Polypropylene material for organic silicon product packaging bottle and preparation method of polypropylene material

Abstract

The invention relates to the technical field of high polymer materials, and discloses a polypropylene material for an organic silicon product packaging bottle and a preparation method of the polypropylene material. The preparation method of the polypropylene material for the organic silicon product packaging bottle comprises the following steps: sequentially reacting polypropylene with a modifier and o-vanillin to obtain modified polypropylene; 4-amino-2, 2, 6, 6-tetramethylpiperidine is combined with the surface modified nanometer titanium dioxide, and modified nanometer titanium dioxide is obtained; and mixing the modified nano titanium dioxide, the modified polypropylene and the functionalized montmorillonite, carrying out melt blending, and extruding to obtain the polypropylene material for the organic silicon product packaging bottle. The polypropylene material provided by the invention has excellent mechanical properties, ultraviolet aging resistance, thermo-oxidative aging resistance and barrier property, can be used in organic silicon product packaging bottle materials, and improves the storage stability and safety of organic silicon products.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, in particular to a polypropylene material for packaging bottles of organosilicon products and a preparation method thereof. Background Art

[0002] Silicone products are primarily used for sealing, bonding, lubrication, coating, surface activity, mold release, defoaming, foam suppression, waterproofing, moisture resistance, and inert fillers. With the continued growth in the number and variety of silicones, their application areas are constantly expanding, forming a unique and important product system in the chemical new materials industry. Many varieties are irreplaceable and indispensable to other chemicals.

[0003] During storage, the performance of silicone products may be affected by external factors (water vapor, oxygen, ultraviolet rays, high temperature, etc.). To ensure the storage stability of silicone products, silicone packaging materials must have excellent barrier properties. At the same time, to prevent silicone product leakage caused by damage to the packaging material due to external forces, it is also very important to improve the mechanical properties of the packaging material. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for preparing a polypropylene material for packaging bottles of organosilicon products, comprising the following steps: Step (1) glycidyl methacrylate reacts with ethylenediamine to obtain a modifier; polypropylene reacts with the modifier and o-vanillin in sequence to obtain modified polypropylene; Step (2) nano-titanium dioxide reacts with a silane coupling agent KH-550 to obtain surface-modified nano-titanium dioxide; terephthaloyl chloride is used as a cross-linking agent to combine 4-amino-2,2,6,6-tetramethylpiperidine with the surface-modified nano-titanium dioxide to obtain modified nano-titanium dioxide; Step (3) The modified nano titanium dioxide, modified polypropylene and functionalized montmorillonite are mixed, melt-blended and extruded to obtain polypropylene material for packaging bottles of silicone products.

[0005] Preferably, in the step (1), during the preparation of the modifier, the reaction conditions of glycidyl methacrylate and ethylenediamine are as follows: glycidyl methacrylate and ethylenediamine are mixed in an equal molar ratio and stirred at room temperature for 22-26 hours.

[0006] Preferably, in the step (1), the preparation method of the modified polypropylene specifically comprises: adding a modifier and benzoyl peroxide to xylene in a nitrogen atmosphere, stirring for 20-40 minutes, then adding polypropylene particles, heating to 85-95°C and stirring for reaction for 5-7 hours, purifying, and obtaining surface-modified polypropylene; wherein the mass ratio of the modifier, benzoyl peroxide, xylene, and polypropylene particles is (1.1-1.7): (0.06-0.08): (100-150): (20-30); adding o-vanillin to xylene, stirring, then adding the surface-modified polypropylene, heating to 60-80°C and reacting for 10-12 hours. h, purified to obtain modified polypropylene; wherein, the mass ratio of o-vanillin, xylene, and surface-modified polypropylene is (0.08-0.12): (120-150): (25-35); in the above process, the epoxy group of glycidyl methacrylate reacts with the amino group at one end of ethylenediamine to obtain a modifier containing a carbon-carbon double bond and an amino group, and then, under the initiation of benzoyl peroxide, the modifier reacts with polypropylene to obtain surface-modified polypropylene containing an amino functional group in the side chain; further, the amino group of the surface-modified polypropylene reacts with the aldehyde group of o-vanillin to undergo a Schiff base reaction, thereby introducing the o-vanillin structure into the polypropylene, thereby improving the anti-ultraviolet oxidation performance of the polypropylene.

[0007] Preferably, in step (2), the preparation method of the surface-modified nano-titanium dioxide specifically comprises: mixing a silane coupling agent KH-550 and a 95% by volume ethanol / water mixture in a mass ratio of (4-6):95, adjusting the pH of the mixed system to 3.5-4.5 with acetic acid, and hydrolyzing at room temperature for 1 hour to obtain a silane coupling agent hydrolyzate; mixing nano-titanium dioxide and the above-mentioned silane coupling agent hydrolyzate in a mass ratio of (5-8):(400-450), ultrasonicating, and then reacting at 48-52°C for 80-100 minutes, and purifying to obtain surface-modified nano-titanium dioxide.

[0008] Preferably, in the step (2), the preparation method of the modified nano titanium dioxide specifically comprises: mixing surface-modified nano titanium dioxide, 4-amino-2,2,6,6-tetramethylpiperidine, triethylamine, and dichloromethane at room temperature, ultrasonicating, and continuing to stir at 3-5°C, and then dripping a terephthaloyl chloride / dichloromethane mixture with a mass fraction of 11.8%, and completing the dripping within 1-1.5 hours, stirring the mixed system at room temperature for 1.5-2.5 hours, and purifying to obtain modified nano titanium dioxide; wherein, the surface-modified nano titanium dioxide, 4-amino-2,2 The mass ratio of 6,6-tetramethylpiperidine, triethylamine, dichloromethane, and terephthaloyl chloride / dichloromethane mixture is (1-3): (2-4): (7.3-14.6): (30-50): (30-60); in the above process, nano-titanium dioxide is treated with silane coupling agent KH-550, and amino groups are introduced on its surface to obtain surface-modified nano-titanium dioxide, and then terephthaloyl chloride is used as a cross-linking agent, and the acyl chloride groups at both ends of terephthaloyl chloride react with the amino groups of surface-modified nano-titanium dioxide and 4-amino-2,2,6,6-tetramethylpiperidine to form amide bonds. The 4-amino-2,2,6,6-tetramethylpiperidine structure is connected to nano-titanium dioxide. As an inorganic filler, nano-titanium dioxide itself has good thermal stability and UV resistance, which can improve the UV aging resistance and thermal oxidation aging resistance of polypropylene materials. At the same time, nano-titanium dioxide can also be used as a nucleating agent to promote the crystallization of polypropylene and improve the strength of polypropylene materials. The aromatic amide bond introduced on the modified nano-titanium dioxide promotes the crystallization of polypropylene, refines the grains, and induces partial β-phase crystallization, thereby improving the strength, toughness and thermal stability of polypropylene materials. In addition, β-phase polypropylene has It has a lamellar structure parallel to the direction of airflow, which can extend the passage path of gas and liquid, thereby improving the barrier properties of polypropylene materials; in addition, the hindered amine structure of 4-amino-2,2,6,6-tetramethylpiperidine can improve the ultraviolet aging resistance and thermal oxidation aging resistance of polypropylene materials; further, by modifying the nano-titanium dioxide and introducing organic functional groups on its surface, the dispersibility of the nano-titanium dioxide is improved, making it more effective, and the modified nano-titanium dioxide particles play an active role in filling the pores of the matrix, thereby further improving the barrier properties of the polypropylene material.

[0009] Preferably, in step (3), the mass ratio of the modified nano-titanium dioxide, modified polypropylene, and functionalized montmorillonite is (3-7):100:(2-5).

[0010] Preferably, in step (3), the melt blending conditions are: melt blending at 170-190°C for 4-10 minutes.

[0011] Furthermore, in step (3), the preparation method of the functionalized montmorillonite is as follows: pretreated montmorillonite and 1,2-epoxy-9-decene are added to N,N-dimethylformamide, stirred, and then ammonium persulfate is added. The mixture is reacted at 55-70°C in a nitrogen atmosphere for 2-5 hours, and purified to obtain functionalized montmorillonite; wherein the mass ratio of N,N-dimethylformamide, pretreated montmorillonite, 1,2-epoxy-9-decene, and ammonium sulfate is (20-40):1:(0.3-0.5):(0.02-0.04).

[0012] Furthermore, the preparation method of the pretreated montmorillonite is as follows: montmorillonite is mixed with a 90% by volume ethanol / water mixture, ultrasonicated, the pH of the mixture is adjusted to 3-4 by a 1 mol / L hydrochloric acid aqueous solution, and then a silane coupling agent KH-570 is added, and the mixture is stirred at 70-75°C for 5-6 hours, and purified to obtain pretreated montmorillonite; wherein the mass ratio of montmorillonite, ethanol / water mixture, and silane coupling agent KH-570 is 1:400:(0.02-0.05); in the above process, montmorillonite is an inorganic filler with a lamellar structure, which can improve the mechanical strength, thermal stability and resistance of the polymer matrix. The montmorillonite has good barrier properties, and the lamellar structure of montmorillonite can reflect sunlight and has anti-ultraviolet effect. The silane coupling agent KH-570 is used to introduce carbon-carbon double bonds into montmorillonite to obtain pretreated montmorillonite, and then under the initiation action of the initiator ammonium persulfate, the pretreated montmorillonite and 1,2-epoxy-9-decene are reacted to introduce alkyl long chains containing epoxy groups into the montmorillonite. The alkyl long chains have good flexibility, and the epoxy groups can react with the amino groups on the modified polypropylene side chains to crosslink, thereby increasing the crosslinking density of the polypropylene system and improving the dispersibility of the montmorillonite, thereby improving the strength, toughness, barrier properties, anti-ultraviolet aging properties and anti-thermal oxidative aging properties of the polypropylene material.

[0013] The present invention also discloses a polypropylene material for packaging bottles of organic silicon products, which is prepared by adopting the above-mentioned method for preparing the polypropylene material for packaging bottles of organic silicon products.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention prepares a modifier by reacting the epoxy group of glycidyl methacrylate with ethylenediamine, and then modifies polypropylene with the modifier and o-vanillin. Amino functional groups and o-vanillin structures are introduced into the side chains of polypropylene. The amino functional groups can combine with modified nano-titanium dioxide and functionalized montmorillonite through hydrogen bonds or chemical bonds, thereby promoting the dispersion of the modified nano-titanium dioxide and functionalized montmorillonite. The o-vanillin structure improves the UV aging resistance of the polypropylene material. 2. The present invention uses modified nano-titanium dioxide as a filler for polypropylene materials. The modified nano-titanium dioxide plays multiple roles: (1) as an inorganic filler to improve the mechanical strength and thermal oxidation aging resistance of polypropylene materials; (2) as a nucleating agent to improve crystallization and induce partial β-phase crystallization, thereby improving the strength, toughness, thermal stability and barrier properties of polypropylene materials; (3) synergistically with the hindered amine structure of 4-amino-2,2,6,6-tetramethylpiperidine to improve the UV aging resistance and thermal oxidation aging resistance of polypropylene materials; (4) filling the pores of the matrix, thereby further improving the barrier properties of the polypropylene material; 3. The present invention further adds functionalized montmorillonite to the polypropylene material. The montmorillonite can improve the strength, thermal stability, barrier properties and UV aging resistance of the polypropylene material. The presence of long alkyl chains and epoxy groups in the functionalized montmorillonite increases the crosslinking density of the polypropylene system, improves the dispersibility of the montmorillonite, and improves the overall performance of the polypropylene material.

[0015] In summary, under the combined action of modified polypropylene, modified nano-titanium dioxide, and functionalized montmorillonite, the polypropylene material of the present invention has excellent mechanical properties, resistance to ultraviolet aging, resistance to thermal oxidative aging, and barrier properties, and can be used in packaging bottles for silicone products to improve the storage stability and safety of silicone products. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a comparison chart of tensile strength tests before and after aging of polypropylene materials for silicone product packaging bottles prepared in Examples 2-4 of the present invention and Comparative Examples 1-3; Figure 2 This is a comparison chart of the impact strength test of polypropylene materials for silicone product packaging bottles prepared in Examples 2-4 of the present invention and Comparative Examples 1-3 before and after aging; Figure 3 It is a comparison chart of the water vapor transmission rate test of the polypropylene material for the packaging bottle of the silicone product prepared in Examples 2-4 of the present invention and Comparative Examples 1-3. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all 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.

[0018] Example 1 This embodiment discloses a method for preparing functionalized montmorillonite, comprising the following steps: mixing montmorillonite with a 90% by volume ethanol / water mixture, ultrasonically dispersing for 1 hour, adjusting the pH of the mixture to 3.5 with a 1 mol / L hydrochloric acid aqueous solution, adding a silane coupling agent KH-570, and stirring the mixture at 72°C for 5.5 hours. After the reaction is complete, filtering, washing, and drying to obtain pretreated montmorillonite; wherein the montmorillonite, the ethanol / water mixture, and the silane coupling agent KH-570 are mixed. The mass ratio of 570 is 1:400:0.03; the pretreated montmorillonite and 1,2-epoxy-9-decene are added to N,N-dimethylformamide, stirred for 30 minutes, and then ammonium persulfate is added. The mixture is reacted at 67°C in a nitrogen atmosphere for 3.5 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain functionalized montmorillonite; wherein the mass ratio of N,N-dimethylformamide, pretreated montmorillonite, 1,2-epoxy-9-decene, and ammonium sulfate is 30:1:0.4:0.03.

[0019] Example 2 This embodiment discloses a method for preparing a polypropylene material for packaging bottles of organosilicon products, comprising the following steps: Step (1) mixing glycidyl methacrylate and ethylenediamine in equal molar ratios, adding them to methanol, stirring and reacting at room temperature for 22 hours, and evaporating the solvent after the reaction is completed to obtain a modifier; adding the modifier and benzoyl peroxide to xylene in a nitrogen atmosphere, stirring for 20 minutes, then adding polypropylene particles, heating to 85°C and stirring and reacting for 7 hours, after the reaction is completed, purging with nitrogen, filtering, washing, and drying to obtain surface-modified polypropylene; wherein the mass ratio of the modifier, benzoyl peroxide, xylene, and polypropylene particles is 1.1:0.06:100:20; adding o-vanillin to xylene, stirring for 20 minutes, then adding surface-modified polypropylene, heating to 60°C and reacting for 12 hours, after the reaction is completed, filtering, washing, and drying to obtain modified polypropylene; wherein the mass ratio of o-vanillin, xylene, and surface-modified polypropylene is 0.08:120:25; Step (2) adding silane coupling agent KH-550 to a 95% by volume ethanol / water mixture, adjusting the pH of the mixture to 3.5 with acetic acid, and hydrolyzing at room temperature for 1 hour to obtain a silane coupling agent hydrolyzate; wherein the mass ratio of silane coupling agent KH-550 to the ethanol / water mixture is 4:95; adding 5g of nano-titanium dioxide to 400g of the above-mentioned silane coupling agent hydrolyzate, ultrasonically treating for 10min, and then reacting at 48°C for 100min. After the reaction is completed, filtering, and washing the obtained filter residue with ethanol and deionized water in turn, and drying at 80°C to obtain surface-modified nano-titanium dioxide; at room temperature, 1g of surface-modified nano-titanium dioxide and 2g of 4-amino-2,2,6,6-tetramethylpiperidine, 7.3g triethylamine, and 30g dichloromethane were mixed and ultrasonically treated for 30 minutes. Stirring was continued at 3°C, and then 30g of a 11.8% mass fraction of terephthaloyl chloride / dichloromethane mixture was added dropwise within 1 hour. The mixture was stirred and reacted at room temperature for 1.5 hours. After the reaction was completed, it was filtered and the obtained solid product was added to 20g of a 0.04g / L sodium hydroxide aqueous solution. Stirring was continued for 1 hour and centrifuged. The obtained precipitate was washed with deionized water and dried at 80°C to obtain modified nano-titanium dioxide. Step (3) The modified nano-titanium dioxide, modified polypropylene and functionalized montmorillonite are mixed in a mass ratio of 3:100:2, melt-blended at 170° C. for 10 minutes, and extruded to obtain a polypropylene material for packaging bottles of silicone products.

[0020] Example 3 This embodiment discloses a method for preparing a polypropylene material for packaging bottles of organosilicon products, comprising the following steps: Step (1) mixing glycidyl methacrylate and ethylenediamine in equal molar ratios, adding them to methanol, stirring and reacting at room temperature for 26 hours, and evaporating the solvent after the reaction is completed to obtain a modifier; adding the modifier and benzoyl peroxide to xylene in a nitrogen atmosphere, stirring for 40 minutes, then adding polypropylene particles, heating to 95°C and stirring and reacting for 5 hours, after the reaction is completed, purging with nitrogen, filtering, washing, and drying to obtain surface-modified polypropylene; wherein the mass ratio of the modifier, benzoyl peroxide, xylene, and polypropylene particles is 1.7:0.08:150:30; adding o-vanillin to xylene, stirring for 40 minutes, then adding surface-modified polypropylene, heating to 80°C and reacting for 10 hours, after the reaction is completed, filtering, washing, and drying to obtain modified polypropylene; wherein the mass ratio of o-vanillin, xylene, and surface-modified polypropylene is 0.12:150:35; Step (2) adding silane coupling agent KH-550 to a 95% by volume ethanol / water mixture, adjusting the pH of the mixture to 4.5 with acetic acid, and hydrolyzing at room temperature for 1 hour to obtain a silane coupling agent hydrolyzate; wherein the mass ratio of silane coupling agent KH-550 to the ethanol / water mixture is 6:95; adding 8g of nano-titanium dioxide to 450g of the above-mentioned silane coupling agent hydrolyzate, ultrasonically treating for 20min, and then reacting at 52°C for 80min. After the reaction is completed, filtering, and washing the obtained filter residue with ethanol and deionized water in turn, and drying at 80°C to obtain surface-modified nano-titanium dioxide; at room temperature, 3g of surface-modified nano-titanium dioxide and 4g of 4-amino-2,2,6,6-tetramethylpiperidine, 14.6g triethylamine, and 50g dichloromethane were mixed and ultrasonically treated for 60min. Stirring was continued at 5°C, and then 60g of a 11.8% mass fraction of terephthaloyl chloride / dichloromethane mixture was added dropwise within 1.5h. The mixture was stirred and reacted at room temperature for 2.5h. After the reaction was completed, the mixture was filtered and the obtained solid product was added to 40g of a 0.04g / L sodium hydroxide aqueous solution. Stirring was continued for 1h and centrifuged. The obtained precipitate was washed with deionized water and dried at 80°C to obtain modified nano-titanium dioxide. Step (3) The modified nano-titanium dioxide, modified polypropylene and functionalized montmorillonite are mixed in a mass ratio of 7:100:5, melt-blended at 190° C. for 4 minutes, and extruded to obtain a polypropylene material for packaging bottles of silicone products.

[0021] Example 4 This embodiment discloses a method for preparing a polypropylene material for packaging bottles of organosilicon products, comprising the following steps: Step (1) mixing glycidyl methacrylate and ethylenediamine in equal molar ratios, adding them to methanol, stirring and reacting at room temperature for 24 hours, and after the reaction is completed, evaporating the solvent to obtain a modifier; adding the modifier and benzoyl peroxide to xylene in a nitrogen atmosphere, stirring for 30 minutes, then adding polypropylene particles, heating to 90°C and stirring and reacting for 6 hours, after the reaction is completed, purging with nitrogen, filtering, washing, and drying to obtain surface-modified polypropylene; wherein the mass ratio of the modifier, benzoyl peroxide, xylene, and polypropylene particles is 1.4:0.07:125:25; adding o-vanillin to xylene, stirring for 30 minutes, then adding surface-modified polypropylene, heating to 70°C and reacting for 11 hours, after the reaction is completed, filtering, washing, and drying to obtain modified polypropylene; wherein the mass ratio of o-vanillin, xylene, and surface-modified polypropylene is 0.1:135:30; Step (2) adding silane coupling agent KH-550 to a 95% by volume ethanol / water mixture, adjusting the pH of the mixture to 4 with acetic acid, and hydrolyzing at room temperature for 1 hour to obtain a silane coupling agent hydrolyzate; wherein the mass ratio of silane coupling agent KH-550 to the ethanol / water mixture is 5:95; adding 6.5g of nano-titanium dioxide to 425g of the above-mentioned silane coupling agent hydrolyzate, ultrasonically treating for 15min, and then reacting at 50°C for 90min. After the reaction is completed, filtering, and washing the obtained filter residue with ethanol and deionized water in turn, and drying at 80°C to obtain surface-modified nano-titanium dioxide; at room temperature, 2g of surface-modified nano-titanium dioxide and 3g of 4-amino-2,2,6,6-tetramethylpiperidine, 11g triethylamine, and 40g dichloromethane were mixed and ultrasonically treated for 45 minutes. Stirring was continued at 4°C, and then 45g of a 11.8% mass fraction of terephthaloyl chloride / dichloromethane mixture was added dropwise within 1.3 hours. The mixture was stirred and reacted at room temperature for 2 hours. After the reaction was completed, it was filtered and the obtained solid product was added to 30g of a 0.04g / L sodium hydroxide aqueous solution. Stirring was continued for 1 hour and centrifuged. The obtained precipitate was washed with deionized water and dried at 80°C to obtain modified nano-titanium dioxide. Step (3) The modified nano-titanium dioxide, modified polypropylene and functionalized montmorillonite are mixed in a mass ratio of 5:100:3.5, melt-blended at 180° C. for 7 minutes, and extruded to obtain a polypropylene material for packaging bottles of silicone products.

[0022] Comparative Example 1 This comparative example discloses a method for preparing a polypropylene material for packaging bottles of organosilicon products, comprising the following steps: Step (1) mixing glycidyl methacrylate and ethylenediamine in equal molar ratios, adding them to methanol, stirring and reacting at room temperature for 24 hours, and after the reaction is completed, evaporating the solvent to obtain a modifier; adding the modifier and benzoyl peroxide to xylene in a nitrogen atmosphere, stirring for 30 minutes, then adding polypropylene particles, heating to 90°C and stirring and reacting for 6 hours, after the reaction is completed, purging with nitrogen, filtering, washing, and drying to obtain surface-modified polypropylene; wherein the mass ratio of the modifier, benzoyl peroxide, xylene, and polypropylene particles is 1.4:0.07:125:25; adding o-vanillin to xylene, stirring for 30 minutes, then adding surface-modified polypropylene, heating to 70°C and reacting for 11 hours, after the reaction is completed, filtering, washing, and drying to obtain modified polypropylene; wherein the mass ratio of o-vanillin, xylene, and surface-modified polypropylene is 0.1:135:30; Step (2) adding silane coupling agent KH-550 to a 95% by volume ethanol / water mixture, adjusting the pH of the mixture to 4 with acetic acid, and hydrolyzing at room temperature for 1 hour to obtain a silane coupling agent hydrolyzate; wherein the mass ratio of silane coupling agent KH-550 to the ethanol / water mixture is 5:95; adding 6.5g of nano-titanium dioxide to 425g of the above-mentioned silane coupling agent hydrolyzate, ultrasonically treating for 15min, and then reacting at 50°C for 90min. After the reaction is completed, filtering, and washing the obtained filter residue with ethanol and deionized water in turn, and drying at 80°C to obtain surface-modified nano-titanium dioxide; at room temperature, 2g of surface-modified nano-titanium dioxide and 3g of 4-amino-2,2,6,6-tetramethylpiperidine, 11g triethylamine, and 40g dichloromethane were mixed and ultrasonically treated for 45 minutes. Stirring was continued at 4°C, and then 45g of a 11.8% mass fraction of terephthaloyl chloride / dichloromethane mixture was added dropwise within 1.3 hours. The mixture was stirred and reacted at room temperature for 2 hours. After the reaction was completed, it was filtered and the obtained solid product was added to 30g of a 0.04g / L sodium hydroxide aqueous solution. Stirring was continued for 1 hour and centrifuged. The obtained precipitate was washed with deionized water and dried at 80°C to obtain modified nano-titanium dioxide. Step (3) The modified nano titanium dioxide, modified polypropylene and montmorillonite are mixed in a mass ratio of 5:100:3.5, melt-blended at 180° C. for 7 minutes, and extruded to obtain a polypropylene material for packaging bottles of silicone products.

[0023] Comparative Example 2 This comparative example discloses a method for preparing a polypropylene material for packaging bottles of organosilicon products, comprising the following steps: Step (1) adding silane coupling agent KH-550 to a 95% by volume ethanol / water mixture, adjusting the pH of the mixture to 4 with acetic acid, and hydrolyzing at room temperature for 1 hour to obtain a silane coupling agent hydrolyzate; wherein the mass ratio of silane coupling agent KH-550 to the ethanol / water mixture is 5:95; adding 6.5g of nano-titanium dioxide to 425g of the above-mentioned silane coupling agent hydrolyzate, ultrasonically treating for 15min, and then reacting at 50°C for 90min. After the reaction is completed, filtering, and washing the obtained filter residue with ethanol and deionized water in turn, and drying at 80°C to obtain surface-modified nano-titanium dioxide; at room temperature, 2g of surface-modified nano-titanium dioxide and 3g of 4-amino-2,2,6,6-tetramethylpiperidine, 11g triethylamine, and 40g dichloromethane were mixed and ultrasonically treated for 45 minutes. Stirring was continued at 4°C, and then 45g of a 11.8% mass fraction of terephthaloyl chloride / dichloromethane mixture was added dropwise within 1.3 hours. The mixture was stirred and reacted at room temperature for 2 hours. After the reaction was completed, it was filtered and the obtained solid product was added to 30g of a 0.04g / L sodium hydroxide aqueous solution. Stirring was continued for 1 hour and centrifuged. The obtained precipitate was washed with deionized water and dried at 80°C to obtain modified nano-titanium dioxide. Step (2) The modified nano-titanium dioxide, polypropylene particles and functionalized montmorillonite are mixed in a mass ratio of 5:100:3.5, melt-blended at 180° C. for 7 minutes, and extruded to obtain a polypropylene material for packaging bottles of silicone products.

[0024] Comparative Example 3 This comparative example discloses a method for preparing a polypropylene material for packaging bottles of organosilicon products, comprising the following steps: Step (1) mixing glycidyl methacrylate and ethylenediamine in equal molar ratios, adding them to methanol, stirring and reacting at room temperature for 24 hours, and after the reaction is completed, evaporating the solvent to obtain a modifier; adding the modifier and benzoyl peroxide to xylene in a nitrogen atmosphere, stirring for 30 minutes, then adding polypropylene particles, heating to 90°C and stirring and reacting for 6 hours, after the reaction is completed, purging with nitrogen, filtering, washing, and drying to obtain surface-modified polypropylene; wherein the mass ratio of the modifier, benzoyl peroxide, xylene, and polypropylene particles is 1.4:0.07:125:25; adding o-vanillin to xylene, stirring for 30 minutes, then adding surface-modified polypropylene, heating to 70°C and reacting for 11 hours, after the reaction is completed, filtering, washing, and drying to obtain modified polypropylene; wherein the mass ratio of o-vanillin, xylene, and surface-modified polypropylene is 0.1:135:30; Step (2) nano-titanium dioxide, modified polypropylene and functionalized montmorillonite are mixed in a mass ratio of 5:100:3.5, melt-blended at 180° C. for 7 minutes, and extruded to obtain a polypropylene material for packaging bottles of silicone products.

[0025] The functionalized montmorillonite used in the above Examples 2-4 and Comparative Examples 2-3 is the functionalized montmorillonite prepared in Example 1.

[0026] In the above embodiments and comparative examples, polypropylene particles, brand T30s, are from Dongguan Tongyi Plastic Raw Materials Co., Ltd.; nano titanium dioxide, model P25, with an average particle size of 20 nm, brand Perfemiker, product number PA87419, is from Shanghai Chuangsai Technology Co., Ltd.; montmorillonite, mesh number 3000, is from Lingshou County Ruixin Mineral Powder Factory.

[0027] Experimental example The polypropylene materials for the packaging bottles of the silicone products prepared in Examples 2-4 and Comparative Examples 1-3 were used as samples, recorded as Samples 1-3 and Comparative Samples 1-3, and performance tests were performed on each group of samples.

[0028] 1. Mechanical properties test: Each group of samples was made into a spline with a size of 80mm×10mm×4mm for mechanical properties test. The impact strength test was carried out on an XCJD pendulum impact testing machine with a notch depth of 20% of the spline thickness. Each sample was tested 5 times and the average value was taken. The tensile strength test was carried out on a BJDW universal testing machine with each sample tested 5 times and the average value was taken.

[0029] 2. Anti-aging performance test: Samples 1-3 and comparative samples 1-3 were made into strips with a size of 80mm×10mm×4mm and placed in a UV aging test chamber and a heat aging test chamber for 10 days of aging treatment. The UV aging test used a xenon lamp with a power of 35W, and the heat aging test was performed at a temperature of 50°C. After the treatment was completed, the samples were taken out and the tensile strength and impact strength of each group of samples after aging treatment were tested.

[0030] 3. Barrier performance test: Water vapor transmission rate was tested according to the standard GB / T26253-2010. The test equipment used was the Permatran-W3 / 61 water vapor permeability tester. Each group of samples was cut into a circular shape with a thickness of 30μm and a test area of ​​10cm. 2 , the test humidity is 90% and the temperature is 40℃.

[0031] The test results are shown in Table 1:

[0032] From the test results in Table 1, it can be seen that the polypropylene materials for silicone product packaging bottles prepared in Examples 2-4 of the present invention have excellent mechanical properties, anti-aging properties and barrier properties. From the comparison between Comparative Example 1 and Example 4, it can be seen that the functionalization treatment of montmorillonite increases the crosslinking density of the polypropylene system due to the presence of long alkyl chains and epoxy groups, improves the dispersibility of montmorillonite, and improves the comprehensive performance of the polypropylene material; from the comparison between Comparative Example 2 and Example 4, it can be seen that the polypropylene is modified to introduce amino functional groups and o-vanillin structures on the side chains of polypropylene. The amino functional groups can combine with the modified nano-titanium dioxide and functionalized montmorillonite through hydrogen bonding or chemical bonding, promote the dispersion of the modified nano-titanium dioxide and functionalized montmorillonite, and make the modified nano-titanium dioxide and functionalized montmorillonite play a better role, while the o-vanillin structure improves the performance of polypropylene. Anti-ultraviolet aging performance of the material; From the comparison between Comparative Example 3 and Example 4, it can be seen that the modified nano-titanium dioxide is used as a filler for polypropylene material, and the modified nano-titanium dioxide plays multiple roles: (1) as an inorganic filler to improve the mechanical strength and thermal oxidative aging resistance of the polypropylene material; (2) as a nucleating agent to improve crystallization and induce partial β-phase crystallization, thereby improving the strength, toughness, thermal stability and barrier properties of the polypropylene material; (3) synergistically with the hindered amine structure of 4-amino-2,2,6,6-tetramethylpiperidine to improve the anti-ultraviolet aging performance and thermal oxidative aging resistance of the polypropylene material; (4) filling the pores of the matrix, thereby further improving the barrier properties of the polypropylene material.

[0033] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing polypropylene material for packaging bottles of organosilicon products, characterized in that: The following steps are involved: Step (1) glycidyl methacrylate reacts with ethylenediamine to obtain a modifier; polypropylene reacts with the modifier and o-vanillin in sequence to obtain modified polypropylene; Step (2) nano-titanium dioxide reacts with a silane coupling agent KH-550 to obtain surface-modified nano-titanium dioxide; terephthaloyl chloride is used as a cross-linking agent to combine 4-amino-2,2,6,6-tetramethylpiperidine with the surface-modified nano-titanium dioxide to obtain modified nano-titanium dioxide; Step (3) The modified nano titanium dioxide, modified polypropylene and functionalized montmorillonite are mixed, melt-blended and extruded to obtain polypropylene material for packaging bottles of silicone products.

2. The method for preparing polypropylene material for packaging bottles of silicone products according to claim 1, characterized in that: In the step (1), during the preparation of the modifier, the conditions for the reaction of glycidyl methacrylate and ethylenediamine are as follows: glycidyl methacrylate and ethylenediamine are mixed in an equal molar ratio and stirred at room temperature for 22-26 hours.

3. The method for preparing polypropylene material for packaging bottles of organosilicon products according to claim 1, characterized in that: In the step (1), the preparation method of the modified polypropylene specifically comprises: adding a modifier and benzoyl peroxide to xylene in a nitrogen atmosphere, stirring for 20-40 minutes, then adding polypropylene particles, heating to 85-95°C and stirring for reaction for 5-7 hours, purifying to obtain surface-modified polypropylene; wherein the mass ratio of the modifier, benzoyl peroxide, xylene, and polypropylene particles is (1.1-1.7): (0.06-0.08): (100-150): (20-30); adding o-vanillin to xylene, stirring, then adding surface-modified polypropylene, heating to 60-80°C for reaction for 10-12 hours, purifying to obtain modified polypropylene; wherein the mass ratio of o-vanillin, xylene, and surface-modified polypropylene is (0.08-0.12): (120-150): (25-35).

4. The method for preparing polypropylene material for packaging bottles of organosilicon products according to claim 1, characterized in that: In the step (2), the preparation method of the surface-modified nano-titanium dioxide specifically comprises: mixing a silane coupling agent KH-550 and an ethanol / water mixture with a volume fraction of 95% in a mass ratio of (4-6):95, adjusting the pH of the mixed system to 3.5-4.5 with acetic acid, and hydrolyzing at room temperature for 1 hour to obtain a silane coupling agent hydrolyzate; mixing nano-titanium dioxide and the above-mentioned silane coupling agent hydrolyzate in a mass ratio of (5-8):(400-450), ultrasonicating, and then reacting at 48-52°C for 80-100 minutes, and purifying to obtain surface-modified nano-titanium dioxide.

5. The method for preparing polypropylene material for packaging bottles of organosilicon products according to claim 1, characterized in that: In the step (2), the preparation method of the modified nano-titanium dioxide specifically comprises: mixing surface-modified nano-titanium dioxide, 4-amino-2,2,6,6-tetramethylpiperidine, triethylamine, and dichloromethane at room temperature, ultrasonicating, and continuing to stir at 3-5°C, then dripping a terephthaloyl chloride / dichloromethane mixture with a mass fraction of 11.8%, and completing the dripping within 1-1.5 hours, stirring the mixed system at room temperature for 1.5-2.5 hours, and purifying to obtain modified nano-titanium dioxide; wherein the mass ratio of the surface-modified nano-titanium dioxide, 4-amino-2,2,6,6-tetramethylpiperidine, triethylamine, dichloromethane, and terephthaloyl chloride / dichloromethane mixture is (1-3): (2-4): (7.3-14.6): (30-50): (30-60).

6. The method for preparing polypropylene material for packaging bottles of organosilicon products according to claim 1, characterized in that: In the step (3), the mass ratio of the modified nano-titanium dioxide, modified polypropylene, and functionalized montmorillonite is (3-7):100:(2-5).

7. The method for preparing polypropylene material for packaging bottles of organosilicon products according to claim 1, characterized in that: In the step (3), the melt blending conditions are: melt blending at 170-190°C for 4-10 minutes.

8. The method for preparing polypropylene material for packaging bottles of organosilicon products according to claim 1, characterized in that: In the step (3), the preparation method of the functionalized montmorillonite is as follows: pretreated montmorillonite and 1,2-epoxy-9-decene are added to N,N-dimethylformamide, stirred, and then ammonium persulfate is added. The mixture is reacted at 55-70°C in a nitrogen atmosphere for 2-5 hours, and purified to obtain functionalized montmorillonite; wherein the mass ratio of N,N-dimethylformamide, pretreated montmorillonite, 1,2-epoxy-9-decene, and ammonium sulfate is (20-40):1:(0.3-0.5):(0.02-0.04).

9. The method for preparing polypropylene material for packaging bottles of organosilicon products according to claim 8, characterized in that: The preparation method of the pretreated montmorillonite comprises the following steps: mixing the montmorillonite with a 90% by volume ethanol / water mixture, ultrasonicating, adjusting the pH of the mixture to 3-4 with a 1 mol / L hydrochloric acid aqueous solution, adding a silane coupling agent KH-570, stirring and reacting at 70-75°C for 5-6 hours, and purifying to obtain the pretreated montmorillonite; wherein the mass ratio of the montmorillonite, the ethanol / water mixture, and the silane coupling agent KH-570 is 1:400:(0.02-0.05).

10. A polypropylene material for packaging bottles of organosilicon products prepared by the method for preparing a polypropylene material for packaging bottles of organosilicon products according to any one of claims 1 to 9.

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