A weather-resistant PP composite material and preparation method thereof

Abstract

The invention discloses a weather-resistant PP composite material and a preparation method thereof, and relates to the technical field of PP material preparation. The PP composite material comprises the following steps: 80-100 parts of PP masterbatch, 10-15 parts of modified filler, 1-1.5 parts of titanium dioxide, 0.5-0.8 parts of dicumyl peroxide and 2-5 parts of dibutyl phthalate, wherein in the raw material base process, the maleimide structure on the surface of the modified filler is grafted with the PP molecular chain, and an organic silicon segment containing a benzotriazole structure is inserted into the molecular chain, and when irradiated with ultraviolet light, the hydrogen bond in the intramolecular hydrogen bond chelate ring formed by the hydroxyl group and the nitrogen on the triazole group is broken or a phototautomer is formed, and harmful ultraviolet light energy is converted into harmless heat energy and released, and the addition of graphene can shield part of the light from directly acting on the molecular chain, and the mechanical properties of the material are increased by acting with the imide bond, so that the material will not be obviously brittle when used outdoors for a long time.

Description

Technical Field

[0001] The invention relates to the technical field of PP material preparation, and in particular to a weather-resistant PP composite material and a preparation method thereof. Background Art

[0002] Polypropylene is one of the five most common plastics in the world today. It is an important member of polymer materials and the first synthetic isotactic polymer to achieve industrial mass production. Polypropylene resin has abundant raw materials, low production cost, and light weight. It is a thermoplastic resin that is easy to mold and process and has excellent physical and mechanical properties. It has a wide range of applications, covering thermoplastics, fibers, films and other fields. Soon after isotactic polypropylene was industrialized, polypropylene was industrialized. However, the obvious disadvantage of polypropylene is that it has poor weather resistance. Long-term outdoor use will cause discoloration and brittleness, which affects the normal use of the material. Summary of the invention

[0003] The purpose of the present invention is to provide a weather-resistant PP composite material and a preparation method thereof, so as to solve the problem that the weather resistance of PP plastics at present is poor.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A method for preparing a weather-resistant PP composite material comprises the following steps:

[0006] Step A1: dispersing graphene oxide in DMF, stirring and adding a modifier and dicyclohexylcarbodiimide at a speed of 200-300 r / min and a temperature of 80-90° C., reacting for 8-10 hours to obtain pretreated graphene, and uniformly mixing the pretreated graphene, maleic anhydride, triethylamine and toluene, and reflux reacting for 2-3 hours at a speed of 60-80 r / min and a temperature of 115-120° C. to obtain a modified filler;

[0007] Step A2: Weigh the following raw materials in parts by weight: 80-100 parts of PP masterbatch, 10-15 parts of modified filler, 1-1.5 parts of titanium dioxide, 0.5-0.8 parts of diisopropylbenzene peroxide and 2-5 parts of dibutyl phthalate, mix the raw materials and add them into an extruder, and extrude and granulate under the conditions of zone 1 temperature of 160-165°C, zone 2 temperature of 165-175°C, zone 3 temperature of 175-185°C, zone 4 temperature of 185-195°C, and die head temperature of 180-185°C to obtain a weather-resistant PP composite material.

[0008] Furthermore, the mass ratio of graphene oxide and modifier described in step A1 is 1:15, the amount of dicyclohexylcarbodiimide is 5% of the mass of the modifier, and the pretreated graphene, maleic anhydride, triethylamine and toluene are 1 g:50 mmol:120 mmol:30 mL.

[0009] Further, the modifier is prepared by the following steps:

[0010] Step B1: Concentrated hydrochloric acid and deionized water are mixed, and 3-nitro-4-aminophenol is added under stirring at a speed of 600-800 r / min and a temperature of 20-25° C. to react for 30-40 min, and then the temperature is lowered to 0-5° C., sodium nitrite is added, and the reaction is carried out for 30-40 min to obtain a diazonium salt, and m-aminophenol, sodium carbonate and deionized water are mixed uniformly, and the diazonium salt is added under stirring at a speed of 600-800 r / min and a temperature of 0-5° C. to react for 2-3 h to obtain an azo compound;

[0011] The reaction process is as follows:

[0012]

[0013] Step B2: uniformly mix the azo compound, sodium hydroxide and deionized water, add thiourea dioxide at a speed of 60-80 r / min and a temperature of 70-75° C., raise the temperature to 80-85° C., react for 3-4 hours, add glacial acetic acid, filter and remove the filtrate to obtain intermediate 1, uniformly mix intermediate 1, terephthalaldehyde and ethanol, and reflux for reaction at a speed of 120-150 r / min and a temperature of 80-85° C. for 3-5 hours to obtain intermediate 2;

[0014] The reaction process is as follows:

[0015]

[0016] Step B3: Mix the intermediate 2, methyl-(3-isocyanatopropyl)dimethylsilane and DMF, introduce nitrogen protection, stir and add dibutyltin dilaurate at a speed of 150-200 r / min and a temperature of 40-50°C, and react for 3-5 hours to obtain a modified monomer. Mix the modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane, a strongly acidic cation exchange resin and deionized water, introduce nitrogen protection, and react for 2-3 hours at a speed of 120-150 r / min and a temperature of 90-100°C to obtain a modifier.

[0017] The reaction process is as follows:

[0018]

[0019]

[0020] Furthermore, the ratio of concentrated hydrochloric acid, deionized water, 3-nitro-4-aminophenol and sodium nitrite described in step B1 is 14 mL: 8 mL: 5 g: 2.8 g, and the ratio of m-aminophenol, sodium carbonate, deionized water and diazonium salt is 60 mmol: 4.2 g: 150 mL: 60 mmol.

[0021] Furthermore, the amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step B2 is 5g:9.6g:75mL:1g:25mL, and the molar ratio of intermediate 1 to terephthalaldehyde is 2:1.

[0022] Furthermore, the molar ratio of the intermediate 2 and methyl-(3-isocyanatepropyl)dimethylsilane described in step B3 is 1:2, the amount of dibutyltin dilaurate is 1% of the mass of methyl-(3-isocyanatepropyl)dimethylsilane, the amount ratio of the modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane and deionized water is 0.1 mol:4 mol:2.8 mol:5 L, and the amount of the strongly acidic cation exchange resin is 7% of the mass of octamethylcyclotetrasiloxane.

[0023] Beneficial effects of the present invention: A weather-resistant PP composite material prepared by the present invention comprises the following raw materials: PP masterbatch, modified filler, titanium dioxide and dibutyl phthalate; the modified filler takes graphene oxide and a modifier as raw materials, and under the action of dicyclohexylcarbodiimide, the amino group on the modifier and the carboxyl group on the graphene oxide are dehydrated to obtain pretreated graphene; the pretreated graphene is reacted with maleic anhydride to form a maleimide structure on the surface to obtain the modified filler.

[0024] The modifier uses 3-nitro-4-aminophenol as a raw material and is treated with sodium nitrite to form a diazonium salt. The diazonium salt is reacted with m-aminophenol to obtain an azo compound. The azo compound is reduced to form a benzotriazole structure to obtain an intermediate 1. The intermediate 1 is reacted with terephthalaldehyde so that the amino group on the intermediate 1 reacts with the aldehyde group on the terephthalaldehyde to obtain an intermediate 2. The intermediate 2 is reacted with methyl-(3-isocyanatopropyl)dimethylsilane so that the hydroxyl group on the intermediate 2 away from the benzotriazole ring reacts with the isocyanate group on the methyl-(3-isocyanatopropyl)dimethylsilane to obtain a modified monomer. The siloxane on the modified monomer is hydrolyzed and catalyzed by ring-opening grafting with octamethylcyclotetrasiloxane under acidic conditions. Finally, it is terminated with 1,3-bis(aminopropyl)tetramethyldisiloxane to form an amino-terminated polysiloxane to obtain a modifier.

[0025] In the raw material-based process, the maleimide structure on the surface of the modified filler will be grafted with the PP molecular chain, thereby increasing the cross-linking sites. At the same time, a silicone segment containing a benzotriazole structure is inserted into the molecular chain. When exposed to ultraviolet light, the hydrogen bonds in the intramolecular hydrogen bond chelate ring formed by the hydroxyl group and the nitrogen on the triazole group are broken or phototautomers are formed, converting harmful ultraviolet light energy into harmless heat energy and releasing it, thereby preventing the molecular chain from being oxidized by ultraviolet light. The addition of graphene can shield part of the light from directly acting on the molecular chain, and the action with the imine bond increases the mechanical properties of the material, so that the material will not become obviously brittle when used outdoors for a long time. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Embodiment 1: A method for preparing a weather-resistant PP composite material, comprising the following steps:

[0028] Step A1: dispersing graphene oxide in DMF, stirring and adding a modifier and dicyclohexylcarbodiimide at a speed of 200 r / min and a temperature of 80° C., and reacting for 8 hours to obtain pretreated graphene, and uniformly mixing the pretreated graphene, maleic anhydride, triethylamine and toluene, and refluxing for 2 hours at a speed of 60 r / min and a temperature of 115° C. to obtain a modified filler;

[0029] Step A2: Weigh the following raw materials in parts by weight: 80 parts of PP masterbatch, 10 parts of modified filler, 1 part of titanium dioxide, 0.5 parts of diisopropylbenzene peroxide and 2 parts of dibutyl phthalate, mix the raw materials and add them into an extruder, and extrude and granulate under the conditions of a zone temperature of 160°C, a zone temperature of 165°C, a zone temperature of 175°C, a zone temperature of 185°C, and a die temperature of 180°C to obtain a weather-resistant PP composite material.

[0030] The mass ratio of graphene oxide and modifier described in step A1 is 1:15, the amount of dicyclohexylcarbodiimide is 5% of the mass of the modifier, and the pretreated graphene, maleic anhydride, triethylamine and toluene are 1g:50mmol:120mmol:30mL.

[0031] The PP masterbatch model described in step A2 is HP501M.

[0032] The modifier is prepared by the following steps:

[0033] Step B1: Concentrated hydrochloric acid and deionized water are mixed, and 3-nitro-4-aminophenol is added under stirring at a speed of 600 r / min and a temperature of 20° C. to react for 30 minutes, and then the temperature is lowered to 0° C., sodium nitrite is added, and the reaction is carried out for 30 minutes to obtain a diazonium salt, and m-aminophenol, sodium carbonate and deionized water are mixed uniformly, and the diazonium salt is added under stirring at a speed of 600 r / min and a temperature of 0° C. to react for 2 hours to obtain an azo compound;

[0034] Step B2: uniformly mix the azo compound, sodium hydroxide and deionized water, add thiourea dioxide at a speed of 60 r / min and a temperature of 70°C, raise the temperature to 80°C, react for 3 hours, add glacial acetic acid, filter and remove the filtrate to obtain intermediate 1, uniformly mix intermediate 1, terephthalaldehyde and ethanol, reflux for reaction at a speed of 120 r / min and a temperature of 80°C for 3 hours to obtain intermediate 2;

[0035] Step B3: Intermediate 2, methyl-(3-isocyanatopropyl)dimethylsilane and DMF were mixed, nitrogen was introduced for protection, dibutyltin dilaurate was added under stirring at a speed of 150 r / min and a temperature of 40°C, and the reaction was carried out for 3 hours to obtain a modified monomer, and the modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane, strongly acidic cation exchange resin and deionized water were mixed, nitrogen was introduced for protection, and the reaction was carried out at a speed of 120 r / min and a temperature of 90°C for 2 hours to obtain a modifier.

[0036] The concentrated hydrochloric acid, deionized water, 3-nitro-4-aminophenol and sodium nitrite described in step B1 are 14mL:8mL:5g:2.8g, and the amount ratio of m-aminophenol, sodium carbonate, deionized water and diazonium salt is 60mmol:4.2g:150mL:60mmol.

[0037] The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step B2 is 5g:9.6g:75mL:1g:25mL, and the molar ratio of intermediate 1 to terephthalaldehyde is 2:1.

[0038] The molar ratio of intermediate 2 and methyl-(3-isocyanatepropyl)dimethylsilane described in step B3 is 1:2, the amount of dibutyltin dilaurate is 1% of the mass of methyl-(3-isocyanatepropyl)dimethylsilane, the amount ratio of modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane and deionized water is 0.1mol:4mol:2.8mol:5L, and the amount of strongly acidic cation exchange resin is 7% of the mass of octamethylcyclotetrasiloxane.

[0039] Embodiment 2: A method for preparing a weather-resistant PP composite material, comprising the following steps:

[0040] Step A1: dispersing graphene oxide in DMF, stirring and adding a modifier and dicyclohexylcarbodiimide at a speed of 200 r / min and a temperature of 85° C., and reacting for 9 hours to obtain pretreated graphene, and uniformly mixing the pretreated graphene, maleic anhydride, triethylamine and toluene, and refluxing for 3 hours at a speed of 60 r / min and a temperature of 115° C. to obtain a modified filler;

[0041] Step A2: Weigh the following raw materials in parts by weight: 90 parts of PP masterbatch, 13 parts of modified filler, 1.3 parts of titanium dioxide, 0.6 parts of diisopropylbenzene peroxide and 3 parts of dibutyl phthalate, mix the raw materials and add them into an extruder, and extrude and granulate under the conditions of a zone 1 temperature of 160°C, a zone 2 temperature of 175°C, a zone 3 temperature of 185°C, a zone 4 temperature of 195°C, and a die head temperature of 180°C to obtain a weather-resistant PP composite material.

[0042] The mass ratio of graphene oxide and modifier described in step A1 is 1:15, the amount of dicyclohexylcarbodiimide is 5% of the mass of the modifier, and the pretreated graphene, maleic anhydride, triethylamine and toluene are 1g:50mmol:120mmol:30mL.

[0043] The PP masterbatch model described in step A2 is HP501M.

[0044] The modifier is prepared by the following steps:

[0045] Step B1: Concentrated hydrochloric acid and deionized water are mixed, and 3-nitro-4-aminophenol is added under stirring at a speed of 600 r / min and a temperature of 25° C. to react for 35 minutes, and then the temperature is lowered to 3° C., sodium nitrite is added, and the reaction is carried out for 35 minutes to obtain a diazonium salt, and m-aminophenol, sodium carbonate and deionized water are mixed uniformly, and the diazonium salt is added under stirring at a speed of 600 r / min and a temperature of 3° C. to react for 2.5 hours to obtain an azo compound;

[0046] Step B2: uniformly mix the azo compound, sodium hydroxide and deionized water, add thiourea dioxide at a speed of 80 r / min and a temperature of 70°C, raise the temperature to 80°C, react for 4 hours, add glacial acetic acid, filter and remove the filtrate to obtain intermediate 1, uniformly mix intermediate 1, terephthalaldehyde and ethanol, reflux for 4 hours at a speed of 120 r / min and a temperature of 85°C to obtain intermediate 2;

[0047] Step B3: Intermediate 2, methyl-(3-isocyanatopropyl)dimethylsilane and DMF were mixed, nitrogen was introduced for protection, and dibutyltin dilaurate was added under stirring at a speed of 150 r / min and a temperature of 45°C, and the reaction was carried out for 4 hours to obtain a modified monomer. The modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane, a strongly acidic cation exchange resin and deionized water were mixed, nitrogen was introduced for protection, and the reaction was carried out at a speed of 120 r / min and a temperature of 95°C for 3 hours to obtain a modifier.

[0048] The concentrated hydrochloric acid, deionized water, 3-nitro-4-aminophenol and sodium nitrite described in step B1 are 14mL:8mL:5g:2.8g, and the amount ratio of m-aminophenol, sodium carbonate, deionized water and diazonium salt is 60mmol:4.2g:150mL:60mmol.

[0049] The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step B2 is 5g:9.6g:75mL:1g:25mL, and the molar ratio of intermediate 1 to terephthalaldehyde is 2:1.

[0050] The molar ratio of intermediate 2 and methyl-(3-isocyanatepropyl)dimethylsilane described in step B3 is 1:2, the amount of dibutyltin dilaurate is 1% of the mass of methyl-(3-isocyanatepropyl)dimethylsilane, the amount ratio of modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane and deionized water is 0.1mol:4mol:2.8mol:5L, and the amount of strongly acidic cation exchange resin is 7% of the mass of octamethylcyclotetrasiloxane.

[0051] Embodiment 3: A method for preparing a weather-resistant PP composite material, comprising the following steps:

[0052] Step A1: dispersing graphene oxide in DMF, stirring and adding a modifier and dicyclohexylcarbodiimide at a speed of 300 r / min and a temperature of 90° C., and reacting for 10 hours to obtain pretreated graphene, and uniformly mixing the pretreated graphene, maleic anhydride, triethylamine and toluene, and refluxing for 3 hours at a speed of 80 r / min and a temperature of 120° C. to obtain a modified filler;

[0053] Step A2: Weigh the following raw materials in parts by weight: 100 parts of PP masterbatch, 15 parts of modified filler, 1.5 parts of titanium dioxide, 0.8 parts of diisopropylbenzene peroxide and 5 parts of dibutyl phthalate, mix the raw materials and add them into an extruder, and extrude and granulate under the conditions of a zone 1 temperature of 165°C, a zone 2 temperature of 175°C, a zone 3 temperature of 185°C, a zone 4 temperature of 195°C, and a die head temperature of 185°C to obtain a weather-resistant PP composite material.

[0054] The mass ratio of graphene oxide and modifier described in step A1 is 1:15, the amount of dicyclohexylcarbodiimide is 5% of the mass of the modifier, and the pretreated graphene, maleic anhydride, triethylamine and toluene are 1g:50mmol:120mmol:30mL.

[0055] The PP masterbatch model described in step A2 is HP501M.

[0056] The modifier is prepared by the following steps:

[0057] Step B1: Concentrated hydrochloric acid and deionized water are mixed, stirred at a speed of 800 r / min and a temperature of 25° C., 3-nitro-4-aminophenol is added, and the reaction is carried out for 40 minutes, then the temperature is lowered to 5° C., sodium nitrite is added, and the reaction is carried out for 40 minutes to obtain a diazonium salt, and m-aminophenol, sodium carbonate and deionized water are mixed uniformly, stirred at a speed of 800 r / min and a temperature of 5° C., diazonium salt is added, and the reaction is carried out for 3 hours to obtain an azo compound;

[0058] Step B2: uniformly mix the azo compound, sodium hydroxide and deionized water, add thiourea dioxide at a speed of 80 r / min and a temperature of 75°C, raise the temperature to 85°C, react for 4 hours, add glacial acetic acid, filter and remove the filtrate to obtain intermediate 1, uniformly mix intermediate 1, terephthalaldehyde and ethanol, reflux for reaction at a speed of 150 r / min and a temperature of 85°C for 5 hours to obtain intermediate 2;

[0059] Step B3: Intermediate 2, methyl-(3-isocyanatopropyl)dimethylsilane and DMF were mixed, nitrogen was introduced for protection, dibutyltin dilaurate was added under stirring at a speed of 200 r / min and a temperature of 50°C, and the reaction was carried out for 5 hours to obtain a modified monomer, and the modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane, strongly acidic cation exchange resin and deionized water were mixed, nitrogen was introduced for protection, and the reaction was carried out at a speed of 150 r / min and a temperature of 100°C for 3 hours to obtain a modifier.

[0060] The concentrated hydrochloric acid, deionized water, 3-nitro-4-aminophenol and sodium nitrite described in step B1 are 14mL:8mL:5g:2.8g, and the amount ratio of m-aminophenol, sodium carbonate, deionized water and diazonium salt is 60mmol:4.2g:150mL:60mmol.

[0061] The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step B2 is 5g:9.6g:75mL:1g:25mL, and the molar ratio of intermediate 1 to terephthalaldehyde is 2:1.

[0062] The molar ratio of intermediate 2 and methyl-(3-isocyanatepropyl)dimethylsilane described in step B3 is 1:2, the amount of dibutyltin dilaurate is 1% of the mass of methyl-(3-isocyanatepropyl)dimethylsilane, the amount ratio of modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane and deionized water is 0.1mol:4mol:2.8mol:5L, and the amount of strongly acidic cation exchange resin is 7% of the mass of octamethylcyclotetrasiloxane.

[0063] Comparative Example 1: Compared with Example 1, graphene oxide was not added in this comparative example, and the remaining steps were the same.

[0064] Comparative Example 2: Compared with Example 1, this comparative example uses pretreated graphene instead of modified filler, and the remaining steps are the same.

[0065] Comparative Example 3: Compared with Example 1, this comparative example uses intermediate 1 instead of pre-treated graphene, and the remaining steps are the same.

[0066] The PP composite materials obtained in Examples 1-3 and Comparative Examples 1-3 were made into 168 mm × 13 mm × 3.2 mm specimens according to the standard of GB / T1040.3-2006, and the tensile speed was 50 mm / min. The initial tensile strength was tested. According to the standard of GB / T16422.3-2022, the irradiation intensity was 600 W / m 2 The cumulative irradiation is 400kWh / m 2 , the tensile strength decrease rate after light aging was detected, and the test results are shown in Table 1 below.

[0067] Table 1

[0068] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial tensile strength MPa 46.7 48.1 48.9 41.5 37.2 34.2 Tensile strength decrease rate after light aging % 2.72 2.24 1.83 4.36 3.18 3.54

[0069] It can be seen from Table 1 above that the present invention has good weather resistance.

[0070] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a weather-resistant PP composite material, characterized in that: The specific steps include: Step A1: dispersing graphene oxide in DMF, stirring and adding a modifier and dicyclohexylcarbodiimide, reacting for 8-10 hours to obtain pretreated graphene, and uniformly mixing the pretreated graphene, maleic anhydride, triethylamine and toluene, and reflux reaction to obtain a modified filler; Step A2: Weigh the following raw materials in parts by weight: 80-100 parts of PP masterbatch, 10-15 parts of modified filler, 1-1.5 parts of titanium dioxide, 0.5-0.8 parts of diisopropylbenzene peroxide and 2-5 parts of dibutyl phthalate, mix the raw materials and add them into an extruder, and extrude and granulate under the conditions of a zone 1 temperature of 160-165° C., a zone 2 temperature of 165-175° C., a zone 3 temperature of 175-185° C., a zone 4 temperature of 185-195° C., and a die head temperature of 180-185° C. to obtain a weather-resistant PP composite material; The modifier is prepared by the following steps: Step B1: Mixing concentrated hydrochloric acid and deionized water, stirring, adding 3-nitro-4-aminophenol, reacting, cooling, adding sodium nitrite, reacting, and obtaining a diazonium salt; mixing m-aminophenol, sodium carbonate, and deionized water, stirring, adding a diazonium salt, and reacting, and obtaining an azo compound; Step B2: uniformly mix an azo compound, sodium hydroxide and deionized water, stir and add thiourea dioxide to react, add glacial acetic acid, filter and remove the filtrate to obtain intermediate 1, and reflux the intermediate 1, terephthalaldehyde and ethanol to obtain intermediate 2; Step B3: Intermediate 2, methyl-(3-isocyanatopropyl)dimethylsilane and DMF are mixed, nitrogen is introduced for protection, and dibutyltin dilaurate is added for stirring to react to obtain a modified monomer. The modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane, a strongly acidic cation exchange resin and deionized water are mixed, nitrogen is introduced for protection, and a reaction is carried out to obtain a modifier.

2. The method for preparing a weather-resistant PP composite material according to claim 1, characterized in that: The mass ratio of graphene oxide and modifier described in step A1 is 1:15, and the amount ratio of pretreated graphene, maleic anhydride, triethylamine and toluene is 1g:50mmol:120mmol:30mL.

3. The method for preparing a weather-resistant PP composite material according to claim 1, characterized in that: The amount ratio of concentrated hydrochloric acid, deionized water, 3-nitro-4-aminophenol and sodium nitrite in step B1 is 14mL:8mL:5g:2.8g, and the amount ratio of m-aminophenol, sodium carbonate, deionized water and diazonium salt is 60mmol:4.2g:150mL:60mmol.

4. The method for preparing a weather-resistant PP composite material according to claim 1, characterized in that: The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step B2 is 5g:9.6g:75mL:1g:25mL, and the molar ratio of intermediate 1 to terephthalaldehyde is 2:

1.

5. The method for preparing a weather-resistant PP composite material according to claim 1, characterized in that: The molar ratio of intermediate 2 and methyl-(3-isocyanatopropyl)dimethylsilane in step B3 is 1:2, and the amount ratio of modified monomer, octamethylcyclotetrasiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane and deionized water is 0.1 mol:4 mol:2.8 mol:5 L.

6. A weather-resistant PP composite material, characterized in that: Prepared according to any one of the preparation methods described in claims 1-5.

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