A high temperature aging resistant polypropylene composition and preparation method thereof

Abstract

The present invention relates to the field of modified plastics technology, and more particularly to a high-temperature aging-resistant polypropylene composition and its preparation method. Specifically, the composition comprises, by weight, 70-90 parts of polypropylene, 30-40 parts of a thermoplastic elastomer, 5-15 parts of linear low-density polyethylene, 5-15 parts of polypropylene grafted with maleic anhydride, and 1-10 parts of stearic acid-modified calcium carbonate. By further modifying the calcium carbonate, the composition exhibits improved impact strength and tensile strength when combined with polypropylene, linear low-density polyethylene, polypropylene grafted with maleic anhydride, and thermoplastic elastomer, while also improving its high-temperature aging resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of modified plastics, in particular to a high-temperature aging-resistant polypropylene composition and a preparation method thereof. Background Art

[0002] Engineering materials have always occupied a pivotal position in the industrial field, thanks to their many outstanding properties. They are generally high-strength and can withstand enormous pressure and tension under various harsh working conditions, ensuring the stability and reliability of the structure. At the same time, the lightweight characteristics of engineering materials greatly reduce the overall weight during application, which is particularly important for some fields with strict weight restrictions, such as aerospace and automobile manufacturing. It is not only easy to install and transport, but also can effectively reduce energy consumption and improve energy efficiency. In addition, engineering materials also have excellent corrosion resistance and can maintain good performance in various chemical substances, harsh climates and other environments. They are not easily corroded, oxidized or damaged, thereby extending their service life and reducing maintenance and replacement costs. The advantage of its high cost-effectiveness allows many companies to balance cost control and quality assurance when applying them on a large scale, promoting the efficient development of the entire industrial production.

[0003] In recent years, with China's strong advocacy of green development, various industries have been actively pursuing more environmentally friendly and sustainable development paths. In the wire rope industry, the trend of product iteration and upgrading has become increasingly evident. Traditional wire ropes suffer from oil shedding during use, which not only pollutes the environment but also poses a potential threat to the health of operators. To address this issue and extend product lifespan, clad wire ropes have emerged. This new type of wire rope utilizes a special material filled into the core to effectively reduce oil leakage and mitigate the risk of environmental pollution. However, in practical applications, conventional engineering plastics have been found to have some shortcomings when used as cladding materials. Their relatively low toughness makes them prone to cracking and breaking when subjected to external forces such as impact or repeated stretching, compromising the product's sealing properties and ultimately shortening its service life. Furthermore, conventional engineering plastics lack ideal wear resistance. Under the frequent friction and compression of the wire rope, the cladding layer easily wears away, exposing the inner wire rope, accelerating wear and fatigue, and ultimately leading to premature product failure. This premature failure not only causes inconvenience to production, such as production interruptions and equipment downtime, affecting production progress and efficiency, but also increases maintenance costs and wastes resources, hindering the company's sustainable development. At the same time, the increase in operating temperature also places higher demands on the material's high-temperature aging resistance. Summary of the Invention

[0004] To solve the problems existing in the prior art, the present invention aims to provide a high-temperature aging-resistant polypropylene composition and a preparation method thereof. The present invention is achieved through the following technical solutions:

[0005] A high-temperature aging-resistant polypropylene composition comprises, 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.

[0006] Furthermore, the preparation method of the 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.

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

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

[0009] Furthermore, 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] Furthermore, the mixed solution is heated to 85° C. and maintained at 85° C. for 1 hour.

[0011] Furthermore, the temperature of the solution after adding stearic acid and reacting for 1 hour is 85°C.

[0012] The present application also provides a method for preparing the high-temperature aging-resistant polypropylene composition, comprising the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding, and granulating to obtain the composition.

[0013] Furthermore, 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 high-temperature aging-resistant polypropylene composition and a preparation method thereof. The composition comprises, by weight, 70-90 parts of polypropylene, 30-40 parts of a thermoplastic elastomer, 5-15 parts of linear low-density polyethylene, 5-15 parts of polypropylene grafted with maleic anhydride, and 1-10 parts of stearic acid-modified calcium carbonate. By further modifying the calcium carbonate, the composition exhibits improved impact strength and tensile strength when used in combination with polypropylene, linear low-density polyethylene, polypropylene grafted with maleic anhydride, and thermoplastic elastomer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the SEM image of stearic acid modified calcium carbonate in Example 1. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0018] The titanate coupling agent used in the present invention is NDZ-201, CAS No. 67691-13-8. The polypropylene is K8003 from Zhejiang Petrochemical, the linear low-density polyethylene is 7050H from Zhenhai Refining and Chemical, and the polypropylene is grafted with maleic anhydride, with an average molecular weight of 5,000 to 10,000. The thermoplastic elastomer is Elexar EL-8431.

[0019] Example 1

[0020] A high-temperature aging-resistant polypropylene composition comprises, by weight, 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 high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

[0022] The preparation method of stearic acid modified calcium carbonate is as follows:

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

[0024] Example 2

[0025] A high-temperature aging-resistant polypropylene composition comprises, by weight, 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 high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

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

[0028] Example 3

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

[0030] A preparation method of a high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

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

[0032] Example 4

[0033] A high-temperature aging-resistant polypropylene composition comprises, by weight, 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 stearic acid-modified calcium carbonate.

[0034] A preparation method of a high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

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

[0036] Example 5

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

[0038] A preparation method of a high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

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

[0040] Example 6

[0041] A high-temperature aging-resistant polypropylene composition comprises, by weight, 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 stearic acid-modified calcium carbonate.

[0042] A preparation method of a high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

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

[0044] Example 7

[0045] A high-temperature aging-resistant polypropylene composition comprises, by weight, 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 stearic acid-modified calcium carbonate.

[0046] A preparation method of a high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

[0047] The preparation method of stearic acid 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 that unmodified calcium carbonate was used.

[0050] Specifically: a high temperature aging resistant polypropylene composition, comprising, by weight: 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, wherein the particle size of the calcium carbonate is 1250 mesh.

[0051] A preparation method of a high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride and calcium carbonate in parts by weight, melt-extruding at a temperature of 190°C, and granulating to obtain the composition.

[0052] Comparative Example 2

[0053] The difference between this comparative example and comparative example 1 is that KH550 modified calcium carbonate is used.

[0054] Specifically: a high temperature aging resistant polypropylene composition, comprising, by weight: 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 high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and KH550 modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

[0056] The preparation method of KH550 modified calcium carbonate is as follows: 3 g of 1250 mesh calcium carbonate is dispersed in 100 mL of deionized water to obtain a mixed solution, the mixed solution is heated to 85° C. while stirring, and the mixed solution is maintained at 85° C. for 1 hour; then 7 g of KH550 is added, and the reaction is continued at 85° C. for 1 hour; then, the mixture is filtered, the precipitate is washed with deionized water, and dried to obtain the obtained product.

[0057] Comparative Example 3

[0058] The difference between this comparative example and comparative example 1 is that a titanate coupling agent is used to modify calcium carbonate.

[0059] Specifically: a high temperature aging resistant polypropylene composition, comprising, by weight: 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 high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and titanate coupling agent modified calcium carbonate according to weight parts, melt-extruding at a temperature of 190°C, and granulating to obtain the composition.

[0061] The preparation method of calcium carbonate modified with a titanate coupling agent is as follows: 3 g of 1250 mesh calcium carbonate is dispersed in 100 mL of deionized water to obtain a mixed solution, the mixed solution is heated to 85° C. while stirring, and the mixed solution is maintained at 85° C. for 1 hour; then 7 g of a titanate coupling agent is added, and the reaction is continued at 85° C. for 1 hour; then, the mixture is filtered, the precipitate is washed with deionized water, and dried to obtain the product.

[0062] Comparative Example 4

[0063] A high-temperature aging-resistant polypropylene composition comprises, by weight, 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 stearic acid-modified calcium carbonate.

[0064] A preparation method of a high-temperature aging-resistant polypropylene composition comprises the following steps: mixing polypropylene, thermoplastic elastomer, linear low-density polyethylene, polypropylene grafted maleic anhydride, and stearic acid-modified calcium carbonate in parts by weight, melt-extruding at a temperature of 190° C., and granulating to obtain the composition.

[0065] The preparation method of stearic acid-modified calcium carbonate is as follows: 3 g of 2000 mesh calcium carbonate is dispersed in 100 mL of deionized water to obtain a mixed solution, the mixed solution is heated to 85° C. while stirring, and the mixed solution is maintained at 85° C. for 1 hour; then 7 g of stearic acid is added, and the reaction is continued at 85° C. for 1 hour; then, the mixture is filtered, the precipitate is washed with deionized water, and dried to obtain the obtained product.

[0066] Test Example 1

[0067] The polyolefin materials prepared in the examples and comparative examples were prepared into dumbbell-shaped splines, and tensile tests were performed according to GB / T 1040.2-2006 at a tensile rate of 100 mm / min. Impact tests were performed according to GB / T 1843-2008 with an impact energy of 4.4 J, a spline 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] The polyolefin materials obtained in the examples and comparative examples were prepared into dumbbell-shaped specimens, which were treated at 180° C. and 100-200 times / h for 168 h, and the tensile strength of the treated specimens was tested.

[0073] Table 2 High temperature aging resistance 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 volume-increasing effect, and improve the strength and toughness of composite materials. Under the combined effect of stearic acid-modified calcium carbonate, thermoplastic elastomer and polypropylene grafted maleic anhydride, the prepared modified plastic strength and toughness have shown a synergistic enhancement phenomenon. The nanomaterial obtained by stearic acid-modified 1250 mesh calcium carbonate can be more dispersed into the elastomer, improving the toughening effect of the elastomer, so improving the elongation at break. 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 above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0077] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to 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 composition 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; 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; The calcium carbonate particle size is 1250 mesh; The mass ratio of the calcium carbonate to stearic acid is 3:(7-10).

2. 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 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.

3. 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.

4. The high temperature aging resistant polypropylene composition according to claim 3, characterized in that The solution temperature when the stearic acid was added and reacted for 1 hour was 85°C.

5. 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 parts by weight, performing melt extrusion and granulating to obtain the product.

6. The method for preparing a high temperature aging resistant polypropylene composition according to claim 5, characterized in that: The melting temperature is 190°C.

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