; the hindered amine light stabilizer is selected from at least one of light stabilizers UV3808, V9900 and UV 783.
Preferably, the lubricant is a blend of calcium stearate and PE wax; the mass ratio of the calcium stearate to the PE wax in the compound is 1: 1. The addition of the lubricant can effectively reduce the heat loss of the material in the processing process and the thermal degradation of the material.
Preferably, the filler is talcum powder, and the mesh number of the talcum powder is 2500-3500.
Meanwhile, the invention also discloses a preparation method of the polypropylene composite material, which comprises the following steps:
(1) mixing polypropylene, low-density polyethylene and a toughening agent, and uniformly stirring to obtain a mixture A;
(2) adding a stabilizer and a lubricant into the mixture A, and uniformly stirring to obtain a mixture B;
(3) mixing glass fiber powder and a filler, and uniformly stirring to obtain a mixture C;
(4) and adding the mixture B into a main feeding port of a double-screw extruder, adding the mixture C into a side feeding port of the double-screw extruder, carrying out melt blending under the protection of inert gas or nitrogen, and finally carrying out extrusion granulation through the double-screw extruder to obtain the polypropylene composite material.
Preferably, in the steps (1) to (2), the stirring speed is 800-1500 rpm, and the stirring time is 3-10 min; in the step (3), the stirring speed is 500-1000 rpm, and the stirring time is 2-5 min; in the step (4), the length-diameter ratio of the screw is 40-50: 1, the rotating speed of a screw is 200-500 rpm, and the melt blending temperature is 190-230 ℃.
Compared with the prior art, the invention has the beneficial effects that: according to the invention, polypropylene is selected as a base material, and under the synergistic effect of low-density polyethylene, glass fiber powder and a filler, the use requirements of related parts are met, and the lightweight goal of the material is realized. The prepared polypropylene composite material has the characteristics of low density and low shrinkage; under the synergistic effect of the low-density polyethylene and the toughening agent, the polypropylene is simultaneously added with the compound agent and the glass fiber powder, so that the material keeps good rigidity and toughness balance, and the application range of the material is expanded. The preparation method disclosed by the invention is simple, the raw materials are easily available, the process operation is simple, and the method is easy to implement.
Detailed Description
To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.
Examples 1 to 5
In the embodiments of the polypropylene composite material of the present invention, the formula of the polypropylene composite material of embodiments 1 to 5 is shown in table 1, and the preparation method includes the following steps:
(1) mixing polypropylene, low-density polyethylene (LDPE) and a toughening agent, and stirring at 1000rpm for 5min to obtain a mixture A;
(2) adding a stabilizer and a lubricant into the mixture A, and stirring at 1000rpm for 5min to obtain a mixture B;
(3) mixing glass fiber powder and a filler, and stirring at 800rpm for 3min to obtain a mixture C;
(4) and adding the mixture B into a main feeding port of a double-screw extruder, adding the mixture C into a side feeding port of the double-screw extruder, wherein the length-diameter ratio of the double-screw extruder is 44:1, the rotating speed of a screw is 300rpm, carrying out melt blending under the protection of inert gas or nitrogen at the temperature of 200 ℃, and finally carrying out extrusion granulation through the double-screw extruder to obtain the polypropylene composite material.
Comparative example 1
The formula of the polypropylene composite material is shown in Table 1, and the preparation method is the same as that of the examples 1-5.
TABLE 1 formulation tables (wt.%) of examples 1 to 5 and comparative example 1
The raw materials used in table 1 are illustrated below:
polypropylene: copolymerized polypropylene BH975MO, MI of 38g/10min (230 ℃/2.16kg), flexural modulus of 1400MPa, northern Europe chemical engineering; the copolymerized polypropylene K9026 has MI of 26g/10min (230 ℃/2.16kg) and notch impact strength of 56KJ/m2The medium petrochemical industry; the proportion ratio of the two is 4: 1.
Low density polyethylene: LDPE DFDA-7042 with MI of 1.9g/10min (190 deg.C, 2.16kg), medium petrochemical;
a toughening agent: POE ExactTM8150, MI of 0.5g/10min (190 deg.C/2.16 kg), Exxon Mobil;
filling agent: talc powder BHS-1250A, Asahon powder materials Limited, Quanzhou;
glass fiber powder: XGFA1150, 11um glass fiber diameter, 300um average glass fiber length, Shenzhen Ninju Nippon high tech.
A stabilizer: the heat stabilizer 1010, the heat stabilizer 168 and the light stabilizer UV3808 are mixed in a mass ratio of 1: 2: 3;
lubricant: the composite material comprises calcium stearate and PE wax in a mass ratio of 1: 1.
Comparative example 2
A polypropylene composite material with the density of 0.93g/cm2Medium density polyethylene in alternative example 3The rest of the formulation and the preparation method of the low density polyethylene of (3) are the same as those of example 3.
Comparative example 3
Compared with the example 3, the polypropylene composite material does not contain glass fiber powder, the mass percent of the filler is 15%, and the rest formula and the preparation method are the same as the example 3.
Comparative example 4
Compared with the example 3, the polypropylene composite material does not contain low-density polyethylene, the mass percent of the polypropylene is 77%, and the rest formula and the preparation method are the same as the example 3.
Comparative example 5
Compared with the example 3, the polypropylene composite material does not contain low-density polyethylene and glass fiber powder, the mass percent of the polypropylene is 85%, and the rest formula and the preparation method are the same as the example 3.
Comparative example 6
Compared with the example 3, the polypropylene composite material does not contain low-density polyethylene and glass fiber powder, the mass percent of polypropylene is 72 percent, the mass percent of filler is 20 percent, and the rest formula and the preparation method are the same as the example 3.
Performance testing
The performance tests of examples 1 to 5 and comparative examples 1 to 6 were carried out, and the test criteria of each index are as follows, and the test results are shown in table 2.
And (4) testing standard:
tensile strength: GB/T1040.1-2006;
bending strength: GB/T9341-2008;
flexural modulus: GB/T9341-2008;
notched izod impact strength: GB/T1843-2008;
shrinkage rate: GB/T15585-1995.
Table 2 results of performance testing
From the above examples and comparative performance test data, it can be seen that the addition of the glass fiber powder and the low density polyethylene can effectively improve the shrinkage rate of the material, achieve the effect of less filling and low shrinkage, and at the same time, the addition of the glass fiber can effectively enhance the modulus of the material. The low-density polyethylene and the toughening agent are matched to effectively improve the toughness of the material. From this, it is understood that the weight reduction of the material can be achieved by using polypropylene as a base material and by synergistically modifying the low-density polyethylene, the glass fiber powder and the filler.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (10)
1. The polypropylene composite material is characterized by comprising the following components in percentage by mass: 50-75% of polypropylene, 5-20% of low-density polyethylene, 5-15% of a toughening agent, 4-12% of a filler, 3-8% of glass fiber powder, 0.3-1% of a stabilizer and 0.2-2% of a lubricant.
2. The polypropylene composite according to claim 1, comprising the following components in mass fraction: 52-70% of polypropylene, 8-18% of low-density polyethylene, 6-13% of a toughening agent, 6.7-11% of a filler, 5-8% of glass fiber powder, 0.4-0.8% of a stabilizer and 0.3-1.5% of a lubricant.
3. The polypropylene composite according to claim 1, comprising the following components in mass fraction: 68% of polypropylene, 9% of low-density polyethylene, 7% of a toughening agent, 7% of a filler, 8% of glass fiber powder, 0.6% of a stabilizer and 0.4% of a lubricant.
4. The polypropylene composite material according to any one of claims 1 to 3, wherein the glass fiber powder has an aspect ratio of 10 to 50: 1.
5. the polypropylene composite according to any one of claims 1 to 3, wherein the polypropylene has a melt flow rate of 5 to 100g/10min at 230 ℃ under a test condition of 2.16 kg; the melt flow rate of the low-density polyethylene is more than or equal to 1g/10min at 190 ℃ under the test condition of 2.16 kg; the toughening agent comprises at least one of ethylene-butene copolymer, ethylene-octene copolymer, propylene-based elastomer; the filler comprises at least one of talcum powder, white carbon black, silicon dioxide, mica and wollastonite; the stabilizer comprises at least one of hindered phenol heat stabilizer, phosphite heat stabilizer and hindered amine light stabilizer; the lubricant comprises at least one of calcium stearate, PE wax, zinc stearate, ethylene bis stearamide and erucamide.
6. The polypropylene composite of claim 5, wherein the stabilizer is a combination of a hindered phenol heat stabilizer, a phosphite heat stabilizer and a hindered amine light stabilizer; the mass ratio of each component in the compound is as follows: hindered phenol heat stabilizer: phosphite heat stabilizer: hindered amine light stabilizer ═ 1: 2: 3.
7. the polypropylene composite of claim 5, wherein the lubricant is a blend of calcium stearate and PE wax; the mass ratio of the calcium stearate to the PE wax in the compound is 1: 1.
8. The polypropylene composite material of claim 5, wherein the filler is talc, and the mesh number of the talc is 2500 to 3500.
9. A method for preparing a polypropylene composite material according to any one of claims 1 to 8, comprising the steps of:
(1) mixing polypropylene, low-density polyethylene and a toughening agent, and uniformly stirring to obtain a mixture A;
(2) adding a stabilizer and a lubricant into the mixture A, and uniformly stirring to obtain a mixture B;
(3) mixing glass fiber powder and a filler, and uniformly stirring to obtain a mixture C;
(4) and adding the mixture B into a main feeding port of a double-screw extruder, adding the mixture C into a side feeding port of the double-screw extruder, carrying out melt blending under the protection of inert gas or nitrogen, and finally carrying out extrusion granulation through the double-screw extruder to obtain the polypropylene composite material.
10. The method for preparing the polypropylene composite material according to claim 9, wherein in the steps (1) to (2), the stirring speed is 800 to 1500rpm, and the stirring time is 3 to 10 min; in the step (3), the stirring speed is 500-1000 rpm, and the stirring time is 2-5 min; in the step (4), the length-diameter ratio of the screw is 40-50: 1, the rotating speed of a screw is 200-500 rpm, and the melt blending temperature is 190-230 ℃.
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| CN202011392689.9A CN112480552A (en) | 2020-12-02 | 2020-12-02 | Polypropylene composite material and preparation method thereof |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115073851A (en) * | 2022-03-31 | 2022-09-20 | 金发科技股份有限公司 | Polypropylene composite material and preparation method and application thereof |
| CN117004139A (en) * | 2023-08-22 | 2023-11-07 | 苏州创扬新材料科技股份有限公司 | Low-hardness high-impact-resistance polypropylene material, preparation method thereof and BFS (bidirectional fluid infusion) plastic cover |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105273299A (en) * | 2014-06-06 | 2016-01-27 | 中国石油化工股份有限公司 | Isotropic low-shrinkage antibiotic and mildew-resistant polypropylene resin and preparation method thereof |
| CN105273301A (en) * | 2014-06-06 | 2016-01-27 | 中国石油化工股份有限公司 | Low-shrinkage polypropylene composite material and preparation method thereof |
-
2020
- 2020-12-02 CN CN202011392689.9A patent/CN112480552A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105273299A (en) * | 2014-06-06 | 2016-01-27 | 中国石油化工股份有限公司 | Isotropic low-shrinkage antibiotic and mildew-resistant polypropylene resin and preparation method thereof |
| CN105273301A (en) * | 2014-06-06 | 2016-01-27 | 中国石油化工股份有限公司 | Low-shrinkage polypropylene composite material and preparation method thereof |
Non-Patent Citations (3)
| Title |
|---|
| 王澜等: "《高分子材料》", 31 January 2009, 中国轻工业出版社 * |
| 翁祖祺等: "《中国玻璃钢工业大全》", 28 February 1992, 国防工业出版社 * |
| 谢荣化: "《塑料购销手册》", 30 May 1994, 中国物资出版社 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115073851A (en) * | 2022-03-31 | 2022-09-20 | 金发科技股份有限公司 | Polypropylene composite material and preparation method and application thereof |
| CN117004139A (en) * | 2023-08-22 | 2023-11-07 | 苏州创扬新材料科技股份有限公司 | Low-hardness high-impact-resistance polypropylene material, preparation method thereof and BFS (bidirectional fluid infusion) plastic cover |
| CN117004139B (en) * | 2023-08-22 | 2024-02-27 | 苏州创扬新材料科技股份有限公司 | Low-hardness high-impact-resistance polypropylene material, preparation method thereof and BFS (bidirectional fluid infusion) plastic cover |
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