High-barrier polypropylene material, preparation method thereof and application of high-barrier polypropylene material in organic silica gel sealing packaging material

Abstract

The invention discloses a high-barrier polypropylene material, a preparation method thereof and application of the high-barrier polypropylene material in an organic silica gel sealing packaging material, and relates to the technical field of high polymer materials. When the high-barrier polypropylene material is prepared, firstly, polypropylene is grafted with dichloro (vinyl) phosphine and vinylmethylsilane and then reacts with 1-ethylene-1H-pyrrole to obtain modified polypropylene, secondly, pretreated montmorillonite is subjected to demethylation through aluminum chloride and then reacts with 2-chloro-5-(1H-pyrrole-1-yl) pyridine to obtain the high-barrier polypropylene material. Then carrying out a reaction with N-triethyl-(4-vinylbenzyl) ammonium to obtain modified montmorillonite; and finally, mixing the modified polypropylene and the modified montmorillonite to obtain the high-barrier polypropylene material. The high-barrier polypropylene material prepared by the invention has high barrier rate, flame retardant property and ultraviolet aging resistance.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a high-barrier polypropylene material and a preparation method thereof and application thereof in organic silica gel sealing packaging materials. Background Art

[0002] Silicone rubber is a polymer compound widely used in the automotive, electronics, medical and other industries. It has excellent thermal stability, wear resistance and aging resistance, as well as good electrical insulation and waterproof properties. Its outer packaging material must have corresponding barrier properties, chemical resistance and toughness to ensure the stability and safety of silicone rubber during long-term storage and use.

[0003] Polypropylene is often used as a sealing material for silicone rubber because of its high melting point, bending strength, corrosion resistance, low density, low water absorption, and easy processing and molding. In order to meet the requirements of high barrier performance, polypropylene materials must have excellent gas barrier, moisture barrier, oil barrier, etc. to prevent the external environment from corroding silicone rubber. At the same time, in order to improve safety, polypropylene must also have flame retardant properties to slow down the spread of fire in the event of a fire. In addition, anti-ultraviolet aging performance is also an important characteristic required by polypropylene as a sealing material for silicone rubber to prevent material aging caused by ultraviolet radiation. Summary of the invention

[0004] The object of the present invention is to provide a high barrier polypropylene material and a preparation method thereof and application of the high barrier polypropylene material in organic silica gel sealing packaging materials, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a high barrier polypropylene material, comprising the following preparation steps: (1) Under anhydrous and oxygen-free conditions, polypropylene, toluene, dichloro(vinyl)phosphine, benzoyl peroxide, and vinylmethylsilane are mixed in a mass ratio of 1: (50-60): (0.2-0.3): (0.01-0.02): (0.2-0.3), and the mixture is heated to 60-70°C for reaction for 6-8 hours. After the reaction is completed, pre-modified polypropylene is obtained by vacuum rotary evaporation; (2) Under anhydrous and oxygen-free conditions, pre-modified polypropylene, toluene, aluminum chloride, and 1-ethylene-1H-pyrrole are mixed in a mass ratio of 1: (50-60): (0.03-0.05): (0.6-0.8), heated to 80°C and reacted for 4-6 hours. After the reaction, ethanol 3-4 times the volume of toluene is added, filtered, and dried under vacuum for 12 hours to obtain modified polypropylene; (3) Pretreated montmorillonite, aluminum chloride and toluene are mixed in a mass ratio of 1: (0.7-0.9): (50-60) and heated to 70-80°C for reaction for 5-6 hours. After the reaction, the mixture is filtered and washed with pure water for 3-4 times, and dried at room temperature for 12 hours to obtain pre-modified montmorillonite; (4) Pre-modified montmorillonite, 2-chloro-5-(1H-pyrrol-1-yl)pyridine, aluminum chloride and toluene are mixed in a mass ratio of 1: (0.7-0.9): (0.1-0.2): (50-60), heated to 60-70°C and stirred for 5-6 minutes, then heated to 95-100°C for reaction for 3-4 hours, filtered after the reaction and washed with pure water 3-4 times to obtain pyridine pyrrolyl montmorillonite; pyridine pyrrolyl montmorillonite and pure water are mixed in a mass ratio of 1:30, 0.2-0.3 times the mass of pyridine pyrrolyl montmorillonite is added with N-triethyl-(4-vinylbenzyl)ammonium chloride, stirred for 10 minutes, heated to 90°C and continued to react for 4 hours, filtered after the reaction and washed with pure water 3-4 times to obtain modified montmorillonite; (5) Modified polypropylene, modified montmorillonite, xylene and chloroplatinic acid are mixed in a mass ratio of 1: (0.03-0.05): (50-60): 0.003 for 20-30 minutes, poured into a glass mold, placed at 65°C for 48 hours, and then dried in an oven at 180°C for 20-30 minutes to obtain a high barrier polypropylene material.

[0006] As an optimization, the preparation method of the dichloro(vinyl)phosphine in step (1) is as follows: bis((N,N-diethyl)amino)chlorophosphine and tetrahydrofuran are mixed in a mass ratio of 21.07:250, cooled to -78°C, added with a vinylmagnesium bromide solution, heated to room temperature and stirred for 12 hours, concentrated under vacuum, then added with pentane in an amount 0.6 times the volume of tetrahydrofuran, filtered and retained the filtrate, then concentrated under vacuum, fractionated and purified to obtain bis((N,N-diethyl)amino)vinylphosphine; under anhydrous and oxygen-free conditions, bis(diethylamine)-vinylphosphine and phosphorus oxychloride are mixed in a mass ratio of 1.8:2.44, stirred at room temperature for 15 minutes, and then cooled to -78°C to obtain dichloro(vinyl)phosphine.

[0007] As an optimization, the polypropylene grade in step (1) is K1003.

[0008] As an optimization, the pre-modified polypropylene in step (1) needs to be stored under anhydrous and oxygen-free conditions.

[0009] As an optimization, the preparation method of the pretreated montmorillonite in step (3) is as follows: the pH of a 90 wt% ethanol solution is adjusted to 4 using acetic acid, trimethoxy(4-methoxyphenyl)silane and the ethanol solution are mixed at a mass ratio of 1:30 for 4 hours, and then montmorillonite in an amount 1.3 times the mass of trimethoxy(4-methoxyphenyl)silane is added, the temperature is raised to 70°C, and the mixture is refluxed for reaction for 24 hours. After the reaction is completed, the pretreated montmorillonite is obtained by filtering, washing, and drying.

[0010] As an optimization, the vinyl magnesium bromide solution is obtained by mixing vinyl magnesium bromide and tetrahydrofuran, the concentration of vinyl magnesium bromide is 1 mol / L, and the amount of vinyl magnesium bromide solution added is 0.4 times the volume of tetrahydrofuran.

[0011] As an optimization, the montmorillonite is industrial grade sodium-based montmorillonite.

[0012] The present invention also provides a high barrier polypropylene material prepared according to the method for preparing the high barrier polypropylene material.

[0013] The present invention also provides an application of a high barrier polypropylene material prepared according to the method for preparing the high barrier polypropylene material in an organic silica gel sealing packaging material.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: when preparing the high barrier polypropylene material, firstly, polypropylene is grafted with dichloro(vinyl)phosphine and vinylmethylsilane, and then reacted with 1-vinyl-1H-pyrrole to obtain modified polypropylene; secondly, pretreated montmorillonite is demethylated by aluminum chloride, and then reacted with 2-chloro-5-(1H-pyrrol-1-yl)pyridine and N-triethyl-(4-vinylbenzyl)ammonium to obtain modified montmorillonite; finally, the modified polypropylene and the modified montmorillonite are mixed to obtain the high barrier polypropylene material.

[0015] First, under the action of an initiator, dichloro(vinyl)phosphine, vinylmethylsilane and polypropylene are grafted, and then vinylpyrrole is grafted through the reaction of phosphorus chloride and 1-vinyl-1H-pyrrole. The phosphorus, silicon and nitrogen elements have a good synergistic flame retardant effect. Secondly, montmorillonite is a layered silicate with good barrier properties. The trimethoxy(4-methoxyphenyl)silane-modified montmorillonite carries a benzyloxy group, which can be demethylated to generate a phenolic hydroxyl group under the action of aluminum chloride. The phenolic hydroxyl group and 2-chloro-5-(1H-pyrrol-1-yl)pyridine undergo a Friedel-Crafts alkylation reaction, and the pyrrolepyridine group is grafted at the ortho position of the phenolic hydroxyl group. The nitrogen on the pyridine and the hydroxyl on the ortho-benzene ring form an intramolecular chelate ring, which can transfer light energy when exposed to ultraviolet light. Converted into heat energy, thereby achieving anti-ultraviolet aging performance; then reacted with N-triethyl-(4-vinylbenzyl)ammonium to obtain modified montmorillonite, N-triethyl-(4-vinylbenzyl)ammonium is a quaternary ammonium salt with good antibacterial properties, which can be intercalated into montmorillonite through ion exchange reaction to increase the interlayer spacing of montmorillonite; finally, modified polypropylene, modified montmorillonite and chloroplatinic acid are mixed, and under the catalysis of chloroplatinic acid, the vinyl on the vinylpyrrole of the polypropylene side chain can undergo silylation with the silicon hydrogen on the polypropylene side chain, so that the modified polypropylene is self-crosslinked, and the silicon hydrogen on the polypropylene side chain can also undergo silylation with the double bond on the N-triethyl-(4-vinylbenzyl)ammonium between the montmorillonite layers, further improving the crosslinking density, enhancing the barrier properties while also enhancing the mechanical properties. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] The polypropylene grade of the following examples and comparative examples is K1003, purchased from Yanshan Petrochemical Company; the montmorillonite is industrial grade sodium montmorillonite with a mesh size of 325 meshes; the vinyl magnesium bromide solution is obtained by mixing vinyl magnesium bromide and tetrahydrofuran, the concentration of vinyl magnesium bromide is 1 mol / L, and the amount of vinyl magnesium bromide solution added is 0.4 times the volume of tetrahydrofuran.

[0018] Example 1 A method for preparing a high barrier polypropylene material, the method comprising the following steps: (1) Bis((N,N-diethyl)amino)chlorophosphine and tetrahydrofuran were mixed in a mass ratio of 21.07:250, cooled to -78°C, added with vinylmagnesium bromide solution, heated to room temperature and stirred for 12 h, concentrated under vacuum, then added with pentane (0.6 times the volume of tetrahydrofuran), filtered and retained the filtrate, and then concentrated under vacuum and fractionated to obtain bis((N,N-diethyl)amino)vinylphosphine; under anhydrous and oxygen-free conditions, bis(diethylamino)-vinylphosphine and trichloromethane were mixed. Oxygen and phosphorus are mixed in a mass ratio of 1.8:2.44, stirred at room temperature for 15 minutes, and then cooled to -78°C to obtain dichloro(vinyl)phosphine; under anhydrous and oxygen-free conditions, polypropylene, toluene, dichloro(vinyl)phosphine, benzoyl peroxide, and vinylmethylsilane are mixed in a mass ratio of 1:50:0.2:0.01:0.2, heated to 70°C for reaction for 8 hours, and after the reaction is completed, pre-modified polypropylene is obtained by vacuum rotary evaporation; the pre-modified polypropylene needs to be stored under anhydrous and oxygen-free conditions; (2) Under anhydrous and oxygen-free conditions, pre-modified polypropylene, toluene, aluminum chloride, and 1-ethylene-1H-pyrrole were mixed in a mass ratio of 1:50:0.03:0.6, heated to 80°C and reacted for 6 hours. After the reaction, ethanol 4 times the volume of toluene was added, filtered, and dried under vacuum for 12 hours to obtain modified polypropylene; (3) Using acetic acid to adjust the pH of 90wt% ethanol solution to 4, trimethoxy(4-methoxyphenyl)silane and ethanol solution were mixed at a mass ratio of 1:30 for 4 hours, and then montmorillonite with a mass of 1.3 times that of trimethoxy(4-methoxyphenyl)silane was added, and the temperature was raised to 70°C for reflux reaction for 24 hours. After the reaction, the pretreated montmorillonite was filtered, washed and dried to obtain pretreated montmorillonite; the pretreated montmorillonite, aluminum chloride and toluene were mixed at a mass ratio of 1:0.7:50 and heated to 80°C for reaction for 6 hours. After the reaction, the mixture was filtered and washed with pure water 4 times, and dried at room temperature for 12 hours to obtain pre-modified montmorillonite; (4) Pre-modified montmorillonite, 2-chloro-5-(1H-pyrrol-1-yl)pyridine, aluminum chloride and toluene were mixed in a mass ratio of 1:0.7:0.1:50, heated to 70°C and stirred for 6 min, then heated to 100°C and reacted for 4 h. After the reaction, the mixture was filtered and washed with pure water 4 times to obtain pyridinepyrrolyl montmorillonite. Pyridinepyrrolyl montmorillonite and pure water were mixed in a mass ratio of 1:30, 0.2 times the mass of pyridinepyrrolyl montmorillonite was added with N-triethyl-(4-vinylbenzyl)ammonium chloride, stirred for 10 min, heated to 90°C and continued to react for 4 h. After the reaction, the mixture was filtered and washed with pure water 4 times to obtain modified montmorillonite. (5) Modified polypropylene, modified montmorillonite, xylene, and chloroplatinic acid were mixed at a mass ratio of 1:0.03:50:0.003 for 30 minutes, poured into a glass mold, placed at 65°C for 48 hours, and then dried in an oven at 180°C for 30 minutes to obtain a high barrier polypropylene material.

[0019] Example 2 A method for preparing a high barrier polypropylene material, the method for preparing a high barrier polypropylene material comprising the following preparation steps: (1) Bis((N,N-diethyl)amino)chlorophosphine and tetrahydrofuran were mixed in a mass ratio of 21.07:250, cooled to -78°C, and then added with vinylmagnesium bromide solution. The mixture was heated to room temperature and stirred for 12 h. The mixture was concentrated under vacuum, and then pentane (0.6 times the volume of tetrahydrofuran) was added. The filtrate was filtered and retained. The mixture was then concentrated under vacuum and purified by fractionation to obtain bis((N,N-diethyl)amino)vinylphosphine. Bis(diethylamino)-vinylphosphine and trichlorooxygen were mixed under anhydrous and oxygen-free conditions. Phosphorus is mixed in a mass ratio of 1.8:2.44, stirred at room temperature for 15 minutes, and then cooled to -78°C to obtain dichloro(vinyl)phosphine; polypropylene, toluene, dichloro(vinyl)phosphine, benzoyl peroxide, and vinylmethylsilane are mixed in a mass ratio of 1:55:0.25:0.015:0.25 under anhydrous and oxygen-free conditions, heated to 65°C for reaction for 7 hours, and after the reaction is completed, pre-modified polypropylene is obtained by vacuum rotary evaporation; the pre-modified polypropylene needs to be stored under anhydrous and oxygen-free conditions; (2) Under anhydrous and oxygen-free conditions, pre-modified polypropylene, toluene, aluminum chloride, and 1-ethylene-1H-pyrrole were mixed in a mass ratio of 1:55:0.04:0.7, heated to 80°C and reacted for 5 hours. After the reaction, ethanol 3.5 times the volume of toluene was added, filtered, and dried under vacuum for 12 hours to obtain modified polypropylene; (3) Using acetic acid to adjust the pH of 90wt% ethanol solution to 4, trimethoxy(4-methoxyphenyl)silane and ethanol solution were mixed at a mass ratio of 1:30 for 4 hours, and then montmorillonite with a mass of 1.3 times that of trimethoxy(4-methoxyphenyl)silane was added, and the temperature was raised to 70°C for reflux reaction for 24 hours. After the reaction, the pretreated montmorillonite was filtered, washed and dried to obtain pretreated montmorillonite; the pretreated montmorillonite, aluminum chloride and toluene were mixed at a mass ratio of 1:0.8:55 and heated to 75°C for reaction for 5.5 hours. After the reaction, the mixture was filtered and washed with pure water for 3 times, and dried at room temperature for 12 hours to obtain pre-modified montmorillonite; (4) Pre-modified montmorillonite, 2-chloro-5-(1H-pyrrol-1-yl)pyridine, aluminum chloride and toluene were mixed in a mass ratio of 1:0.8:0.15:55, heated to 65°C and stirred for 5 min, then heated to 97°C for reaction for 3.5 h. After the reaction was completed, the mixture was filtered and washed with pure water three times to obtain pyridinepyrrolyl montmorillonite; pyridinepyrrolyl montmorillonite and pure water were mixed in a mass ratio of 1:30, 0.25 times the mass of pyridinepyrrolyl montmorillonite was added with N-triethyl-(4-vinylbenzyl)ammonium chloride, stirred for 10 min, heated to 90°C and continued to react for 4 h. After the reaction was completed, the mixture was filtered and washed with pure water three times to obtain modified montmorillonite; (5) Modified polypropylene, modified montmorillonite, xylene, and chloroplatinic acid were mixed at a mass ratio of 1:0.04:55:0.003 for 25 minutes, poured into a glass mold, placed at 65°C for 48 hours, and then dried in an oven at 180°C for 25 minutes to obtain a high barrier polypropylene material.

[0020] Example 3 A method for preparing a high barrier polypropylene material, the method for preparing a high barrier polypropylene material comprising the following preparation steps: (1) Bis((N,N-diethyl)amino)chlorophosphine and tetrahydrofuran were mixed in a mass ratio of 21.07:250, cooled to -78°C, added with vinylmagnesium bromide solution, heated to room temperature and stirred for 12 h, concentrated under vacuum, then added with pentane (0.6 times the volume of tetrahydrofuran), filtered and retained the filtrate, and then concentrated under vacuum and fractionated to obtain bis((N,N-diethyl)amino)vinylphosphine; under anhydrous and oxygen-free conditions, bis(diethylamino)-vinylphosphine and trichloromethane were mixed. Oxygen and phosphorus are mixed in a mass ratio of 1.8:2.44, stirred at room temperature for 15 minutes, and then cooled to -78°C to obtain dichloro(vinyl)phosphine; under anhydrous and oxygen-free conditions, polypropylene, toluene, dichloro(vinyl)phosphine, benzoyl peroxide, and vinylmethylsilane are mixed in a mass ratio of 1:60:0.3:0.02:0.3, heated to 60°C for reaction for 6 hours, and after the reaction is completed, pre-modified polypropylene is obtained by vacuum rotary evaporation; the pre-modified polypropylene needs to be stored under anhydrous and oxygen-free conditions; (2) Under anhydrous and oxygen-free conditions, pre-modified polypropylene, toluene, aluminum chloride, and 1-ethylene-1H-pyrrole were mixed in a mass ratio of 1:60:0.05:0.8, heated to 80°C and reacted for 4 hours. After the reaction, ethanol 3 times the volume of toluene was added, filtered, and dried under vacuum for 12 hours to obtain modified polypropylene; (3) Using acetic acid to adjust the pH of 90wt% ethanol solution to 4, trimethoxy(4-methoxyphenyl)silane and ethanol solution were mixed at a mass ratio of 1:30 for 4 hours, and then montmorillonite with a mass of 1.3 times that of trimethoxy(4-methoxyphenyl)silane was added, and the temperature was raised to 70°C for reflux reaction for 24 hours. After the reaction, the pretreated montmorillonite was filtered, washed and dried to obtain pretreated montmorillonite; the pretreated montmorillonite, aluminum chloride and toluene were mixed at a mass ratio of 1:0.9:60 and heated to 70°C for reaction for 5 hours. After the reaction, the mixture was filtered and washed with pure water for 3 times, and dried at room temperature for 12 hours to obtain pre-modified montmorillonite; (4) Pre-modified montmorillonite, 2-chloro-5-(1H-pyrrol-1-yl)pyridine, aluminum chloride and toluene were mixed in a mass ratio of 1:0.9:0.2:60, heated to 60°C and stirred for 5 min, then heated to 95°C for reaction for 3 h, filtered after the reaction and washed with pure water 3 times to obtain pyridine pyrrolyl montmorillonite; pyridine pyrrolyl montmorillonite and pure water were mixed in a mass ratio of 1:30, 0.3 times the mass of pyridine pyrrolyl montmorillonite was added with N-triethyl-(4-vinylbenzyl)ammonium chloride, stirred for 10 min, heated to 90°C and continued to react for 4 h, filtered after the reaction and washed with pure water 3 times to obtain modified montmorillonite; (5) Modified polypropylene, modified montmorillonite, xylene, and chloroplatinic acid were mixed at a mass ratio of 1:0.05:60:0.003 for 20 minutes, poured into a glass mold, placed at 65°C for 48 hours, and then dried in an oven at 180°C for 20 minutes to obtain a high barrier polypropylene material.

[0021] Comparative Example 1: The preparation method of the high barrier polypropylene material of Comparative Example 1 differs from that of Example 2 in that step (1) is not included, and step (5) is modified as follows: polypropylene, modified montmorillonite and xylene are mixed at a mass ratio of 1:0.04:55 for 25 minutes, poured into a glass mold, placed at 65° C. for 48 hours, and then dried in an oven at 180° C. for 25 minutes to obtain a high barrier polypropylene material.

[0022] Comparative Example 2: The preparation method of the high barrier polypropylene material of Comparative Example 2 differs from that of Example 2 in that step (5) is modified as follows: modified polypropylene, modified montmorillonite and xylene are mixed at a mass ratio of 1:0.04:55 for 25 minutes, poured into a glass mold, placed at 65°C for 48 hours, and then dried in an oven at 180°C for 25 minutes to obtain a high barrier polypropylene material.

[0023] Comparative Example 3: The preparation method of the high barrier polypropylene material of Comparative Example 3 differs from that of Example 2 in that step (3) is not included, and step (4) is modified as follows: montmorillonite and pure water are mixed in a mass ratio of 1:30, 0.25 times the mass of montmorillonite of N-triethyl-(4-vinylbenzyl)ammonium chloride is added, and after stirring for 10 minutes, the temperature is raised to 90° C. and the reaction is continued for 4 hours. After the reaction is completed, the modified montmorillonite is filtered and washed with pure water three times to obtain the modified montmorillonite.

[0024] Test Example 1: Flame retardant performance test: Test method: The high barrier polypropylene materials prepared in the examples and comparative examples were tested for limiting oxygen index using a JF-3 instrument. The size of the polypropylene material was 100 mm×6.5 mm×3.2 mm. The results are shown in Table 1.

[0025]

[0026] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the high barrier polypropylene material prepared in the present invention has good flame retardant properties.

[0027] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 1, indicating that under the action of the initiator, dichloro(vinyl)phosphine, vinylmethylsilane and polypropylene are grafted, and then vinylpyrrole is grafted through the reaction of phosphine chloride and 1-ethylene-1H-pyrrole, and phosphorus, silicon and nitrogen have a good synergistic flame retardant effect.

[0028] Test Example 2: Barrier performance test: Test method: Referring to the standard GB / T26253-2010, the water vapor transmission rate was measured on a permatran-w3 / 61 type moisture permeability tester. The polypropylene materials prepared in the examples and comparative examples were cut into circular shapes with a thickness of 30 μm and a test area of ​​10 cm. 2 , the test humidity was 90% and the temperature was 40℃. The results are shown in Table 2.

[0029]

[0030] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 2, it can be found that the high barrier polypropylene material prepared in the present invention has good barrier properties.

[0031] By comparison, the water vapor permeability of Examples 1 to 3 is lower than that of Comparative Examples 1 to 3, indicating that when the modified polypropylene, modified montmorillonite and chloroplatinic acid are mixed, the vinyl on the vinylpyrrole of the polypropylene side chain can undergo silylation with the silane on the polypropylene side chain under the catalysis of chloroplatinic acid, so that the modified polypropylene is self-crosslinked, and the silane on the polypropylene side chain can also undergo silylation with the double bond on N-triethyl-(4-vinylbenzyl)ammonium between montmorillonite layers, thereby further improving the crosslinking density, enhancing the barrier properties and the mechanical properties at the same time.

[0032] Test Example 3: Mechanical properties test: Test method: According to GB / T1040-92 standard, the examples and comparative examples were prepared into dumbbell-shaped specimens with dimensions of 150 mm×20 mm×4 mm, and the tensile rate was 20 mm / min. The results are shown in Table 3.

[0033] Test of anti-ultraviolet aging performance: Test method: The high barrier polypropylene materials prepared in the examples and comparative examples were placed in a UV light box. There were 4 Q-LabUVA340 UV lamps in the light box. The distance between the lamps was 10 cm. The distance between the sample and the lamp was 5 cm. The central wavelength of the UV light was 340 nm and the intensity was 13 mW / cm 2 The size of the light box is 130cm*45cm*20cm, and the irradiation time is 720h. After the irradiation, the tensile strength is tested according to the mechanical property test method and the tensile strength retention rate before and after ultraviolet irradiation is calculated. The results are shown in Table 3.

[0034]

[0035] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 3, it can be found that the high barrier polypropylene material prepared in the present invention has good mechanical properties and anti-ultraviolet aging properties.

[0036] The tensile strength of Examples 1 to 3 is greater than that of Comparative Examples 1 to 2, and the tensile strength retention rate of Examples 1 to 3 is greater than that of Comparative Example 3, indicating that first, under the action of an initiator, dichloro(vinyl)phosphine, vinylmethylsilane and polypropylene are grafted, and then vinylpyrrole is grafted by further reacting phosphine chloride with 1-vinyl-1H-pyrrole; the montmorillonite modified with trimethoxy(4-methoxyphenyl)silane carries a benzyloxy group, which can be demethylated to generate a phenolic hydroxyl group under the action of aluminum chloride, and the phenolic hydroxyl group undergoes a Friedel-Crafts alkylation reaction with 2-chloro-5-(1H-pyrrol-1-yl)pyridine, and the pyrrole-pyridine group is grafted. At the ortho position of the phenolic hydroxyl group, the nitrogen on the pyridine and the hydroxyl group on the ortho benzene ring form an intramolecular chelate ring, which can convert light energy into heat energy when exposed to ultraviolet light, thereby achieving anti-ultraviolet aging performance; finally, the modified polypropylene, modified montmorillonite and chloroplatinic acid are mixed, and under the catalysis of chloroplatinic acid, the vinyl on the vinylpyrrole of the polypropylene side chain can undergo silylation with the silane on the polypropylene side chain, so that the modified polypropylene is self-crosslinked, and the silane on the polypropylene side chain can also undergo silylation with the double bond on the N-triethyl-(4-vinylbenzyl)ammonium between the montmorillonite layers, further improving the crosslinking density, enhancing the barrier properties while also enhancing the mechanical properties.

[0037] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing a high barrier polypropylene material, characterized in that: The method comprises the following preparation steps: (1) Under anhydrous and oxygen-free conditions, polypropylene, toluene, dichloro(vinyl)phosphine, benzoyl peroxide, and vinylmethylsilane are mixed in a mass ratio of 1: (50-60): (0.2-0.3): (0.01-0.02): (0.2-0.3), and the mixture is heated to 60-70°C for reaction for 6-8 hours. After the reaction is completed, pre-modified polypropylene is obtained by vacuum rotary evaporation; (2) Under anhydrous and oxygen-free conditions, pre-modified polypropylene, toluene, aluminum chloride, and 1-ethylene-1H-pyrrole are mixed in a mass ratio of 1: (50-60): (0.03-0.05): (0.6-0.8), and the mixture is heated to 80° C. and reacted for 4-6 hours. After the reaction, ethanol in an amount 3-4 times the volume of toluene is added, and the mixture is filtered and dried under vacuum for 12 hours to obtain modified polypropylene; (3) Pretreated montmorillonite, aluminum chloride and toluene are mixed in a mass ratio of 1: (0.7-0.9): (50-60) and heated to 70-80°C for reaction for 5-6 hours. After the reaction, the mixture is filtered and washed with pure water for 3-4 times, and dried at room temperature for 12 hours to obtain pre-modified montmorillonite; (4) Pre-modified montmorillonite, 2-chloro-5-(1H-pyrrol-1-yl)pyridine, aluminum chloride and toluene are mixed in a mass ratio of 1: (0.7-0.9): (0.1-0.2): (50-60), heated to 60-70°C and stirred for 5-6 minutes, then heated to 95-100°C for reaction for 3-4 hours, filtered after the reaction and washed with pure water 3-4 times to obtain pyridine pyrrolyl montmorillonite; pyridine pyrrolyl montmorillonite and pure water are mixed in a mass ratio of 1:30, 0.2-0.3 times the mass of pyridine pyrrolyl montmorillonite is added with N-triethyl-(4-vinylbenzyl)ammonium chloride, stirred for 10 minutes, heated to 90°C and continued to react for 4 hours, filtered after the reaction and washed with pure water 3-4 times to obtain modified montmorillonite; (5) Modified polypropylene, modified montmorillonite, xylene and chloroplatinic acid are mixed in a mass ratio of 1: (0.03-0.05): (50-60): 0.003 for 20-30 minutes, poured into a glass mold, placed at 65°C for 48 hours, and then dried in an oven at 180°C for 20-30 minutes to obtain a high barrier polypropylene material.

2. The method for preparing a high barrier polypropylene material according to claim 1, characterized in that: The preparation method of the dichloro(vinyl)phosphine in step (1) is as follows: bis((N,N-diethyl)amino)chlorophosphine and tetrahydrofuran are mixed in a mass ratio of 21.07:250, cooled to -78°C, added with a vinylmagnesium bromide solution, heated to room temperature and stirred for 12 hours, concentrated under vacuum, then added with pentane in an amount 0.6 times the volume of tetrahydrofuran, filtered and retained the filtrate, then concentrated under vacuum, fractionated and purified to obtain bis((N,N-diethyl)amino)vinylphosphine; under anhydrous and oxygen-free conditions, bis(diethylamine)-vinylphosphine and phosphorus oxychloride are mixed in a mass ratio of 1.8:2.44, stirred at room temperature for 15 minutes, and then cooled to -78°C to obtain dichloro(vinyl)phosphine.

3. The method for preparing a high barrier polypropylene material according to claim 1, characterized in that: The polypropylene grade in step (1) is K1003.

4. The method for preparing a high barrier polypropylene material according to claim 1, characterized in that: The pre-modified polypropylene in step (1) needs to be stored under water-free and oxygen-free conditions.

5. The method for preparing a high barrier polypropylene material according to claim 1, characterized in that: The preparation method of the pretreated montmorillonite in step (3) is as follows: the pH of a 90 wt% ethanol solution is adjusted to 4 using acetic acid, trimethoxy (4-methoxyphenyl) silane and the ethanol solution are mixed at a mass ratio of 1:30 for 4 hours, and then montmorillonite of 1.3 times the mass of trimethoxy (4-methoxyphenyl) silane is added, the temperature is raised to 70° C. and refluxed for reaction for 24 hours, and after the reaction is completed, the pretreated montmorillonite is obtained by filtering, washing, and drying.

6. The method for preparing a high barrier polypropylene material according to claim 2, characterized in that: The vinyl magnesium bromide solution is obtained by mixing vinyl magnesium bromide and tetrahydrofuran, the concentration of vinyl magnesium bromide is 1 mol / L, and the amount of vinyl magnesium bromide solution added is 0.4 times the volume of tetrahydrofuran.

7. The method for preparing a high barrier polypropylene material according to claim 5, characterized in that: The montmorillonite is industrial grade sodium-based montmorillonite.

8. A high barrier polypropylene material prepared according to the method for preparing a high barrier polypropylene material according to any one of claims 1 to 7.

9. Use of the high barrier polypropylene material prepared by the method for preparing the high barrier polypropylene material according to any one of claims 1 to 7 in organic silicone sealing packaging materials.

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