CN117089139A

CN117089139A - Modified polypropylene composition

Info

Publication number: CN117089139A
Application number: CN202310999516.0A
Authority: CN
Inventors: 林行
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-08-09
Filing date: 2023-08-09
Publication date: 2023-11-21

Abstract

The application provides a modified polypropylene composition, and relates to the technical field of polypropylene. The modified polypropylene composition comprises the following raw materials in parts by weight: 100 parts of polypropylene, 0.5 to 10 parts of modified carbon nano-tubes and 0 to 5 parts of maleic anhydride grafted polyolefin. The modified carbon nanotube is prepared by reacting a prepolymer obtained by reacting long-chain alkyl glycol with diisocyanate with diamine to obtain a modifier, and reacting the modifier with the carbon nanotube. The modified carbon nano tube in the modified polypropylene composition provided by the application modifies long-chain alkyl and urea bonds and urethane bonds, and has better performance.

Description

Modified polypropylene composition

Technical Field

The application belongs to the technical field of polypropylene, and relates to a modified polypropylene composition.

Background

Polypropylene is a commonly used synthetic polymer and has a number of applications both in industry and civilian use. The carbon nanotubes, which are classified into single-walled carbon nanotubes SWNTs and multi-walled carbon nanotubes MWNTs, have many excellent properties, electrical conductivity, high strength, and the like. The carbon nanotubes are introduced into polypropylene, so that the polypropylene can be endowed with higher mechanical strength, excellent antistatic property and the like. However, since carbon nanotubes are nano-sized materials, dispersion in polypropylene is a problem, and the dispersibility affects the performance of carbon nanotubes.

Disclosure of Invention

The application aims to overcome the defects of the prior art and provides a modified polypropylene composition.

The technical scheme of the application is as follows:

the modified polypropylene composition comprises the following raw materials in parts by weight: 100 parts of polypropylene, 0.5-10 parts of modified carbon nano tube and 0-5 parts of maleic anhydride grafted polypropylene.

Preferably, the modified carbon nanotube is prepared as follows:

s1, reacting long-chain alkyl glycol with diisocyanate according to a molar ratio of 0.6-0.98:1 to obtain a prepolymer;

s2, diamine is added into the prepolymer in the step S1 for chain extension, and a polyurea modifier is obtained;

s3, reacting the polyurea modifier obtained in the step S2 with the carbon nanotube modified by the active group to obtain the modified carbon nanotube.

More preferably, the long chain alkyl diol in step S1 is selected from C12-C24 linear alkyl diols.

More preferably, the diamine in step S2 is selected from C2-C20 diamine or aromatic diamine.

More preferably, the molar ratio of isocyanate groups in the prepolymer to primary amino groups in the diamine in step S2 is 1:0.6-1.3.

More preferably, the reactive group in step S3 is an organic group that can react with a primary amino group or an isocyanate group at a temperature below 60 ℃.

More preferably, the weight ratio of the polyurea modifier to the active group modified carbon nanotube in the step S3 is 0.01-1:1.

Further preferably, the weight ratio of the polyurea modifier to the active group modified carbon nanotube in the step S3 is 0.1-1:1.

Preferably, the maleic anhydride grafted polyolefin is selected from one or more of MAH-g-PE, MAH-g-PP and MAH-g-POE.

Preferably, the raw material component further comprises: 0-2 parts of an anti-ultraviolet agent, 0-2 parts of an antioxidant, 0-50 parts of a filler, 0-1 part of an opening agent and 0-2 parts of a lubricant.

The carbon nano tube is jointly modified by adopting the long-chain alkyl structure and the polyurea structure, the long-chain alkyl structure can improve the compatibility of the carbon nano tube and the polypropylene, and the polyurea structure is subjected to microphase separation due to large polarity difference with the long-chain alkyl structure, so that the impact strength of the polypropylene is improved.

In the application, the modified polypropylene composition contains maleic anhydride grafted polyolefin, so that the impact resistance of polypropylene can be improved, or the dispersibility of filler in polypropylene can be improved, or the filler can react with active groups in the modified carbon nano tube to form a crosslinked structure, and then the crosslinked structure and the polypropylene form a semi-interpenetrating polymer network structure, so that the mechanical strength, impact resistance, heat resistance and the like of the modified polypropylene are further improved.

The application has at least the following beneficial effects: the modified carbon nano tube and the maleic anhydride grafted polyolefin are added into the modified polypropylene composition, so that the mechanical strength, impact resistance, heat resistance, antistatic property and other properties of the polypropylene are improved.

Detailed Description

The technical scheme of the application is further illustrated and described through the following specific embodiments.

The application provides a modified polypropylene composition, which comprises the following raw materials in parts by weight: 100 parts of polypropylene, 0.5-10 parts of modified carbon nano tube and 0-5 parts of maleic anhydride grafted polypropylene.

In the present application, polypropylene is not particularly limited, and may be atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene or the like, and the melt index (230 ℃ C., 2.16 Kg) of polypropylene may be 1 to 50g/10min.

The modified polypropylene composition of the application preferably has a maleic anhydride grafted polypropylene fraction of 0.3-5 parts.

In a preferred embodiment of the present application, the modified carbon nanotubes are prepared as follows:

In step S1, the diisocyanate is not particularly limited, and may be selected from isophorone diisocyanate (IPDI), toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene Diisocyanate (HDI), and the like, for example.

The long-chain alkyl glycol reacts with excessive diisocyanate to obtain isocyanate-terminated polyurethane prepolymer, the polyurethane prepolymer and diamine undergo chain extension reaction to obtain polyester/urea modifier containing urea bonds, urethane bonds and long-chain alkyl groups, the modifier is grafted to the surface of the carbon nanotube through grafting reaction, a grafted polymer chain segment on the surface of the carbon nanotube contains urea bonds, urethane bonds and long-chain alkyl groups, the carbon nanotube can improve the mechanical strength, antistatic performance and the like of polypropylene, the urea bonds and the urethane bonds can improve the shock resistance of polypropylene, and the long-chain alkyl groups can improve the dispersibility of the carbon nanotube in polypropylene and the compatibility of the carbon nanotube with polypropylene.

In a more preferred embodiment of the present application, the long chain alkyl diol in step S1 is selected from C12-C24 linear alkyl diols. In the application, the C12-C24 linear alkyl glycol refers to a molecular structure containing 12-24 carbon atoms, wherein the carbon atoms are of a linear structure, and two hydroxyl groups are positioned at two end groups of the molecule. The C12-C24 linear alkyl glycol is adopted, wherein the C12-C24 linear alkyl has better compatibility with polypropylene, and the compatibility of the modified carbon nano tube and the polypropylene can be improved. For example, the C12-C24 linear alkyl diol may be selected from the group consisting of 1, 12-dodecyl diol, 1, 14-tetradecyl diol, 1, 18-octadecyl diol, 1, 22-docosyl diol, and the like.

In a more preferred embodiment of the present application, the diamine in step S2 is selected from C2-C20 diamine or aromatic diamine. In the application, the C2-C20 diamine refers to a molecular structure containing 2-20 carbon atoms, wherein two amino groups can be positioned at two end groups of the molecule, 1 can be positioned at the end groups, the other 1 can be positioned at a lateral group, and the two amino groups can be positioned at the lateral group. Further preferably, the C2-C20 diamine is a C2-C20 linear diamine, with both amino groups located at both end groups of the molecule. By way of example, the C2-C20 diamine may be ethylenediamine, 1, 4-butanediamine, 1, 6-hexanediamine, 1, 8-octanediamine, 1, 12-dodecanediamine, 1, 16-hexadecylenediamine, 1, 18-octadecyldiamine, and the like.

The molecular structure of the aromatic diamine contains aromatic groups, such as phenyl, and the molecular structure also contains 2 amino groups, wherein the 2 amino groups can be directly connected with the aromatic groups or connected with saturated carbon atoms. By way of example, the aromatic diamine may be 1, 4-phenylenediamine, 1, 3-phenylenediamine, 4' -diaminodiphenyl ether, 3,4' -diaminodiphenyl ether, 4' -diaminodiphenyl methane, and the like.

In a more preferred embodiment of the application, the molar ratio of isocyanate groups in the prepolymer to primary amino groups in the diamine in step S2 is from 1:0.6 to 1.3. The resulting capping agents have different end groups depending on the molar ratio of isocyanate groups in the prepolymer to primary amino groups in the diamine. When the molar ratio of isocyanate groups in the prepolymer to primary amino groups in diamine is lower than 1, such as 1:1.1, 1:1.2, 1:1.3, etc., primary amino groups are excessive, and two end groups of the end capping agent are amino groups; when the molar ratio of isocyanate groups in the prepolymer to primary amino groups in the diamine is higher than 1, such as 1:0.6, 1:7, 1:0.8, etc., the isocyanate groups are excessive, and the two end groups of the blocking agent are isocyanate groups.

In a more preferred embodiment of the application, the reactive group in step S3 is an organic group which reacts with a primary amino group or an isocyanate group at a temperature below 60 ℃. For example, the reactive group may be an organic group that reacts with a primary amino group, such as an epoxy group, a carbon-carbon double bond; the reactive groups may also be organic groups with isocyanate groups, such as primary amino groups, secondary amino groups, hydroxyl groups, and the like.

In a more preferred embodiment of the present application, the weight ratio of the polyurea modifier to the reactive group modified carbon nanotubes in step S3 is 0.01-1:1. And grafting the polyurea modifier structure to the surface of the carbon nano tube through the reaction of the polyurea modifier and the active group. When the surface of the carbon nano tube contains active groups such as primary amino, secondary amino, hydroxyl and the like which can react with isocyanate, the polyurea modifier can be blocked by isocyanate; when the surface of the carbon nano tube contains epoxy groups, carbon-carbon double bonds and other active groups which can react with primary amino groups, the polyurea modifier can be blocked by the primary amino groups. The modified carbon nano tube can also contain organic groups which react with acid anhydride, such as primary amino, hydroxyl and the like, can be introduced by the polyurea modifier, can also be derived from active groups to modify the carbon nano tube, can form a cross-linked structure with maleic anhydride grafted polyolefin, and can form a semi-interpenetrating polymer network structure with polypropylene high molecular chains, so that the mechanical strength, the heat resistance and the like of the polypropylene are further improved. Further preferred, the weight ratio of polyurea modifier to active group modified carbon nanotubes is 0.1-1:1, for example, the weight ratio may be 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1, 0.8:1, 0.85:1, 0.9:1, 0.95:1, 1:1, etc.

In the present application, the carbon nanotubes may be single-walled carbon nanotubes SWCNT or multi-walled carbon nanotubes MWCNT. The carbon nanotubes modified with active groups may be prepared according to the prior art, for example, hydroxyl-modified carbon nanotubes, epoxy-modified carbon nanotubes may be obtained by oxidation of carbon nanotubes, or epoxy-modified carbon nanotubes may be obtained by reaction of hydroxyl-modified carbon nanotubes with KH-560 silane coupling agents. The amino-modified carbon nanotubes can be obtained by reacting an aminosilane coupling agent (such as 3-aminopropyl trimethoxysilane) with the oxidized carbon nanotubes.

In a preferred embodiment of the application, the maleic anhydride grafted polyolefin is selected from one or more of MAH-g-PE, MAH-g-PP and MAH-g-POE. In the present application, the grafting ratio of maleic anhydride in the maleic anhydride-grafted polyolefin is not particularly limited and may be 0.5 to 5%.

In a preferred embodiment of the present application, the raw material composition further comprises: 0-2 parts of an anti-ultraviolet agent, 0-2 parts of an antioxidant, 0-50 parts of a filler, 0-1 part of an opening agent and 0-2 parts of a lubricant. In the application, the filler can be inorganic filler such as talcum powder, wollastonite, silicon dioxide, titanium dioxide, glass beads and the like, and the anti-ultraviolet agent, the antioxidant, the opening agent and the lubricant are all additives commonly used for polypropylene and can be obtained from commercial products.

In the present application, the preparation method of the modified polypropylene composition is not particularly limited, and one preparation method is as follows: mixing the raw material components together, adding into a double-screw extruder, and performing melt extrusion molding at 180-220 ℃. The temperature of the first area is 120-130 ℃, the temperature of the second area is 160-170 ℃, the temperature of the third area is 180-190 ℃, the temperature of the fourth area is 190-200 ℃, the temperature of the fifth area is 210-220 ℃, the temperature of the sixth area is 200-210 ℃, the temperature of the seventh area is 190-200 ℃, the temperature of the eighth area is 180-190 ℃, the temperature of the ninth area is 180-190 ℃, the temperature of the die head is 180 ℃, the stirring rotating speed is 32rpm, and the length-diameter ratio is 35:1.

The technical scheme of the application is further described and illustrated below according to various embodiments. The parts are by weight in the examples below, unless otherwise indicated.

Preparation examples 1-4 preparation of modified carbon nanotubes

The epoxy group modified SWCNTs of preparation examples 1,2, 4 were prepared as follows: taking a certain amount of absolute ethyl alcohol, dripping a proper amount of diluted hydrochloric acid, regulating the pH value to be 4.5-5.5, and adding a certain amount of KH560 to prepare a mixed solution with the mass fraction of 2%. Stirring with a glass rod, reacting for 5min, and hydrolyzing. Adding the single-arm carbon nano tube which is oxidized by mixed acid and is 0.1 percent of the weight of the mixed solution, performing ultrasonic dispersion for 1h, heating to 60 ℃, stirring for 6h, taking out, cooling to room temperature, washing with acetone for 2 times, performing vacuum filtration, and performing vacuum drying at 80 ℃ to obtain the nano-tube.

The amino group-modified SWCNT of preparation example 3 was prepared as follows: taking a certain amount of absolute ethyl alcohol, adding a certain amount of KH540, and preparing a mixed solution with the mass fraction of 2%. Stirring with a glass rod, reacting for 5min, and hydrolyzing. Adding the single-arm carbon nano tube which is oxidized by mixed acid and is 0.1 percent of the weight of the mixed solution, performing ultrasonic dispersion for 1h, heating to 50 ℃, stirring for 6h, taking out, cooling to room temperature, washing with acetone for 2 times, performing vacuum filtration, and performing vacuum drying at 80 ℃ to obtain the nano-tube.

Preparation example 1

Adding 1, 12-dodecyl glycol and IPDI into a reaction vessel according to the molar ratio of 0.62:1, adding 1, 12-dodecyl glycol and 0.1% of dibutyltin dilaurate by weight of the IPDI, heating to 70+/-2 ℃, reacting for 3 hours, and cooling to obtain a prepolymer;

adding 1, 4-butanediamine into the prepolymer for chain extension according to the mol ratio of isocyanate groups in the prepolymer to primary amino groups in the 1, 4-butanediamine being 1:1.1, so as to obtain a polyurea modifier;

1 part of epoxy group modified SWCNT is dispersed into 200 parts of butyl acetate by ultrasonic, 0.4 part of polyurea modifier is added, stirring reaction is carried out for 6 hours, filtering is carried out, the filtered solid is washed by absolute ethyl alcohol for 2 times, and drying is carried out at 50 ℃ for overnight, thus obtaining the modified carbon nanotube.

Preparation example 2

Adding 1, 18-octadecyl glycol and IPDI into a reaction vessel according to the molar ratio of 0.8:1, adding 1, 18-octadecyl glycol and 0.1% of dibutyltin dilaurate by weight of the IPDI, heating to 70+/-2 ℃, reacting for 3 hours, and cooling to obtain a prepolymer;

adding 1, 12-dodecyl diamine into the prepolymer for chain extension according to the mol ratio of isocyanate groups in the prepolymer to primary amino groups in the 1, 12-dodecyl diamine of 1:1.15, so as to obtain a polyurea modifier;

1 part of epoxy group modified SWCNT is dispersed into 200 parts of butyl acetate by ultrasonic, 0.5 part of polyurea modifier is added, stirring reaction is carried out for 6 hours, filtration is carried out, the filtered solid is washed with absolute ethyl alcohol for 2 times, and drying is carried out at 50 ℃ for overnight, thus obtaining the modified carbon nanotube.

Preparation example 3

Adding 1, 18-octadecyl glycol and HMDI into a reaction vessel according to the molar ratio of 0.9:1, adding 1, 18-octadecyl glycol, HMDI weight and 0.1% dibutyltin dilaurate, heating to 70+/-2 ℃, reacting for 3 hours, and cooling to obtain a prepolymer;

adding 1, 8-octanediamine into the prepolymer for chain extension according to the mol ratio of isocyanate groups in the prepolymer to primary amino groups in the 1, 8-octanediamine being 1:0.9, so as to obtain a polyurea modifier;

1 part of amino group modified SWCNT is ultrasonically dispersed into 200 parts of butyl acetate, 0.25 part of polyurea modifier is added, stirring reaction is carried out for 6 hours, filtering is carried out, the filtered solid is washed with absolute ethyl alcohol for 2 times, and drying is carried out at 50 ℃ for overnight, thus obtaining the modified carbon nanotube.

Preparation example 4

Adding 1, 12-dodecyl glycol and HMDI into a reaction vessel according to the mol ratio of 0.95:1, adding 1, 12-dodecyl glycol, HMDI weight and 0.1% dibutyltin dilaurate, heating to 70+/-2 ℃, reacting for 3 hours, and cooling to obtain a prepolymer;

adding 1, 12-dodecyl diamine into the prepolymer for chain extension according to the mol ratio of isocyanate groups in the prepolymer to primary amino groups in the 1, 12-dodecyl diamine of 1:1.05, so as to obtain a polyurea modifier;

1 part of epoxy group modified SWCNT is dispersed into 200 parts of butyl acetate by ultrasonic, 0.7:1 part of polyurea modifier is added, stirring reaction is carried out for 6 hours, filtering is carried out, the filtered solid is washed with absolute ethyl alcohol for 2 times, and drying is carried out at 50 ℃ for overnight, thus obtaining the modified carbon nanotube.

The polypropylene in each of the following examples and comparative examples is the same isotactic polypropylene and has a melt index (230 ℃ C., 2.16 Kg) of 10g/10min, but is not represented as a limitation on the technical scheme of the present application.

Example 1

The raw materials comprise the following components: 100 parts of polypropylene, 1 part of modified carbon nanotube of preparation example 1 and 2 parts of maleic anhydride grafted polypropylene (the grafting ratio of maleic anhydride is 2.2%), the raw material components are mixed together, added into a double screw extruder, and melt extrusion molding is carried out at 180-220 ℃ to obtain a modified polypropylene composition. The temperature of the first area is 120-130 ℃, the temperature of the second area is 160-170 ℃, the temperature of the third area is 180-190 ℃, the temperature of the fourth area is 190-200 ℃, the temperature of the fifth area is 210-220 ℃, the temperature of the sixth area is 200-210 ℃, the temperature of the seventh area is 190-200 ℃, the temperature of the eighth area is 180-190 ℃, the temperature of the ninth area is 180-190 ℃, the temperature of the die head is 180 ℃, the stirring rotating speed is 32rpm, and the length-diameter ratio is 35:1.

Example 2

In example 1, the modified carbon nanotube of preparation example 1 was adjusted from 1 part to 4 parts, and the remaining steps were kept unchanged.

Example 3

In example 1, the modified carbon nanotube of preparation example 1 was adjusted from 1 part to 9 parts, and the remaining steps were kept unchanged.

Example 4

The raw materials comprise the following components: 100 parts of polypropylene, 5 parts of modified carbon nano tubes of preparation example 2, 1 part of oleamide and 0.8 part of antioxidant 1010.

A modified polypropylene composition was prepared according to the preparation method of example 1.

Example 5

The starting components in example 4 were increased by 0.5 part of maleic anhydride-grafted polypropylene (maleic anhydride grafting ratio 0.8%) and the rest of the procedure was kept unchanged.

Example 6

In example 5, the fraction of maleic anhydride-grafted polypropylene was adjusted from 0.5 parts to 2.5 parts, the remainder of the procedure remaining unchanged.

Example 7

In example 5, the fraction of maleic anhydride-grafted polypropylene was adjusted from 0.5 parts to 5 parts, the remaining steps remaining unchanged.

Example 8

The raw materials comprise the following components: 100 parts of polypropylene, 6 parts of modified carbon nanotubes of preparation example 3, 1.5 parts of maleic anhydride-grafted polypropylene (maleic anhydride grafting ratio 1.2%), 40 parts of talcum powder with an average particle size of 1.5 mu m and 0.6 part of antioxidant 1010.

Example 9

The raw materials comprise the following components: 100 parts of polypropylene, 3 parts of modified carbon nanotubes of preparation example 4, 1.5 parts of maleic anhydride-grafted polypropylene of example 8, 50 parts of talcum powder with an average particle size of 1.5 mu m and 0.6 part of antioxidant 1010.

Comparative example 1

Taking a certain amount of absolute ethyl alcohol, dripping a proper amount of diluted hydrochloric acid, regulating the pH value to be 4.5-5.5, and adding a certain amount of n-dodecyl trimethoxy silane to prepare a mixed solution with the mass fraction of 2%. Stirring with a glass rod, reacting for 5min, and hydrolyzing. Adding the single-arm carbon nano tube which is oxidized by mixed acid and is 0.1 percent of the weight of the mixed solution, performing ultrasonic dispersion for 1h, heating to 60 ℃, stirring for 6h, taking out, cooling to room temperature, washing with acetone for 2 times, performing vacuum filtration, and performing vacuum drying at 80 ℃ to obtain the long-chain alkyl modified SWCNT.

In example 2, the modified carbon nanotubes of preparation example 1 were replaced with the long chain alkyl modified SWCNT described above in equal parts by weight, with the remaining steps remaining unchanged.

Comparative example 2

The 1, 12-dodecyl glycol of preparation 1 was replaced with equimolar 1, 4-butanediol, and the rest of the procedure was kept unchanged, obtaining short chain alkyl modified SWCNT.

In example 2, the modified carbon nanotubes of preparation example 1 were replaced with an equal weight fraction of the above short chain alkyl modified SWCNTs, the rest of the procedure being unchanged.

Flexural strength: tested according to the method of GB/T9341-2008.

Tensile strength: tested according to the method of GB/T1040-2006.

Notched impact strength: tested according to the method of GB/T1843-2008.

Heat distortion temperature: tested according to the method of GB/T1633-2000, the pressure is 0.45MPa.

The results are shown in Table 1 below.

TABLE 1 Performance test results

As is evident from the data in Table 1 above, the modified polypropylene composition of the present application is significantly better in mechanical strength, impact strength and heat resistance. Comparative example 2, comparative example 1 and comparative example 2, the modified polypropylene composition of the application has better mechanical strength, impact strength and heat resistance. Comparative examples 1 to 3, the modified polypropylene composition was better in mechanical strength, impact strength and heat resistance with increasing content of the modified carbon nanotubes in the modified polypropylene composition. Comparative examples 4 to 7, as the content of the maleic anhydride-grafted polyolefin in the modified polypropylene composition increases, the mechanical strength, impact strength and heat resistance are also improved.

As described above, the basic principles, main features and advantages of the present application are shown and described. It will be appreciated by persons skilled in the art that the present application is not limited to the embodiments described above, which are preferred embodiments of the present application, and the scope of the application is not limited thereto, i.e. equivalent changes and modifications as defined by the claims and the description herein should be made while remaining within the scope of the application. The scope of the application is defined by the appended claims and equivalents thereof.

Claims

1. The modified polypropylene composition is characterized by comprising the following raw material components in parts by weight: 100 parts of polypropylene, 0.5 to 10 parts of modified carbon nano-tubes and 0 to 5 parts of maleic anhydride grafted polyolefin.

2. The modified polypropylene composition according to claim 1, wherein the modified carbon nanotubes are prepared by the steps of:

3. The modified polypropylene composition according to claim 2, wherein the long chain alkyl glycol in step S1 is selected from the group consisting of C12-C24 linear alkyl glycols.

4. The modified polypropylene composition according to claim 2, wherein the diamine in step S2 is selected from C2-C20 diamine or aromatic diamine.

5. The modified polypropylene composition according to claim 2, wherein the molar ratio of isocyanate groups in the prepolymer to primary amino groups in the diamine in step S2 is 1:0.6-1.3.

6. The modified polypropylene composition according to claim 2, wherein the reactive group in step S3 means an organic group which can react with a primary amino group or an isocyanate group at 60 ℃ or less.

7. The modified polypropylene composition according to claim 2, wherein the weight ratio of the polyurea modifier to the reactive group modified carbon nanotubes in step S3 is 0.01-1:1.

8. The modified polypropylene composition according to claim 7, wherein the weight ratio of the polyurea modifier to the reactive group modified carbon nanotubes in step S3 is 0.1 to 1:1.

9. The modified polypropylene composition according to claim 1, wherein the maleic anhydride grafted polyolefin is selected from one or more of MAH-g-PE, MAH-g-PP and MAH-g-POE.

10. The modified polypropylene composition according to claim 1, wherein the raw material component further comprises: 0-2 parts of an anti-ultraviolet agent, 0-2 parts of an antioxidant, 0-50 parts of a filler, 0-1 part of an opening agent and 0-2 parts of a lubricant.