Self-assembled SDS-LC-LDH (sodium dodecyl sulfate-liquid chromatography-layered double hydroxide) and preparation method thereof as well as modified polypropylene and preparation method thereof

Abstract

The invention provides a self-assembled SDS-LC-LDH and a preparation method thereof as well as modified polypropylene and a preparation method thereof, and particularly relates to the technical field of high polymer materials. The self-assembled SDS-LC-LDH comprises a layered double metal hydroxide, and lignin and catechin which are intercalated between the layers of the layered double metal hydroxide. According to the invention, lignin and catechin are inserted between layers of layered double hydroxides (LDH) to realize the dual functions of flame retardance and antibiosis. And under a high-temperature condition, bound water and carbon dioxide between LDH layers can be released to improve the flame retardant property. Meanwhile, metal hydroxides of the LDH laminates and lignin are subjected to catalytic reaction in the thermal degradation process, a compact carbonization layer is formed, and external heat and oxygen are effectively prevented from penetrating into the material. Phenolic hydroxyl groups in catechin can interfere with normal metabolism and growth of bacteria and show antibacterial characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a self-assembly type SDS-LC-LDH and a preparation method thereof, and modified polypropylene and a preparation method thereof. Background Art

[0002] The impeller is a key component in the range hood to achieve oil fume extraction. It generates negative pressure through rotation to extract oil fume from the kitchen. The material of the impeller is generally divided into two types: metal and plastic. Metal impellers are favored for their durability, although they may produce louder noise and are relatively expensive. In contrast, plastic impellers perform better in terms of noise control and cost. Common plastic materials include ABS (acrylonitrile-butadiene-styrene copolymer) and PP (polypropylene).

[0003] Considering the high temperature and open flames in the cooking environment, the plastic materials in the range hood need to meet the non-flammable or flame retardant standards. The impeller of PP material is usually flame-retardant modified by adding halogen or phosphorus flame retardants and manufactured by injection molding. However, there are some problems with this blended flame retardant modification method, such as the poor compatibility of flame retardants with plastic substrates, which may lead to large amounts of flame retardants, decreased mechanical properties of materials, and precipitation of flame retardants in high temperature and high humidity environments, which not only affects the appearance and flame retardant properties of the impeller, but may also cause harm to human health.

[0004] In addition, the impeller of the range hood is prone to breeding bacteria and mold in the environment of high humidity and heavy oil smoke for a long time, causing hygiene problems and health risks. Therefore, it is very important to improve the antibacterial properties of the impeller material, inhibit the growth of microorganisms, keep the impeller clean, reduce maintenance frequency, and extend the service life of the equipment.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] One of the purposes of the present invention is to provide a self-assembled SDS-LC-LDH to alleviate at least one of the above-mentioned technical problems in the prior art.

[0007] A second object of the present invention is to provide a method for preparing a self-assembled SDS-LC-LDH.

[0008] The third object of the present invention is to provide an application of a self-assembled SDS-LC-LDH.

[0009] A fourth object of the present invention is to provide a modified polypropylene.

[0010] A fifth object of the present invention is to provide a method for preparing modified polypropylene.

[0011] In order to solve the above-mentioned technical problems, the present invention particularly adopts the following technical solutions:

[0012] The first aspect of the present invention provides a self-assembled SDS-LC-LDH, comprising a layered double hydroxide, and lignin and catechin intercalated between layers of the layered double hydroxide;

[0013] The self-assembled SDS-LC-LDH has a hexagonal flake morphology;

[0014] The interlayer distance of the layered double hydroxide is greater than 2 nm.

[0015] Among them, SDS is the abbreviation of sodium dodecyl sulfate, LC is the abbreviation of lignin and catechin, and LDH is the abbreviation of layered double hydroxide.

[0016] Furthermore, in the self-assembled SDS-LC-LDH, the content of lignin is 0.5-8wt%; the content of catechin is 0.5-8wt%.

[0017] The second aspect of the present invention provides a method for preparing the self-assembled SDS-LC-LDH. First, a mixed solution of water, sodium dodecyl sulfate, lignin and catechin is prepared. Then, a divalent metal salt solution and a trivalent metal salt solution are added to the mixed solution for hydrothermal reaction to obtain the self-assembled SDS-LC-LDH.

[0018] Furthermore, the temperature of the hydrothermal reaction is 60-110° C., and the time is 10-24 hours.

[0019] Preferably, the pH of the hydrothermal reaction is 7-10.

[0020] Preferably, an alkaline solution is used to adjust the pH of the hydrothermal reaction.

[0021] Preferably, the alkali in the alkaline solution includes at least one of urea, ammonia water and sodium hydroxide.

[0022] Furthermore, in the preparation process of the self-assembled SDS-LC-LDH, the amount of sodium dodecyl sulfate added is 10 to 30 parts by weight; the amount of lignin added is 10 to 20 parts by weight; the amount of catechin added is 10 to 20 parts by weight; the amount of divalent metal salt added is 100 parts by weight; and the amount of trivalent metal salt added is 20 to 70 parts by weight.

[0023] Preferably, the divalent metal in the divalent metal salt comprises Cu 2+ 、Zn 2+ 、Ni 2+ and Mg 2+ At least one of .

[0024] Preferably, the trivalent metal in the trivalent metal salt includes Fe 3+ and / or Al 3+ .

[0025] Preferably, the anions in the divalent metal salt and the trivalent metal salt each independently include NO3 - 、SO4 2- and CO3 2- At least one of .

[0026] Preferably, the catechin includes at least one of catechin, epicatechin, gallocatechin and catechin gallate.

[0027] The third aspect of the present invention provides the use of the self-assembled SDS-LC-LDH as a flame retardant and antibacterial agent.

[0028] The fourth aspect of the present invention provides a modified polypropylene, which comprises, by weight, 70 to 95 parts of polypropylene, 0.3 to 4 parts of an antioxidant, 0.5 to 4 parts of a toughening agent, 3 to 8 parts of a compatibilizer, 10 to 20 parts of glass fiber, and 5 to 15 parts of a flame retardant and antibacterial agent;

[0029] Wherein, the flame retardant and antibacterial agent is the self-assembled SDS-LC-LDH described in the first aspect.

[0030] Further, the antioxidant includes at least one of tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, N,N'-1,6-hexylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid n-octadecanol, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)trione, triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] and 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

[0031] Preferably, the toughening agent includes at least one of ethylene-propylene copolymer, ethylene-hexene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, styrene-butadiene-styrene copolymer and hydrogenated styrene-butadiene-styrene copolymer.

[0032] Preferably, the compatibilizer includes at least one of EVA (ethylene-vinyl acetate copolymer), EPDM (ethylene-propylene-diene monomer copolymer) and SEBS (styrene-ethylene-butadiene-styrene copolymer).

[0033] The fifth aspect of the present invention provides a method for preparing the modified polypropylene, wherein all raw materials are mixed evenly in a high-speed mixer, and then the mixed materials are added to the main material port of an extruder for extrusion granulation to obtain the modified polypropylene.

[0034] Furthermore, the mixing time is 2 to 10 minutes.

[0035] Preferably, the rotation speed during the extrusion granulation process is 60 to 150 rpm.

[0036] Preferably, during the extrusion granulation process, the temperature of the feeding section is 195-205°C.

[0037] Preferably, during the extrusion granulation process, the temperatures of the three sections at the center of the screw are 205-215°C, 210-220°C and 200-210°C respectively.

[0038] Preferably, during the extrusion granulation process, the temperature of the die head is 180-200°C.

[0039] Preferably, the preparation method further includes a drying process of the raw materials before mixing.

[0040] Preferably, the drying is vacuum drying.

[0041] Preferably, the vacuum drying is carried out at 40 to 100° C. for 1 to 10 hours.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] The self-assembled SDS-LC-LDH provided by the present invention realizes the dual functions of flame retardancy and antibacterial by inserting lignin and catechin between the layers of layered double hydroxide (LDH). Under high temperature conditions, the bound water and carbon dioxide between the LDH layers can be released, diluting the surrounding oxygen and reducing the high temperature on the surface of the material, thereby improving the flame retardant performance. At the same time, the metal hydroxide of the LDH layer plate catalytically reacts with lignin during the thermal degradation process, prompting the formation of a dense carbonized layer on the surface of the material. This carbonized layer can effectively block external heat and oxygen from penetrating into the interior of the material, slowing down the mass loss rate of the material during the thermal degradation process. In addition, the phenolic hydroxyl groups in the lignin molecules form stable complexes with a variety of metal ions, further enhancing the flame retardant effect of the material. The phenolic hydroxyl groups in catechins can interfere with the normal metabolism and growth of bacteria, showing antibacterial properties. Therefore, the self-assembled SDS-LC-LDH realizes the dual functions of flame retardancy and antibacterial, and has important practical value.

[0044] The preparation method of the self-assembly SDS-LC-LDH provided by the present invention intercalates lignin and catechins in its layered structure during the formation of LDH, thereby realizing the self-assembly of the material. Meanwhile, the intercalation of lignin and catechins provides additional support and stability between LDH layers. The preparation method has a fine process flow, improves the consistency between batches, and is suitable for industrial large-scale production.

[0045] The application of the self-assembled SDS-LC-LDH provided by the present invention provides an additive with better performance for polymer materials in view of the advantages of the above-mentioned self-assembled SDS-LC-LDH, improves the performance of polymer materials, and is suitable for large-scale promotion and application.

[0046] The modified polypropylene provided by the present invention takes polypropylene material as a base material, introduces self-assembled SDS-LC-LDH as a flame retardant and antibacterial agent, improves the flame retardant properties of the polypropylene material, and at the same time gives the polypropylene antibacterial properties, expands the application scenarios of the polypropylene material, and has broad market potential and application value.

[0047] The preparation method of the modified polypropylene provided by the present invention ensures sufficient contact and dispersion between the components, and the internal structure of the modified polypropylene obtained is more uniform, and the distribution of the flame retardant and antibacterial agent is more refined, so that the modified polypropylene exhibits more excellent flame retardant and antibacterial properties in practical applications. At the same time, this method simplifies the production process, reduces energy consumption and production costs, and is conducive to large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 The SEM images obtained for characterization example 1;

[0050] Figure 2 This is the XRD pattern obtained for Characterization Example 2. DETAILED DESCRIPTION

[0051] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in combination with the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, but not all of the embodiments. The components of the embodiment of the present invention can be arranged and designed in various different configurations.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0053] The first aspect of the present invention provides a self-assembled SDS-LC-LDH, comprising a layered double hydroxide, and lignin and catechin intercalated between layers of the layered double hydroxide;

[0054] The self-assembled SDS-LC-LDH has a hexagonal flake morphology;

[0055] The interlayer distance of the layered double hydroxide is greater than 2 nm.

[0056] The self-assembled SDS-LC-LDH provided by the present invention realizes the dual functions of flame retardancy and antibacterial by inserting lignin and catechin between the layers of layered double hydroxide (LDH). Under high temperature conditions, the bound water and carbon dioxide between the LDH layers can be released, diluting the surrounding oxygen and reducing the high temperature on the surface of the material, thereby improving the flame retardant performance. At the same time, the metal hydroxide of the LDH layer plate catalytically reacts with lignin during the thermal degradation process, prompting the formation of a dense carbonized layer on the surface of the material. This carbonized layer can effectively block external heat and oxygen from penetrating into the interior of the material, slowing down the mass loss rate of the material during the thermal degradation process. In addition, the phenolic hydroxyl groups in the lignin molecules form stable complexes with a variety of metal ions, further enhancing the flame retardant effect of the material. The phenolic hydroxyl groups in catechins can interfere with the normal metabolism and growth of bacteria, showing antibacterial properties. Therefore, the self-assembled SDS-LC-LDH realizes the dual functions of flame retardancy and antibacterial, and has important practical value.

[0057] Among them, SDS is the abbreviation of sodium dodecyl sulfate, LC is the abbreviation of lignin and catechin, and LDH is the abbreviation of layered double hydroxide.

[0058] Specifically, layered double hydroxides are a typical type of anionic layered compounds, whose plate skeleton is composed of divalent and trivalent metal hydroxides. The plate layer is positively charged and has a large number of hydroxyl groups on the surface. The interlayer compensating anions and water molecules are combined with the main plate layer through hydrogen bonds, electrostatic forces and ionic bonds. The exchangeability of LDH interlayer anions not only enables the modifier to be organically combined with LDH, but also provides advantageous conditions for its composite with the lignin matrix. In addition, when the lignin / LDH composite material is subjected to high temperature, LDH releases interlayer bound water and CO2, which plays a role in diluting oxygen and reducing the surface temperature of lignin. In addition, the metal hydroxide of the LDH plate layer undergoes a special catalytic reaction with lignin during the combustion and degradation process, forming a dense carbon layer on the surface of the composite material, thereby effectively isolating the external heat and oxygen from penetrating into the interior of the polymer, and slowing down the mass loss rate of the material during thermal degradation. Therefore, LDH as a modifier can effectively improve the flame retardant properties of polypropylene materials. In addition, LDH-based modifiers provide more dispersion space for flame retardants due to their high specific surface area and adjustable interlayer spacing, which helps to improve the uniformity of the dispersion of flame retardants in the substrate and avoid the aggregation and sedimentation of flame retardants, thereby improving the overall stability and performance of the modified materials and solving the problem of easy precipitation of flame retardants.

[0059] Lignin has an aromatic ring and oxygen-containing functional group structure. It is a natural phenolic compound that is abundant in nature. It has high thermal stability and carbonization ability. It can easily form a stable carbon layer at high temperature, effectively isolate oxygen and heat, and improve the flame retardant properties of the material. In addition, the phenolic hydroxyl groups contained in lignin can form complexes with a variety of metal ions to enhance the flame retardant effect. Moreover, as a renewable resource, lignin has good biodegradability and is environmentally friendly. It can reduce the environmental pollution problems that may be caused by traditional flame retardants. It has a wide range of sources and low cost, which meets the requirements of sustainable development.

[0060] Catechins contain multiple phenolic hydroxyl groups, which can interact with proteins and enzymes on bacterial cell walls, interfering with the normal metabolism and growth of bacteria. In addition, catechins have strong antioxidant capacity, which can remove free radicals and reduce the damage of oxidative stress to cells, thereby reducing the pathogenicity of bacteria.

[0061] Taking advantage of the easy exchange of ions between LDH layers, lignin and catechins were intercalated between LDH layers to obtain self-assembled SDS-LC-LDH, which not only has flame retardant properties but also antibacterial properties.

[0062] SDS acts as a surfactant in the self-assembled SDS-LC-LDH material, which can form a stable intercalation structure between LDH layers, helping to improve the dispersibility and stability of LDH in water. The addition of SDS improves the LDH interlayer spacing and induces LDH nanosheets to form a porous flower-like structure. In addition, SDS increases the concentration of cationic counterions around the micelles by forming a synergistic micelle assembly during the synthesis process, resulting in enhanced growth of the LDH sheets along their lamellar surface, and because the surfactant has a longer molecular length, the LDH sheets are accumulated into nanoparticles. This self-assembly method provides new possibilities for the functionalization and application of LDH materials and enhances the flame retardant and antibacterial properties of the materials.

[0063] Furthermore, the content of lignin in the self-assembled SDS-LC-LDH is 0.5-8wt%; the content of catechin is 0.5-8wt%.

[0064] Typically but not limiting, in the self-assembled SDS-LC-LDH, the lignin content can be adjusted to 0.5wt%, 1wt%, 3wt%, 5wt%, 7wt% or 8wt%, or any value in the range of 0.5 to 8wt%; similarly, the catechin content can also be 0.5wt%, 1wt%, 3wt%, 5wt%, 7wt% or 8wt%, or any value in the range of 0.5 to 8wt%.

[0065] The second aspect of the present invention provides a method for preparing the self-assembled SDS-LC-LDH. First, a mixed solution of water, sodium dodecyl sulfate, lignin and catechin is prepared. Then, a divalent metal salt solution and a trivalent metal salt solution are added to the mixed solution for hydrothermal reaction to obtain the self-assembled SDS-LC-LDH.

[0066] The preparation method of the self-assembly SDS-LC-LDH provided by the present invention intercalates lignin and catechins in its layered structure during the formation of LDH, thereby realizing the self-assembly of the material. Meanwhile, the intercalation of lignin and catechins provides additional support and stability between LDH layers. The preparation method has a fine process flow, improves the consistency between batches, and is suitable for industrial large-scale production.

[0067] Furthermore, the temperature of the hydrothermal reaction is 60-110° C., and the time is 10-24 hours.

[0068] Typically but not limiting, the temperature of the hydrothermal reaction can be set at 60°C, 65°C, 70°C, 75°C, 80°C, 90°C, 100°C, 105°C or 110°C, or any temperature between 60°C and 110°C; the reaction time can be 10h, 12h, 14h, 16h, 18h, 20h, 22h or 24h, or any length of time between 10h and 24h.

[0069] Preferably, the pH of the hydrothermal reaction is 7 to 10 because under neutral or alkaline conditions, the structure of LDH consists of positively charged metal hydroxide layers and anions and water molecules between the layers. 2+ 、Al 3+ etc.) are more easily hydrolyzed to form metal hydroxide precipitation, which is the basis for the formation of LDH lamellae. Secondly, the alkaline environment is conducive to the polymerization of metal ions and the nucleation of LDH lamellae. Under alkaline conditions, OH - The concentration of ions is high, which helps to neutralize the positive charge of the metal hydroxide precipitate, thereby promoting the growth of lamellae and the formation of LDH structure.

[0070] Typically but not limiting, the pH of the hydrothermal reaction may be, for example, 7, 8, 9 or 10, or any value within the range of 7-10.

[0071] Preferably, an alkaline solution is used to adjust the pH of the hydrothermal reaction.

[0072] Preferably, the alkali in the alkaline solution includes at least one of urea, ammonia water and sodium hydroxide.

[0073] Furthermore, in the preparation process of the self-assembled SDS-LC-LDH, the amount of sodium dodecyl sulfate added is 10 to 30 parts by weight; the amount of lignin added is 10 to 20 parts by weight; the amount of catechin added is 10 to 20 parts by weight; the amount of divalent metal salt added is 100 parts by weight; and the amount of trivalent metal salt added is 20 to 70 parts by weight.

[0074] Typically but not limiting, the amount of sodium dodecyl sulfate can be typically but not limitingly 10 parts, 12 parts, 15 parts, 20 parts, 25 parts, 28 parts or 30 parts, or any value in the range of 10 to 30 parts; the amount of lignin can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts or 20 parts, or any amount in the range of 10 to 20 parts; the amount of catechin can also be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts or 20 parts, or any amount in the range of 10 to 20 parts. The amount of divalent metal salt is fixed at 100 parts, while the amount of trivalent metal salt can be 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 50 parts, 60 parts or 70 parts, or any value in the range of 20 to 70 parts.

[0075] Preferably, the divalent metal in the divalent metal salt comprises Cu 2+ 、Zn 2+ 、Ni 2+ and Mg 2+ At least one of .

[0076] Preferably, the trivalent metal in the trivalent metal salt includes Fe 3+ and / or Al 3+ .

[0077] Preferably, the anions in the divalent metal salt and the trivalent metal salt each independently include NO3 - 、SO4 2- and CO3 2- At least one of .

[0078] Preferably, the catechin includes at least one of catechin, epicatechin, gallocatechin and catechin gallate.

[0079] The third aspect of the present invention provides the use of the self-assembled SDS-LC-LDH as a flame retardant and antibacterial agent.

[0080] The application of the self-assembled SDS-LC-LDH provided by the present invention provides an additive with better performance for polymer materials in view of the advantages of the above-mentioned self-assembled SDS-LC-LDH, improves the performance of polymer materials, and is suitable for large-scale promotion and application.

[0081] The fourth aspect of the present invention provides a modified polypropylene, which comprises, by weight, 70 to 95 parts of polypropylene, 0.3 to 4 parts of an antioxidant, 0.5 to 4 parts of a toughening agent, 3 to 8 parts of a compatibilizer, 10 to 20 parts of glass fiber, and 5 to 15 parts of a flame retardant and antibacterial agent;

[0082] Wherein, the flame retardant and antibacterial agent is the self-assembled SDS-LC-LDH described in the first aspect.

[0083] The modified polypropylene provided by the present invention takes polypropylene material as a base material, introduces self-assembled SDS-LC-LDH as a flame retardant and antibacterial agent, improves the flame retardant properties of the polypropylene material, and at the same time gives the polypropylene antibacterial properties, expands the application scenarios of the polypropylene material, and has broad market potential and application value.

[0084] Typically but not limiting, the weight proportion of polypropylene can be 70 parts, 75 parts, 80 parts, 85 parts, 90 parts or 95 parts, the amount of antioxidant can be 0.3 parts, 0.6 parts, 1 parts, 2 parts, 3 parts or 4 parts, the amount of toughening agent can be 0.5 parts, 1 parts, 1.5 parts, 2 parts, 3 parts or 4 parts, the amount of compatibilizer can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts or 8 parts, the amount of glass fiber can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts or 20 parts, and the amount of flame retardant and antibacterial agent can be 5 parts, 6 parts, 7 parts, 8 parts, 10 parts, 12 parts, 13 parts or 15 parts.

[0085] Further, the antioxidant includes at least one of tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, N,N'-1,6-hexylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid n-octadecanol, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)trione, triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] and 2,2'-methylenebis(4-methyl-6-tert-butylphenol).

[0086] Preferably, the toughening agent includes at least one of ethylene-propylene copolymer, ethylene-hexene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, styrene-butadiene-styrene copolymer and hydrogenated styrene-butadiene-styrene copolymer.

[0087] Preferably, the compatibilizer includes at least one of EVA (ethylene-vinyl acetate copolymer), EPDM (ethylene-propylene-diene monomer copolymer) and SEBS (styrene-ethylene-butadiene-styrene copolymer).

[0088] The fifth aspect of the present invention provides a method for preparing the modified polypropylene, wherein all raw materials are mixed evenly in a high-speed mixer, and then the mixed materials are added to the main material port of an extruder for extrusion granulation to obtain the modified polypropylene.

[0089] The preparation method of the modified polypropylene provided by the present invention ensures sufficient contact and dispersion between the components, and the internal structure of the modified polypropylene obtained is more uniform, and the distribution of the flame retardant and antibacterial agent is more refined, so that the modified polypropylene exhibits more excellent flame retardant and antibacterial properties in practical applications. At the same time, this method simplifies the production process, reduces energy consumption and production costs, and is conducive to large-scale industrial production.

[0090] The modified polypropylene is produced in the form of granules, which facilitates the subsequent production of the impeller of the range hood by injection molding. These uniform granules not only help improve the feeding efficiency and reduce the waste of raw materials during the injection molding process, but also reduce the precipitation of flame retardants and antimicrobial agents, ensuring that each finished product has consistent performance and quality.

[0091] In addition to being used in range hood impellers, the modified polypropylene provided by the present invention can also be used in plastic material scenarios with flame retardancy requirements such as range hoods and stoves.

[0092] Furthermore, the mixing time is 2 to 10 minutes.

[0093] Typically but not limiting, the mixing process time can be 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, or any time within the range of 2 min to 10 min.

[0094] Preferably, the rotation speed during the extrusion granulation process is 60 to 150 rpm.

[0095] The rotation speed of the screw may preferably, but not limitedly, be 60 rpm, 65 rpm, 70 rpm, 75 rpm, 80 rpm, 90 rpm, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm or 150 rpm.

[0096] Preferably, during the extrusion granulation process, the temperature of the feeding section is 195-205°C.

[0097] Typically but not limiting, the temperature of the unloading section may be preferably 195°C, 196°C, 197°C, 198°C, 199°C, 200°C, 201°C, 202°C, 203°C, 204°C or 205°C.

[0098] Preferably, during the extrusion granulation process, the temperatures of the three sections at the center of the screw are 205-215°C, 210-220°C and 200-210°C respectively.

[0099] Preferably, during the extrusion granulation process, the temperature of the die head is 180-200°C.

[0100] Typically, but not limiting, during the extrusion pelletization process, the temperature of the die head may be, for example, 180°C, 182°C, 184°C, 186°C, 188°C, 190°C or 200°C.

[0101] Preferably, the preparation method further includes a drying process of the raw materials before mixing.

[0102] Preferably, the drying is vacuum drying.

[0103] Preferably, the vacuum drying is carried out at 40 to 100° C. for 1 to 10 hours.

[0104] Typically but not limiting, during the vacuum drying process, the temperature can be set at 40° C., 45° C., 50° C., 60° C., 70° C., 80° C., 90° C. or 100° C., or any temperature in the range of 40° C. to 100° C. The time can be controlled at 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h, or any time in the range of 1 h to 10 h.

[0105] In the following, some embodiments of the present invention are described in detail in conjunction with the embodiments. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0106] Example 1

[0107] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0108] 1. Add 100 g CuSO4, 20 g Al2(SO4)3, 10 g sodium dodecylbenzene sulfonate, 15 g lignin, 15 g catechin and 50 g urea to 5000 g distilled water.

[0109] 2. The hydrothermal reaction was carried out under continuous stirring at 60° C. and pH = 7 for 10 h. After the reaction, the product was filtered and washed with distilled water. Finally, the self-assembled SDS-LC-LDH was obtained after vacuum drying for 12 h.

[0110] Example 2

[0111] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0112] 1. Add 100 g CuSO4, 70 g Al2(SO4)3, 20 g sodium dodecylbenzene sulfonate, 15 g lignin, 15 g catechin and 50 g urea to 5000 g distilled water.

[0113] 2. Same as the step in Example 1.

[0114] Example 3

[0115] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0116] 1. Add 100 g CuSO4, 45 g Al2(SO4)3, 20 g sodium dodecylbenzene sulfonate, 15 g lignin, 15 g catechin and 50 g urea to 5000 g distilled water.

[0117] 2. Same as the step in Example 1.

[0118] Example 4

[0119] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0120] 1. Add 100 g of CuSO4, 20 g of Al2(SO4)3, 10 g of sodium dodecylbenzene sulfonate, 15 g of lignin, 5 g of catechins, and 50 g of urea to 5000 g of distilled water.

[0121] 2. Same as the step in Example 1.

[0122] Example 5

[0123] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0124] 1. Add 100 g CuSO4, 20 g Al2(SO4)3, 10 g sodium dodecylbenzene sulfonate, 5 g lignin, 15 g catechin and 50 g urea to 5000 g distilled water.

[0125] 2. Same as the step in Example 1.

[0126] Example 6

[0127] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0128] 1. Add 100 g of CuSO4, 20 g of Al2(SO4)3, 10 g of sodium dodecylbenzene sulfonate, 5 g of lignin, 5 g of catechins, and 50 g of urea to 5000 g of distilled water.

[0129] 2. Same as the step in Example 1.

[0130] Example 7

[0131] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0132] 1. Add 100 g ZnCl2, 20 g FeCl3, 10 g sodium dodecylbenzene sulfonate, 15 g lignin, 15 g catechins and 50 g urea to 5000 g distilled water.

[0133] 2. Same as the step in Example 1.

[0134] Example 8

[0135] This embodiment provides a self-assembled SDS-LC-LDH material, and the preparation method is as follows:

[0136] 1. Add 100 g MgCl2, 20 g FeCl3, 10 g sodium dodecylbenzene sulfonate, 15 g lignin, 15 g catechins, and 50 g urea to 5000 g distilled water.

[0137] 2. Same as the step in Example 1.

[0138] Comparative Example 1

[0139] This comparative example provides a SDS-LDH material, and the preparation method is as follows:

[0140] 1. Add 100 g of CuSO4, 20 g of Al2(SO4)3, 10 g of sodium dodecylbenzene sulfonate and 50 g of urea to 5000 g of distilled water.

[0141] 2. Same as the step in Example 1.

[0142] Comparative Example 2

[0143] This comparative example provides a SDS-C-LDH material, and the preparation method is as follows:

[0144] 1. Add 100 g CuSO4, 20 g Al2(SO4)3, 10 g sodium dodecylbenzene sulfonate, 15 g catechin and 50 g urea to 5000 g distilled water.

[0145] 2. Same as the step in Example 1.

[0146] Comparative Example 3

[0147] This comparative example provides a SDS-C-LDH material, and the preparation method is as follows:

[0148] 1. Add 100 g CuSO4, 20 g Al2(SO4)3, 10 g sodium dodecylbenzene sulfonate, 15 g lignin and 50 g urea to 5000 g distilled water.

[0149] 2. Same as the step in Example 1.

[0150] Embodiments 9 to 16

[0151] These embodiments provide modified polypropylene, the preparation method is as follows:

[0152] 1. Take polypropylene, the self-assembled SDS-LC-LDH material obtained in Examples 1 to 8, glass fiber, an antioxidant of pentaerythritol tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, a toughening agent of ethylene-propylene copolymer, and a compatibilizer of EVA, and vacuum dry them at 70°C for 3 hours.

[0153] 2. Add 72% polypropylene, 2% antioxidant, 2% toughening agent, 4% compatibilizer, 12% glass fiber and 8% modifier SDS-LC-LDH, mix in a high-speed mixer for 6 minutes, add the mixed materials from the main material port, extrude and granulate through an extruder, the speed of the screw extruder is 100 rpm, the temperature of the feeding section is 200°C, the temperatures of the three sections in the center of the screw are 210°C, 215°C and 205°C, the temperature of the die head is 190°C, and finally modified polypropylene is obtained.

[0154] Embodiment 17

[0155] This comparative example provides a modified polypropylene. The difference from Example 9 is that the raw materials are added according to 78% polypropylene, 2% antioxidant, 2% toughening agent, 4% compatibilizer, 12% glass fiber, and 2% modifier SDS-LC-LDH. The remaining raw materials and steps are the same as those in Example 9 and will not be repeated here.

[0156] Embodiment 18

[0157] This comparative example provides a modified polypropylene. The difference from Example 9 is that the raw materials are added according to 75% polypropylene, 2% antioxidant, 2% toughening agent, 4% compatibilizer, 12% glass fiber, and 5% modifier SDS-LC-LDH. The remaining raw materials and steps are the same as those in Example 9 and will not be repeated here.

[0158] Embodiment 19

[0159] This comparative example provides a modified polypropylene. The difference from Example 9 is that 65% polypropylene, 2% antioxidant, 2% toughening agent, 4% compatibilizer, 12% glass fiber, and 15% modifier SDS-LC-LDH are added. The remaining raw materials and steps are the same as those in Example 9 and will not be repeated here.

[0160] Embodiment 20

[0161] This comparative example provides a modified polypropylene. The difference from Example 9 is that 60% polypropylene, 2% antioxidant, 2% toughening agent, 4% compatibilizer, 12% glass fiber, and 20% modifier SDS-LC-LDH are added. The remaining raw materials and steps are the same as those in Example 9 and will not be repeated here.

[0162] Comparative Examples 4 to 6

[0163] This comparative example provides a modified polypropylene. The difference from Example 9 is that the materials obtained in Comparative Examples 1 to 3 are used to replace the self-assembled SDS-LC-LDH material. The remaining raw materials and steps are the same as those in Example 9 and will not be repeated here.

[0164] Comparative Example 7

[0165] This comparative example provides a modified polypropylene. The difference from Example 9 is that no self-assembled SDS-LC-LDH material is added. The remaining raw materials and steps are the same as those in Example 9 and will not be repeated here.

[0166] Characterization Example 1

[0167] The self-assembled SDS-LC-LDH material obtained in Example 1 was subjected to a scanning electron microscope, and the image obtained was as follows: Figure 1 shown.

[0168] from Figure 1 It can be seen that SDS-LC-LDH with hexagonal flake morphology was successfully synthesized via in situ assembly.

[0169] Characterization Example 2

[0170] The self-assembled SDS-LC-LDH material obtained in Example 1 was subjected to XRD, and the spectrum was as follows: Figure 2 shown.

[0171] analyze Figure 2 As a result, it was calculated from the characteristic peak at 2θ=3.38° in the X-ray diffraction pattern of SDS-LC-LDH that the interlayer spacing of the modified SDS-LC-LDH was increased to 2.553nm, allowing the polypropylene chain segments to smoothly enter the LDH interlayer, greatly improving the dispersibility of SDS-LC-LDH in the polypropylene matrix, thereby effectively improving the flame retardant and UV resistance of the material.

[0172] Test example

[0173] The modified polypropylene obtained in Examples 9 to 20 and Comparative Examples 4 to 7 was subjected to performance tests, including:

[0174] Limiting Oxygen Index (LOI): Tested according to the provisions of GB / 8624-2012, that is, under specified conditions, the minimum oxygen concentration for the sample to maintain balanced combustion in a nitrogen and oxygen mixture.

[0175] Vertical burning performance: Tested according to the provisions of “Flame retardant performance test method-vertical burning method” (GB2409-84).

[0176] Antibacterial properties: Tested in accordance with the provisions of GB 21551.2-2010, including the antibacterial rate of the material against Escherichia coli and Staphylococcus aureus.

[0177] Tensile strength: Tested in accordance with GB / T1040.

[0178] The obtained data are shown in Table 1 below.

[0179] Table 1

[0180]

[0181]

[0182] As can be seen from Table 1, compared with Example 9, the flame retardant properties of the modified polypropylene provided in Comparative Example 4 are slightly reduced, and the antibacterial effect disappears, but the mechanical properties of the material will be improved. Comparative Example 5 or Comparative Example 6 uses lignin or catechin alone to intercalate and modify LDH, and the flame retardant properties and antibacterial properties of the material will be affected respectively. Example 20 uses an excess of SDS-LC-LDH modifier to reduce the mechanical properties of the material. Compared with the polypropylene material of Comparative Example 7, the mechanical properties of the polypropylene material containing SDS-LC-LDH modifier in Example 1 are reduced, but the flame retardant properties and antibacterial properties are significantly improved.

[0183] In Examples 10 and 11, the SDS content is increased, the LDH interlayer distance is relatively increased, the polypropylene molecular chain intercalation is easier, the compatibility of the modifier and the substrate is higher, and the material strength is improved.

[0184] Example 12: The catechin content is reduced, and the antibacterial property of the material decreases.

[0185] Example 13 reduces the lignin content and the flame retardant properties of the material are reduced.

[0186] In Example 14, it was found that the catechin and wood contents in SDS-LC-LDH were reduced, the antibacterial performance of the material decreased, the material had a certain flame retardant effect, but the vertical burning performance was reduced.

[0187] Example 17 found that when the SDS-LC-LDH content was too low, the flame retardancy and antibacterial properties of the material were low, but the mechanical properties of the material were improved.

[0188] Examples 18 and 19 show that SDS-LC-LDH has good flame retardancy, antibacterial properties and mechanical properties within the preferred range.

[0189] Example 20: The SDS-LC-LDH content is too high and the mechanical properties of the material are reduced.

[0190] Comparative Examples 4, 5, and 6 show that the SDS-LDH not modified with catechin and lignin has no significant effect on improving the flame retardant and antibacterial properties of the material.

[0191] Comparative Example 7 found that without using SDS-LC-LDH, the flame retardancy and antibacterial properties of the material were poor, but the mechanical properties were good.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Self-assembled SDS-LC-LDH, characterized in that It includes a layered double metal hydroxide, and lignin and catechin intercalated between layers of the layered double metal hydroxide; The self-assembled SDS-LC-LDH has a hexagonal flake morphology; The interlayer distance of the layered double hydroxide is greater than 2 nm.

2. The self-assembled SDS-LC-LDH according to claim 1, characterized in that The content of lignin is 0.5-8wt%; the content of catechin is 0.5-8wt%.

3. A method for preparing the self-assembled SDS-LC-LDH according to claim 1 or 2, characterized in that: Firstly, a mixed solution of water, sodium dodecyl sulfate, lignin and catechin is prepared, and then a divalent metal salt solution and a trivalent metal salt solution are added to the mixed solution for hydrothermal reaction to obtain the self-assembled SDS-LC-LDH.

4. The preparation method according to claim 3, characterized in that: The temperature of the hydrothermal reaction is 60-110°C and the time is 10-24h; Preferably, the pH of the hydrothermal reaction is 7 to 10; Preferably, an alkaline solution is used to adjust the pH of the hydrothermal reaction; Preferably, the alkali in the alkaline solution includes at least one of urea, ammonia water and sodium hydroxide.

5. The preparation method according to claim 3, characterized in that: According to weight percentage, the amount of sodium dodecyl sulfate is 10-30 parts; the amount of lignin is 10-20 parts; the amount of catechin is 10-20 parts; the amount of divalent metal salt is 100 parts; the amount of trivalent metal salt is 20-70 parts; Preferably, the divalent metal in the divalent metal salt comprises Cu 2+ 、Zn 2+ 、Ni 2+ and Mg 2+ At least one of; Preferably, the trivalent metal in the trivalent metal salt includes Fe 3+ and / or Al 3+ ; Preferably, the anions in the divalent metal salt and the trivalent metal salt each independently include NO3 - 、SO4 2- and CO3 2- At least one of; Preferably, the catechin includes at least one of catechin, epicatechin, gallocatechin and catechin gallate.

6. Use of the self-assembled SDS-LC-LDH according to claim 1 or 2 as a flame retardant antibacterial agent.

7. A modified polypropylene, characterized in that: According to weight parts, it includes 70-95 parts of polypropylene, 0.3-4 parts of antioxidant, 0.5-4 parts of toughening agent, 3-8 parts of compatibilizer, 10-20 parts of glass fiber and 5-15 parts of flame retardant and antibacterial agent; Wherein, the flame retardant antibacterial agent is the self-assembled SDS-LC-LDH described in claim 1 or 2.

8. The modified polypropylene according to claim 7, characterized in that The antioxidant comprises at least one of tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, N,N'-1,6-hexylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid n-octadecanol, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)trione, triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] and 2,2'-methylenebis(4-methyl-6-tert-butylphenol); Preferably, the toughening agent comprises at least one of ethylene-propylene copolymer, ethylene-hexene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, styrene-butadiene-styrene copolymer and hydrogenated styrene-butadiene-styrene copolymer; Preferably, the compatibilizer includes at least one of EVA, EPDM and SEBS.

9. A method for preparing modified polypropylene according to claim 7 or 8, characterized in that: All raw materials are mixed evenly in a high-speed mixer, and then the mixed materials are added to the main material port of the extruder for extrusion granulation to obtain the modified polypropylene.

10. The preparation method according to claim 9, characterized in that: The mixing time is 2 to 10 minutes; Preferably, the rotation speed during extrusion granulation is 60 to 150 rpm; Preferably, during the extrusion granulation process, the temperature of the feeding section is 195-205°C; Preferably, during the extrusion granulation process, the temperatures of the three sections at the center of the screw are 205-215°C, 210-220°C and 200-210°C respectively; Preferably, during the extrusion granulation process, the temperature of the die head is 180 to 200°C; Preferably, the preparation method further comprises a drying process of the raw materials before mixing; Preferably, the drying is vacuum drying; Preferably, the vacuum drying is carried out at 40 to 100° C. for 1 to 10 hours.

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