High-temperature-aging-resistant polypropylene composition and preparation method thereof

Abstract

The invention relates to the technical field of modified plastics, in particular to a high-temperature-aging-resistant polypropylene composition and a preparation method thereof. Specifically, the material comprises the following components in parts by weight: 70-90 parts of polypropylene, 30-40 parts of thermoplastic elastomer, 5-15 parts of linear low-density polyethylene, 5-15 parts of polypropylene grafted maleic anhydride and 1-10 parts of stearic acid modified calcium carbonate. The calcium carbonate is further modified, so that the calcium carbonate has better impact strength and tensile strength when being compounded with polypropylene, linear low-density polyethylene, polypropylene grafted maleic anhydride and a thermoplastic elastomer, and meanwhile, the high-temperature aging resistance is also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of modified plastics, and particularly to a polypropylene composition with high heat aging resistance and a preparation method thereof. Background Art

[0002] Engineering materials have always occupied a crucial position in the industrial field, thanks to their many excellent properties. They usually have high strength and can withstand huge pressure and tensile force under various harsh working conditions, ensuring the stability and reliability of the structure. At the same time, the light weight of engineering materials greatly reduces the overall weight during application, which is particularly important for some fields with strict weight restrictions, such as aerospace and automotive manufacturing. It is not only convenient for installation and transportation but also can effectively reduce energy consumption and improve energy efficiency. In addition, engineering materials have excellent corrosion resistance and can maintain good performance in various environments such as various chemical substances and harsh climates. They are not easily eroded, oxidized or damaged, thus extending the service life and reducing maintenance and replacement costs. Moreover, the advantage of high cost performance enables many enterprises to balance cost control and quality assurance during large-scale application, promoting the efficient development of the entire industrial production.

[0003] In recent years, with the strong advocacy of the concept of green development by the state, all industries are actively seeking more environmentally friendly and sustainable development paths. In the wire rope industry, the trend of product iteration and upgrading is becoming increasingly obvious. Traditional wire ropes have the problem of oil splashing during use, which not only pollutes the environment but also may pose a potential threat to the health of operators. To solve this problem and improve the service life of products, filled and coated wire ropes have emerged. This new type of wire rope effectively reduces the leakage of grease and the risk of environmental pollution by filling special materials in the rope core. However, in practical applications, it is found that when ordinary engineering plastics are used as filled and coated materials, there are some deficiencies. Their toughness is relatively low, and when subjected to external forces such as impact or repeated stretching, they are prone to breakage, damage, etc., resulting in the damage of the product's sealing performance and thus affecting the service life. Moreover, the wear resistance of ordinary engineering plastics is not ideal. In the working environment where wire ropes are frequently rubbed and squeezed, the filled and coated layer is easily worn, exposing the internal wire ropes, accelerating the wear and fatigue of the wires, and ultimately leading to early failure of the product. This early failure not only brings inconvenience to production, such as production interruption and equipment shutdown, affecting production progress and efficiency, but also increases the enterprise's maintenance costs and resource waste, which is not conducive to the sustainable development of the enterprise. At the same time, with the increase in the use scenario temperature, higher requirements are also put forward for the high temperature aging resistance of materials. Summary of the Invention

[0004] To solve the problems existing in the prior art, the object of the present invention is to provide a polypropylene composition with high temperature aging resistance and its preparation method. The present invention is achieved through the following technical solutions:

[0005] A polypropylene composition with high temperature aging resistance, by weight, includes: 70 - 90 parts of polypropylene, 30 - 40 parts of thermoplastic elastomer, 5 - 15 parts of linear low density polyethylene, 5 - 15 parts of polypropylene grafted maleic anhydride, and 1 - 10 parts of calcium carbonate modified with stearic acid.

[0006] Further, the preparation method of the calcium carbonate modified with stearic acid is as follows: Take calcium carbonate and disperse it in deionized water to obtain a mixed solution, and heat the mixed solution while stirring; then add stearic acid and react for 1 h; then filter and wash the precipitate with deionized water.

[0007] Further, the particle size of the calcium carbonate is 1250 mesh.

[0008] Further, the mass ratio of the calcium carbonate to the stearic acid is 3:(7 - 10).

[0009] Further, the content of the polypropylene is 70 parts by weight, the thermoplastic elastomer is 30 parts by weight, the linear low density polyethylene is 10 parts by weight, and the polypropylene grafted maleic anhydride is 10 parts by weight.

[0010] Further, the temperature for heating the mixed solution is 85°C and the reaction is maintained at 85°C for 1 h.

[0011] Further, the solution temperature when reacting for 1 h after adding stearic acid is 85°C.

[0012] The present application also provides a preparation method of the polypropylene composition with high temperature aging resistance, including the following steps: Mix polypropylene, thermoplastic elastomer, linear low density polyethylene, polypropylene grafted maleic anhydride, and calcium carbonate modified with stearic acid according to the weight parts, then carry out melt extrusion, and after pelletizing, it is obtained.

[0013] Further, the melting temperature is 190°C.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0015] The present invention provides a polypropylene composition with high temperature aging resistance and its preparation method, by weight, including: 70 - 90 parts of polypropylene, 30 - 40 parts of thermoplastic elastomer, 5 - 15 parts of linear low density polyethylene, 5 - 15 parts of polypropylene grafted maleic anhydride, and 1 - 10 parts of calcium carbonate modified with stearic acid. Through further modification of calcium carbonate, it has better impact strength and tensile strength in the compound use with polypropylene, linear low density polyethylene, polypropylene grafted maleic anhydride, and thermoplastic elastomer. Brief Description of the Drawings

[0016] Figure 1 It is the SEM image of the stearic acid modified calcium carbonate in Example 1. Detailed Description of the Invention

[0017] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0018] In the present invention, the titanate coupling agent is NDZ-201, and the CAS number is 67691-13-8. The polypropylene is Zhejiang Petrochemical K8003; the linear low density polyethylene is Zhenhai Refining & Chemical 7050H; the polypropylene grafted maleic anhydride has an average molecular weight of 5000-10000. The thermoplastic elastomer is Elexar EL-8431.

[0019] Example 1

[0020] A polypropylene composition with high temperature aging resistance, by weight, includes: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 1 part of stearic acid modified calcium carbonate.

[0021] A preparation method of a polypropylene composition with high temperature aging resistance includes the following steps: Mix polypropylene, thermoplastic elastomer, linear low density polyethylene, polypropylene grafted maleic anhydride, and stearic acid modified calcium carbonate according to the weight parts, and then carry out melt extrusion at a temperature of 190°C. After pelletizing, it is obtained.

[0022] Among them, the preparation method of the stearic acid modified calcium carbonate is as follows:

[0023] Take 3 g of 1250-mesh calcium carbonate and disperse it in 100 mL of deionized water to obtain a mixed solution. While stirring, heat the mixed solution to 85°C and maintain the mixed solution at 85°C for 1 h; then add 7 g of stearic acid and continue to react at 85°C for 1 h; then filter, wash the precipitate with deionized water, and obtain it after drying. Figure 1 It is the SEM image (5 μm) of the stearic acid modified calcium carbonate in this example.

[0024] Example 2

[0025] A polypropylene composition with high temperature aging resistance, by weight, includes: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 2 parts of stearic acid modified calcium carbonate.

[0026] A preparation method of a polypropylene composition resistant to high-temperature aging comprises the following steps: Mix polypropylene, a thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and calcium carbonate modified with stearic acid according to parts by weight, and then perform melt extrusion at a temperature of 190°C. After pelletizing, the product is obtained.

[0027] The preparation method of the calcium carbonate modified with stearic acid is the same as that in Example 1.

[0028] Example 3

[0029] A polypropylene composition resistant to high-temperature aging comprises, by parts by weight: 70 parts of polypropylene, 30 parts of a thermoplastic elastomer, 10 parts of linear low-density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 3 parts of calcium carbonate modified with stearic acid.

[0030] A preparation method of a polypropylene composition resistant to high-temperature aging comprises the following steps: Mix polypropylene, a thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and calcium carbonate modified with stearic acid according to parts by weight, and then perform melt extrusion at a temperature of 190°C. After pelletizing, the product is obtained.

[0031] The preparation method of the calcium carbonate modified with stearic acid is the same as that in Example 1.

[0032] Example 4

[0033] A polypropylene composition resistant to high-temperature aging comprises, by parts by weight: 70 parts of polypropylene, 30 parts of a thermoplastic elastomer, 10 parts of linear low-density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 4 parts of calcium carbonate modified with stearic acid.

[0034] A preparation method of a polypropylene composition resistant to high-temperature aging comprises the following steps: Mix polypropylene, a thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and calcium carbonate modified with stearic acid according to parts by weight, and then perform melt extrusion at a temperature of 190°C. After pelletizing, the product is obtained.

[0035] The preparation method of the calcium carbonate modified with stearic acid is the same as that in Example 1.

[0036] Example 5

[0037] A polypropylene composition resistant to high-temperature aging comprises, by parts by weight: 70 parts of polypropylene, 30 parts of a thermoplastic elastomer, 10 parts of linear low-density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 5 parts of calcium carbonate modified with stearic acid.

[0038] A preparation method of a polypropylene composition resistant to high-temperature aging comprises the following steps: Mix polypropylene, a thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and calcium carbonate modified with stearic acid according to parts by weight, and then perform melt extrusion at a temperature of 190°C. After pelletizing, the product is obtained.

[0039] The preparation method of the calcium stearate modified calcium carbonate is the same as that in Example 1.

[0040] Example 6

[0041] A polypropylene composition with high temperature aging resistance, by weight, comprises: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 7 parts of calcium stearate modified calcium carbonate.

[0042] A preparation method of a polypropylene composition with high temperature aging resistance includes the following steps: Mix polypropylene, thermoplastic elastomer, linear low density polyethylene, polypropylene grafted maleic anhydride, and calcium stearate modified calcium carbonate according to the weight parts, and then carry out melt extrusion at a temperature of 190 °C, and granulate to obtain the product.

[0043] The preparation method of the calcium stearate modified calcium carbonate is the same as that in Example 1.

[0044] Example 7

[0045] A polypropylene composition with high temperature aging resistance, by weight, comprises: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 10 parts of calcium stearate modified calcium carbonate.

[0046] A preparation method of a polypropylene composition with high temperature aging resistance includes the following steps: Mix polypropylene, thermoplastic elastomer, linear low density polyethylene, polypropylene grafted maleic anhydride, and calcium stearate modified calcium carbonate according to the weight parts, and then carry out melt extrusion at a temperature of 190 °C, and granulate to obtain the product.

[0047] The preparation method of the calcium stearate modified calcium carbonate is the same as that in Example 1.

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 4 is the use of unmodified calcium carbonate.

[0050] Specifically: A polypropylene composition with high temperature aging resistance, by weight, comprises: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low density polyethylene, 10 parts of polypropylene grafted maleic anhydride, 4 parts of calcium carbonate, and the particle size of the calcium carbonate is 1250 mesh.

[0051] A preparation method of a polypropylene composition with high temperature aging resistance includes the following steps: Mix polypropylene, thermoplastic elastomer, linear low density polyethylene, polypropylene grafted maleic anhydride, and calcium carbonate according to the weight parts, and then carry out melt extrusion at a temperature of 190 °C, and granulate to obtain the product.

[0052] Comparative Example 2

[0053] The difference between this comparative example and Comparative Example 1 is the use of KH550-modified calcium carbonate.

[0054] Specifically: A polypropylene composition with high temperature aging resistance, by weight, includes: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 4 parts of KH550-modified calcium carbonate.

[0055] A preparation method of a polypropylene composition with high temperature aging resistance includes the following steps: After mixing polypropylene, thermoplastic elastomer, linear low density polyethylene, polypropylene grafted maleic anhydride, and KH550-modified calcium carbonate according to the weight parts, melt extrusion is carried out at a temperature of 190 °C, and after granulation, it is obtained.

[0056] The preparation method of KH550-modified calcium carbonate is as follows: Take 3 g of 1250-mesh calcium carbonate and disperse it into 100 mL of deionized water to obtain a mixed solution. While stirring, heat the mixed solution to 85 °C and maintain the mixed solution at 85 °C for 1 h; then add 7 g of KH550 and continue to react at 85 °C for 1 h; then filter, wash the precipitate with deionized water, and dry it to obtain.

[0057] Comparative Example 3

[0058] The difference between this comparative example and Comparative Example 1 is the use of titanate coupling agent-modified calcium carbonate.

[0059] Specifically: A polypropylene composition with high temperature aging resistance, by weight, includes: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 4 parts of titanate coupling agent-modified calcium carbonate.

[0060] A preparation method of a polypropylene composition with high temperature aging resistance includes the following steps: After mixing polypropylene, thermoplastic elastomer, linear low density polyethylene, polypropylene grafted maleic anhydride, and titanate coupling agent-modified calcium carbonate according to the weight parts, melt extrusion is carried out at a temperature of 190 °C, and after granulation, it is obtained.

[0061] The preparation method of titanate coupling agent-modified calcium carbonate is as follows: Take 3 g of 1250-mesh calcium carbonate and disperse it into 100 mL of deionized water to obtain a mixed solution. While stirring, heat the mixed solution to 85 °C and maintain the mixed solution at 85 °C for 1 h; then add 7 g of titanate coupling agent and continue to react at 85 °C for 1 h; then filter, wash the precipitate with deionized water, and dry it to obtain.

[0062] Comparative Example 4

[0063] A polypropylene composition resistant to high-temperature aging, by weight, includes: 70 parts of polypropylene, 30 parts of thermoplastic elastomer, 10 parts of linear low-density polyethylene, 10 parts of polypropylene grafted maleic anhydride, and 4 parts of calcium carbonate modified with stearic acid.

[0064] A preparation method of a polypropylene composition resistant to high-temperature aging includes the following steps: Mix polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and calcium carbonate modified with stearic acid according to the weight parts, and then carry out melt extrusion at a temperature of 190 °C. After pelletizing, it is obtained.

[0065] The preparation method of the calcium carbonate modified with stearic acid is as follows: Take 3 g of 2000-mesh calcium carbonate and disperse it into 100 mL of deionized water to obtain a mixed solution. While stirring, heat the mixed solution to 85 °C and maintain the mixed solution at 85 °C for 1 h; then add 7 g of stearic acid and continue to react at 85 °C for 1 h; then filter, wash the precipitate with deionized water, and dry it to obtain.

[0066] Test Example 1

[0067] Prepare the polyolefin materials prepared in the examples and comparative examples into dumbbell-shaped specimens, and carry out tensile tests with reference to GB / T 1040.2-2006, with a tensile rate of 100 mm / min; carry out impact tests with reference to the GB / T 1843-2008 standard, with an impact energy of 4.4 J, a specimen notch depth of 2 mm, and a test temperature of 25 °C; the specific test results are shown in Table 1.

[0068] Table 1 Performance test.

[0069]

[0070]

[0071] Test Example 2

[0072] Prepare the polyolefin materials prepared in the examples and comparative examples into dumbbell-shaped specimens, and process them under the conditions of 180 °C and a ventilation rate of 100-200 times / h for 168 h, and test the tensile strength of the processed specimens.

[0073] Table 2 High-temperature aging performance test

[0074]

[0075] As can be seen from Table 1, polypropylene grafted maleic anhydride can significantly improve the interfacial compatibility between polypropylene and thermoplastic elastomer, play a compatibilizing role, and enhance the strength and toughness of the composite material. Under the combined action of calcium carbonate modified with stearic acid, thermoplastic elastomer and polypropylene grafted maleic anhydride, the strength and toughness of the prepared modified plastic show a phenomenon of synergistic enhancement. The nanomaterials obtained from 1250-mesh calcium carbonate modified with stearic acid can be more dispersed in the elastomer, improving the toughening effect of the elastomer, so the elongation at break is increased. As can be seen from Table 2, polypropylene grafted maleic anhydride can also significantly improve the high-temperature aging resistance of the composition.

[0076] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0077] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high temperature aging resistant polypropylene composition, characterized in that: The invention comprises, by weight: 70 to 90 parts of polypropylene, 30 to 40 parts of thermoplastic elastomer, 5 to 15 parts of linear low-density polyethylene, 5 to 15 parts of polypropylene grafted maleic anhydride, and 1 to 10 parts of stearic acid-modified calcium carbonate.

2. The high temperature aging resistant polypropylene composition according to claim 1, characterized in that: The preparation method of stearic acid-modified calcium carbonate is as follows: calcium carbonate is dispersed in deionized water to obtain a mixed solution, and the mixed solution is heated while stirring; stearic acid is then added and reacted for 1 hour; and then filtered and the precipitate is washed with deionized water.

3. The high temperature aging resistant polypropylene composition according to claim 2, characterized in that: The calcium carbonate particle size is 1250 meshes.

4. The high temperature aging resistant polypropylene composition according to claim 2, characterized in that: The mass ratio of calcium carbonate to stearic acid is 3:(7-10).

5. The high temperature aging resistant polypropylene composition according to claim 1, characterized in that: The content of the polypropylene is 70 parts by weight, the content of the thermoplastic elastomer is 30 parts by weight, the content of the linear low-density polyethylene is 10 parts by weight, and the content of the polypropylene grafted maleic anhydride is 10 parts by weight.

6. The high temperature aging resistant polypropylene composition according to claim 2, characterized in that: The mixed solution was heated to 85° C. and maintained at 85° C. for 1 hour.

7. The high temperature aging resistant polypropylene composition according to claim 2, characterized in that: The solution temperature when the stearic acid was added and reacted for 1 hour was 85°C.

8. The method for preparing a high temperature aging resistant polypropylene composition according to claim 1, characterized in that: The method comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride and stearic acid modified calcium carbonate according to weight proportions, performing melt extrusion and granulating to obtain the product.

9. The method for preparing a high temperature aging resistant polypropylene composition according to claim 8, characterized in that: The melting temperature is 190°C.

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