Modified waste tire rubber powder, preparation method thereof and application of modified waste tire rubber powder in polypropylene

Abstract

The invention provides modified waste tire rubber powder, a preparation method thereof and application of the modified waste tire rubber powder in polypropylene, and belongs to the technical field of polymer processing modification. According to the invention, liquid polybutadiene, sulfur and polypropylene are adopted to modify the waste tire rubber powder at high temperature, and the liquid polybutadiene is grafted with polybutadiene and polypropylene on the surface of the rubber powder through sulfur under the action of high temperature and mechanical force by virtue of good fluidity and excellent compatibility with the waste tire rubber powder; the modified waste tire rubber powder solves the problem of poor compatibility between the waste tire rubber powder and a polypropylene matrix, so that the waste tire rubber powder filled polypropylene material has excellent impact resistance. The result of the embodiment shows that the notch impact strength of the modified waste tire rubber powder filled polypropylene material prepared by the invention is 9.9 kJ / m < 2 > or above.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer processing and modification, and particularly relates to a modified waste tire rubber powder, a preparation method thereof, and an application thereof in polypropylene. Background Art

[0002] Polypropylene (PP) is one of the most widely used general plastics at present. Due to its characteristics such as low density, excellent mechanical properties, high heat resistance and chemical resistance, good chemical stability, low price, and easy processing, it is widely used in fields such as automobiles, household appliances, food packaging, medical devices, and building pipes. However, polypropylene has poor toughness, which limits its application in some fields. At present, elastomers such as ethylene-propylene rubber and ethylene-octene copolymer are usually blended with polypropylene to improve its toughness. However, elastomers such as ethylene-propylene rubber and ethylene-octene copolymer are expensive, which greatly increases the cost of polypropylene composites.

[0003] Rubber powder is made by crushing waste rubber (such as waste tires, rubber products, and scraps and waste products generated during the production process), and it has significant cost advantages for toughening polypropylene. At present, the largest amount of waste tire rubber powder is used, but it is mainly composed of natural rubber, styrene-butadiene rubber, etc., and there are significant differences in the decomposition microstructure with polypropylene, resulting in poor compatibility between waste tire rubber powder and polypropylene and making it difficult to significantly improve the toughness of polypropylene materials. In the prior art, in order to improve the compatibility between waste tire rubber powder and polypropylene, the waste tire rubber powder is generally coated with liquid ethylene-propylene-diene monomer rubber, but the improvement effect is not obvious; or a reclamation agent is used to activate the waste tire rubber powder, and an initiator, maleic anhydride, divinylbenzene, etc. are further added for in-situ reaction with polypropylene, but it is easy to generate odors during the processing and the toughening effect still needs to be further improved. Therefore, how to further improve the compatibility between waste tire rubber powder and the matrix, and then improve the toughness of the composite material has become a difficult problem in the prior art. Summary of the Invention

[0004] The purpose of the present invention is to provide a modified waste tire rubber powder, a preparation method thereof, and an application thereof in polypropylene. The modified waste tire rubber powder prepared by the preparation method provided by the present invention has excellent compatibility with the polypropylene matrix, so that the polypropylene material has better toughness.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a preparation method of a modified waste tire rubber powder, comprising:

[0007] Mixing polypropylene, sulfur, waste tire rubber powder, and liquid polybutadiene, and performing a modification treatment to obtain a modified waste tire rubber powder; the temperature of the modification treatment is 160-230 °C.

[0008] Preferably, the number-average molecular weight of the liquid polybutadiene is 2,000 to 50,000 g / mol.

[0009] Preferably, the mesh number of the waste tire rubber powder is 40 to 200 meshes.

[0010] Preferably, the mass ratio of the polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is (0.5 - 5):(0.1 - 2):(1 - 50):(0.1 - 5).

[0011] Preferably, the time of the modification treatment is 10 to 120 min.

[0012] The present invention also provides a modified waste tire rubber powder prepared by the preparation method described in the above technical solution.

[0013] The present invention also provides an application of the modified waste tire rubber powder described in the above technical solution in polypropylene.

[0014] Preferably, the modified waste tire rubber powder and polypropylene are kneaded to obtain a high impact resistant waste tire rubber powder filled polypropylene material.

[0015] Preferably, the mass ratio of the modified waste tire rubber powder and polypropylene is (1 - 50):100.

[0016] Preferably, the temperature of the kneading is 160 - 230 °C, and the time of the kneading is 10 - 15 min.

[0017] The present invention provides a preparation method of a modified waste tire rubber powder, comprising: mixing polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene, and performing a modification treatment to obtain a modified waste tire rubber powder; the temperature of the modification treatment is 160 - 230 °C. The present invention uses liquid polybutadiene, sulfur and polypropylene to modify waste tire rubber powder at high temperature. Due to the good fluidity of liquid polybutadiene and its excellent compatibility with waste tire rubber powder, under the action of high temperature and mechanical force, polybutadiene and polypropylene are grafted onto the surface of the rubber powder through sulfur, obtaining a modified waste tire rubber powder, solving the problem of poor compatibility between waste tire rubber powder and polypropylene matrix, and making the waste tire rubber powder filled polypropylene material have excellent impact resistance. The results of the examples show that the notched impact strength of the polypropylene material filled with the modified waste tire rubber powder prepared by the present invention is above 9.9 kJ / m 2 Above. Specific Embodiments

[0018] The present invention provides a preparation method of a modified waste tire rubber powder, comprising:

[0019] Mix polypropylene, sulfur, waste tire rubber powder, and liquid polybutadiene, and conduct a modification treatment to obtain modified waste tire rubber powder; the temperature of the modification treatment is 160 - 230 °C.

[0020] Unless otherwise specified, the present invention has no special limitations on the sources of each component, and commercially available products well-known to those skilled in the art can be used.

[0021] In the present invention, the mesh number of the waste tire rubber powder is preferably 40 - 200 meshes. As an implementation manner, the mesh number of the waste tire rubber powder can specifically be 40 meshes, 60 meshes, 70 meshes, 80 meshes, 90 meshes, 100 meshes, 170 meshes, or 200 meshes. By controlling the mesh number of the waste tire rubber powder within the above range in the present invention, it can be better mixed with the polypropylene matrix, further improving the toughness of the polypropylene material filled with waste tire rubber powder.

[0022] In the present invention, the number-average molecular weight of the liquid polybutadiene is preferably 2000 - 50000 g / mol. As an implementation manner, the number-average molecular weight of the liquid polybutadiene can specifically be 2000 g / mol, 5000 g / mol, 8000 g / mol, 10000 g / mol, 15000 g / mol, 20000 g / mol, 25000 g / mol, 30000 g / mol, 35000 g / mol, 40000 g / mol, 45000 g / mol, or 50000 g / mol. By controlling the molecular weight of the liquid polybutadiene within the above range in the present invention, it can have better fluidity and compatibility with the rubber powder, further improving the toughness of the polypropylene material filled with waste tire rubber powder.

[0023] In the present invention, the mass ratio of polypropylene, sulfur, waste tire rubber powder, and liquid polybutadiene is preferably (0.5 - 5) : (0.1 - 2) : (1 - 50) : (0.1 - 5). As an implementation manner, the mass ratio of polypropylene, sulfur, waste tire rubber powder, and liquid polybutadiene can specifically be 3.6 : 0.4 : 11.7 : 1, 3.6 : 0.4 : 11.7 : 2, 3.6 : 0.4 : 9 : 2, 3.6 : 0.8 : 9 : 0.25, 3.6 : 0.8 : 10.4 : 2, 3.6 : 0.8 : 10.4 : 3.5, 3.6 : 0.4 : 11.7 : 1, 1.1 : 1 : 11.7 : 1.5, or 0.5 : 0.4 : 12.4 : 1. By controlling the mass ratio of polypropylene, sulfur, waste tire rubber powder, and liquid polybutadiene within the above range in the present invention, more polybutadiene and polypropylene can be grafted onto the surface of the waste tire rubber powder, further improving the compatibility between the modified waste tire rubber powder and the polypropylene matrix, thereby further improving the toughness of the polypropylene material filled with waste tire rubber powder.

[0024] In the present invention, the mixing of the polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is preferably as follows: mix the polypropylene and sulfur at 160 - 230°C for 3 - 6 min, and then successively add the waste tire rubber powder and the liquid polybutadiene. In the present invention, the mixing is preferably carried out in a mixer. The present invention has no special limitation on the model of the mixer, and any commercially available model well-known to those skilled in the art can be used.

[0025] In the present invention, the temperature of the modification treatment is 160 - 230°C. As an embodiment, the temperature of the modification treatment can specifically be 160°C, 165°C, 170°C, 175°C, 180°C, 190°C, 200°C, 210°C, 220°C or 230°C.

[0026] In the present invention, the time of the modification treatment is preferably 10 - 120 min. As an embodiment, the time of the modification treatment can specifically be 10 min, 30 min, 50 min, 80 min, 100 min or 120 min. In the present invention, the modification treatment is preferably carried out in a mixer. By controlling the temperature and time of the modification treatment within the above ranges in the present invention, more polybutadiene and polypropylene can be grafted onto the surface of the waste tire rubber powder, further improving the compatibility between the modified waste tire rubber powder and the polypropylene matrix, and thus further enhancing the toughness of the polypropylene material filled with the modified waste tire rubber powder.

[0027] The present invention also provides a modified waste tire rubber powder prepared by the preparation method described in the above technical solution.

[0028] The modified waste tire rubber powder prepared by the present invention has excellent compatibility with the polypropylene matrix.

[0029] The present invention also provides the application of the modified waste tire rubber powder described in the above technical solution in polypropylene.

[0030] The present invention preferably kneads the modified waste tire rubber powder and polypropylene to obtain a polypropylene material filled with high impact-resistant waste tire rubber powder.

[0031] In the present invention, the mass ratio of the modified waste tire rubber powder to polypropylene is preferably (1 - 50):100. As an embodiment, the mass ratio of the modified waste tire rubber powder to polypropylene can specifically be 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, 40:100 or 50:87. By controlling the mass ratio of the modified waste tire rubber powder to polypropylene within the above ranges in the present invention, the toughness of the polypropylene material filled with the waste tire rubber powder can be further improved.

[0032] In the present invention, the temperature of the mixing is preferably 160 to 230 °C. As an embodiment, the temperature of the mixing can specifically be 160 °C, 165 °C, 170 °C, 175 °C, 180 °C, 190 °C, 200 °C, 210 °C, 220 °C or 230 °C.

[0033] In the present invention, the time of the mixing is preferably 10 to 15 min. As an embodiment, the time of the mixing can specifically be 10 min, 11 min, 12 min, 13 min, 14 min or 15 min.

[0034] In the present invention, the rotation speed of the mixing is preferably 50 to 80 rpm. As an embodiment, the rotation speed of the mixing can specifically be 50 rpm, 60 rpm, 70 rpm or 80 rpm. In the present invention, the mixing is preferably carried out in a Banbury mixer. By controlling the temperature and time of the mixing within the above ranges, the toughness of the waste tire rubber powder filled polypropylene material can be further improved.

[0035] The present invention uses liquid polybutadiene, sulfur and polypropylene to modify waste tire rubber powder at high temperature. Due to its good fluidity and excellent compatibility with waste tire rubber powder, liquid polybutadiene grafts polybutadiene and polypropylene on the surface of the rubber powder through sulfur under the action of high temperature and mechanical force, obtaining modified waste tire rubber powder, solving the problem of poor compatibility between waste tire rubber powder and polypropylene matrix, and making the waste tire rubber powder filled polypropylene material have excellent impact resistance.

[0036] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts belong to the scope of protection of the present invention.

[0037] In the examples and comparative examples, the polypropylene is from Sinopec Yanshan Petrochemical Company, with the grade of 3204; the waste tire rubber powder is provided by Zhongjiao Weiye (Shandong) Rubber Co., Ltd.; the liquid polybutadiene is provided by Shanghai Guguanglong Trading Co., Ltd., with the model of PPLPB142K, and the number average molecular weight of the liquid polybutadiene is 5000 g / mol; the sulfur is provided by Ruiba New Materials Group.

[0038] Example 1

[0039] A preparation method of modified waste tire rubber powder: Mix 3.6 g of polypropylene and 0.4 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min. Then add 11.7 g of waste tire rubber powder (120 mesh) and 1 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 3.6:0.4:11.7:1), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0040] Application Example 1

[0041] A preparation method of a high impact resistant waste tire rubber powder filled polypropylene material: Add 87 g of polypropylene (the mass ratio of modified waste tire rubber powder to polypropylene is 19.2:100) to 16.7 g of the modified waste tire rubber powder prepared in Example 1, and mix at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0042] Example 2

[0043] A preparation method of modified waste tire rubber powder: Mix 3.6 g of polypropylene and 0.4 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min. Then add 11.7 g of waste tire rubber powder (120 mesh) and 2 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 3.6:0.4:11.7:2), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0044] Application Example 2

[0045] A preparation method of a high impact resistant waste tire rubber powder filled polypropylene material: Add 87 g of polypropylene (the mass ratio of modified waste tire rubber powder to polypropylene is 20.3:100) to 17.7 g of the modified waste tire rubber powder prepared in Example 2, and mix at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0046] Example 3

[0047] A preparation method of modified waste tire rubber powder: Mix 3.6 g of polypropylene and 0.4 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min. Then add 9 g of waste tire rubber powder (80 mesh) and 2 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 3.6:0.4:9:2), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0048] Application Example 3

[0049] Preparation method of a high impact-resistant waste tire rubber powder-filled polypropylene material: Add 87 g of polypropylene to 15 g of the modified waste tire rubber powder prepared in Example 3 (the mass ratio of the modified waste tire rubber powder to polypropylene is 17.2:100), and knead at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder-filled polypropylene material.

[0050] Example 4

[0051] Preparation method of a modified waste tire rubber powder: Mix 3.6 g of polypropylene and 0.8 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min, then add 9 g of waste tire rubber powder (100 mesh) and 0.25 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 3.6:0.8:9:0.25), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0052] Application Example 4

[0053] Preparation method of a high impact-resistant waste tire rubber powder-filled polypropylene material: Add 87 g of polypropylene to 13.65 g of the modified waste tire rubber powder prepared in Example 4 (the mass ratio of the modified waste tire rubber powder to polypropylene is 15.7:100), and knead at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder-filled polypropylene material.

[0054] Example 5

[0055] Preparation method of a modified waste tire rubber powder: Mix 3.6 g of polypropylene and 0.8 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min, then add 10.4 g of waste tire rubber powder (80 mesh) and 2 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 3.6:0.8:10.4:2), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0056] Application Example 5

[0057] Preparation method of a high impact-resistant waste tire rubber powder-filled polypropylene material: Add 87 g of polypropylene to 16.8 g of the modified waste tire rubber powder prepared in Example 5 (the mass ratio of the modified waste tire rubber powder to polypropylene is 19.3:100), and knead at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder-filled polypropylene material.

[0058] Example 6

[0059] A preparation method of modified waste tire rubber powder: Mix 3.6 g of polypropylene and 0.8 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min. Then add 10.4 g of waste tire rubber powder (80 mesh) and 3.5 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 3.6:0.8:10.4:3.5), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0060] Application Example 6

[0061] A preparation method of a high impact resistant waste tire rubber powder filled polypropylene material: Add 87 g of polypropylene (the mass ratio of modified waste tire rubber powder to polypropylene is 21:100) to 18.3 g of the modified waste tire rubber powder prepared in Example 6, and knead at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0062] Example 7

[0063] A preparation method of modified waste tire rubber powder: Mix 3.6 g of polypropylene and 0.4 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min. Then add 11.7 g of waste tire rubber powder (60 mesh) and 1 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 3.6:0.4:11.7:1), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0064] Application Example 7

[0065] A preparation method of a high impact resistant waste tire rubber powder filled polypropylene material: Add 87 g of polypropylene (the mass ratio of modified waste tire rubber powder to polypropylene is 19.2:100) to 16.7 g of the modified waste tire rubber powder prepared in Example 7, and knead at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0066] Example 8

[0067] A preparation method of modified waste tire rubber powder: Mix 1.1 g of polypropylene and 0.1 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min. Then add 11.7 g of waste tire rubber powder (80 mesh) and 1.5 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 1.1:0.1:11.7:1.5), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0068] Application Example 8

[0069] Preparation method of a high impact-resistant waste tire rubber powder filled polypropylene material: Add 87 g of polypropylene to 14.4 g of the modified waste tire rubber powder prepared in Example 8 (the mass ratio of the modified waste tire rubber powder to polypropylene is 16.6:100), and mix at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0070] Example 9

[0071] Preparation method of a modified waste tire rubber powder: Mix 0.5 g of polypropylene and 0.4 g of sulfur in a mixer at 170 °C and 70 rpm for 5 min, then add 12.4 g of waste tire rubber powder (80 mesh) and 1 g of liquid polybutadiene (the mass ratio of polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is 0.5:0.4:12.4:1), and continue to mix for 15 min to obtain the modified waste tire rubber powder.

[0072] Application Example 9

[0073] Preparation method of a high impact-resistant waste tire rubber powder filled polypropylene material: Add 87 g of polypropylene to 14.3 g of the modified waste tire rubber powder prepared in Example 9 (the mass ratio of the modified waste tire rubber powder to polypropylene is 16.4:100), and mix at 170 °C and 70 rpm for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0074] Comparative Example 1

[0075] Mix 87 g of polypropylene in a mixer at 170 °C and 70 rpm for 12 min to obtain the polypropylene material.

[0076] Comparative Example 2

[0077] Mix 11.7 g of waste tire rubber powder (120 mesh) and 3.6 g of polypropylene in a mixer at 170 °C and 70 rpm for 20 min, then add 87 g of polypropylene and continue to mix for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0078] Comparative Example 3

[0079] Mix 9 g of waste tire rubber powder (120 mesh), 0.4 g of sulfur and 3.6 g of polypropylene in a mixer at 170 °C and 70 rpm for 20 min, then add 87 g of polypropylene and continue to mix for 12 min to obtain the waste tire rubber powder filled polypropylene material.

[0080] Comparative Example 4

[0081] Mix 9 g of waste tire rubber powder (120 mesh), 0.8 g of liquid polybutadiene, and 3.6 g of polypropylene in a mixer at 170 °C and 70 rpm for 20 min. Then add 87 g of polypropylene and continue mixing for 12 min to obtain a polypropylene material filled with waste tire rubber powder.

[0082] Comparative Example 5

[0083] Mix 87 g of polypropylene and 13 g of POE8150 in a mixer at 170 °C and 70 rpm for 12 min to obtain a POE-filled polypropylene material.

[0084] Inject the polypropylene materials of Application Examples 1-9 and Comparative Examples 1-5 into standard specimens through an injection molding machine. The obtained standard specimens are tested for the notched Izod impact strength according to GB / T 1843-2008, and the test results are shown in Table 1.

[0085] Table 1 Notched Impact Strength of Polypropylene Materials in Application Examples 1-9 and Comparative Examples 1-5

[0086] Label <![CDATA[Notched impact strength (kJ / m 2 )]]> Comparative Example 1 6.2 Comparative Example 2 5.0 Comparative Example 3 5.9 Comparative Example 4 7.0 Comparative Example 5 17.3 Application Example 1 15.0 Application Example 2 18.9 Application Example 3 18.6 Application Example 4 9.9 Application Example 5 16.9 Application Example 6 10.5 Application Example 7 16.1 Application Example 8 13.7 Application Example 9 18.7

[0087] It can be seen from the data in Table 1 that: (1) By comparing the results of Comparative Example 3 and 4, it can be seen that using sulfur or liquid polybutadiene-modified rubber powder alone cannot significantly improve the notch impact resistance of polypropylene, indicating the limitations of a single modification method; (2) Compared with Comparative Examples 1-4, the application examples use sulfur and liquid polybutadiene rubber in combination to modify the rubber powder, and the effect of improving the notch impact resistance of the polypropylene material is obvious; (3) The notch impact resistance of the polypropylene materials in Application Examples 2, 3, and 9 is better than that of Comparative Example 5, which shows that the modified waste tire rubber powder exhibits the same toughening effect as the POE material, but the price of the modified waste tire rubber powder is much lower than that of POE, having an obvious economic advantage.

[0088] In summary, the polypropylene material filled with the modified waste tire rubber powder prepared by the present invention has excellent impact resistance.

[0089] The above are only the preferred embodiments 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 refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing modified waste tire rubber powder, comprising: The polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene are mixed and modified to obtain modified waste tire rubber powder; The temperature of the modification treatment is 160-230°C.

2. The preparation method according to claim 1, characterized in that: The number average molecular weight of the liquid polybutadiene is 2000-50000 g / mol.

3. The preparation method according to claim 1, characterized in that: The mesh size of the waste tire rubber powder is 40 to 200 meshes.

4. The preparation method according to claim 1, characterized in that: The mass ratio of the polypropylene, sulfur, waste tire rubber powder and liquid polybutadiene is (0.5-5): (0.1-2): (1-50): (0.1-5).

5. The preparation method according to claim 1, characterized in that: The modification treatment time is 10 to 120 minutes.

6. The modified waste tire rubber powder prepared by the preparation method according to any one of claims 1 to 5.

7. Application of the modified waste tire rubber powder according to claim 6 in polypropylene.

8. The use according to claim 7, characterized in that: The modified waste tire rubber powder is mixed with polypropylene to obtain a high impact-resistant waste tire rubber powder filled polypropylene material.

9. The use according to claim 8, characterized in that: The mass ratio of the modified waste tire rubber powder to polypropylene is (1-50):

100.

10. The use according to claim 8, characterized in that: The mixing temperature is 160-230° C., and the mixing time is 10-15 minutes.