High-strength anti-aging composite plastic and preparation process thereof

Abstract

The invention relates to the technical field of plastic preparation, and discloses a high-strength anti-aging composite plastic and a preparation technology thereof.The high-strength anti-aging composite plastic is prepared from, by weight, 100 parts of polypropylene, 10-20 parts of polyethylene, 5-10 parts of antioxidant modified titanium dioxide, 1-3 parts of zinc stearate, 2-5 parts of wax and 1-4 parts of calcium carbonate. The anti-oxidation modified titanium dioxide is prepared, the anti-aging performance, the flame retardant performance, the antibacterial performance and the mechanical performance of the composite plastic are improved through flame retardant elements, an antibacterial structure and an anti-aging structure contained in the anti-oxidation modified titanium dioxide, and the anti-oxidation modified titanium dioxide has wide application prospects in plastic products such as plastic storage cabinets and plastic trays.

Description

Technical Field

[0001] The invention relates to the technical field of plastic preparation, in particular to a high-strength anti-aging composite plastic and a preparation process thereof. Background Art

[0002] Polypropylene (PP) boasts excellent mechanical properties, heat resistance, and ease of processing and molding. It has been the most actively developed general-purpose synthetic resin in recent years and is widely used in the chemical, electrical, construction, and packaging industries. Polyethylene (PE) exhibits excellent mechanical and insulating properties and is widely used in various fields. However, both PE and PP exhibit poor aging resistance. Consequently, plastic products made from these materials, such as plastic storage cabinets and trays, can degrade or crosslink when exposed to factors such as light and oxygen, severely impacting the product's lifespan.

[0003] For example, Chinese patent application publication number CN 112225989 A discloses an anti-aging polypropylene plastic and a preparation method thereof. This invention uses polyethylene, polypropylene, an antioxidant, and the like as raw materials. The resulting plastic has good anti-aging properties and tensile properties, but does not improve the flame retardant and antibacterial properties of the plastic.

[0004] Therefore, the present invention provides a high-strength and anti-aging composite plastic and a preparation process thereof. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the deficiencies of the prior art, the present invention provides a high-strength anti-aging composite plastic and a preparation process thereof. The prepared composite plastic has excellent aging resistance, flame retardancy, antibacterial properties and mechanical properties.

[0007] (2) Technical solution

[0008] A high-strength and aging-resistant composite plastic, comprising the following raw materials in parts by weight: 100 parts by weight of polypropylene, 10-20 parts by weight of polyethylene, 5-10 parts by weight of antioxidant modified titanium dioxide, 1-3 parts by weight of zinc stearate, 2-5 parts by weight of wax, and 1-4 parts by weight of calcium carbonate;

[0009] The preparation process of the high-strength anti-aging composite plastic is as follows:

[0010] (1) adding an antioxidant modified gemini quaternary ammonium salt to an ethanol aqueous solution with a mass fraction of 80%, stirring and dispersing, adding titanium dioxide thereto, ultrasonically dispersing, heating to 70-75° C., reacting for 5-8 hours, filtering after the reaction, washing with ethanol, and drying to obtain antioxidant modified titanium dioxide. In this reaction, the silicon-oxygen structure contained in the antioxidant modified gemini quaternary ammonium salt is dehydrated and condensed with the hydroxyl group on the surface of nano-titanium dioxide, thereby reducing the agglomeration degree of nano-titanium dioxide and improving its dispersibility in organic matter;

[0011] (2) Polypropylene, polyethylene, antioxidant modified titanium dioxide, zinc stearate, wax, and calcium carbonate are added to a twin-screw extruder, extruded into granules, and injection molded to obtain a high-strength anti-aging composite plastic. Among them, on the one hand, nano-titanium dioxide is an inorganic photocatalytic antibacterial structure, which forms an organic-inorganic antibacterial structure with the organic quaternary ammonium salt antibacterial structure. On the other hand, the uniformly dispersed nano-titanium dioxide can absorb ultraviolet rays, prevent the generation of active free radicals, reduce the damage of ultraviolet light energy to the composite plastic, and form an anti-aging system with the main and auxiliary antioxidants, that is, nano-titanium dioxide absorbs ultraviolet light and reduces the generation of active free radicals, and the main and auxiliary antioxidants capture and decompose the generated active free radicals, thereby synergistically improving the anti-aging performance of the composite plastic.

[0012] Preferably, in (1), the dosage ratio of the antioxidant modified gemini quaternary ammonium salt and titanium dioxide is (0.02-0.05) mol:1 g.

[0013] Preferably, in (1), the preparation process of the antioxidant modified gemini quaternary ammonium salt is:

[0014] A1. Add 4-chloro-4'-hydroxybutylbenzophenone and triethylamine to a toluene solvent, control the temperature to -5 to 0°C, stir and mix evenly, then add a toluene solution of phenylphosphonium dichloride thereto, heat to 70-80°C, and keep the temperature to react for 3-5h. After the reaction is completed, cool, filter, distill under reduced pressure, and dry to obtain an intermediate product A, wherein the molar ratio of 4-chloro-4'-hydroxybutylbenzophenone, triethylamine, and phenylphosphonium dichloride is 2-2.4:2.2-2.5:1. In this step, triethylamine is used as a catalyst, phenylphosphonium dichloride, 4-chloro-4'-hydroxybutylbenzophenone, and triethylamine are used as catalysts. Ketone is used as the reaction raw material, and after substitution reaction, intermediate product A is obtained, that is, active group chlorine atom and phosphite structure are introduced into intermediate product A. The phosphite structure not only serves as a secondary antioxidant (this is because the phosphite structure can decompose peroxide free radicals and reduce the oxidation of peroxide free radicals to the material) to improve the anti-aging performance of the material, but also has flame retardant phosphorus element (phosphorus element decomposes under heat to produce phosphoric acid and metaphosphoric acid, strong dehydrating substances, which promote the dehydration of the material into carbon, forming a dense carbon layer, blocking the transportation of substances and energy) to improve the flame retardant effect of the material. The reaction route is:

[0015]

[0016] A2, intermediate product A, diethanolamine are added to absolute ethanol, stirred and dispersed, reflux reaction 40-48h, after completion of the reaction, cooled to room temperature, rotary evaporation to remove solvent, petroleum ether and water are added thereto for liquid separation, the aqueous phase is extracted with petroleum ether, the combined extracts are washed with deionized water, and distilled under reduced pressure to obtain intermediate product B, wherein the molar ratio of intermediate product A and diethanolamine is 1:6-8, and the molar ratio of intermediate product A and diethanolamine is 1:6-8. In this reaction, substitution reaction is generated between intermediate product A and diethanolamine to obtain intermediate product B, namely, substitution reaction is utilized to introduce active hydroxyl structure into intermediate product B. Its reaction scheme is:

[0017]

[0018] A3. Add the intermediate product B and triethylamine to a toluene solvent, stir and mix evenly, then add a toluene solution of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride thereto, stir and disperse, heat to 55-65° C., react for 12-16 hours, and after completion of the reaction, distill under reduced pressure, wash with deionized water, and dry to obtain an intermediate product C, wherein the molar ratio of the intermediate product B, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride, and triethylamine is 1:4.4-5:5-6. In this reaction, the hydroxyl group contained in the intermediate product B is subjected to an esterification reaction with β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride to obtain Intermediate product C, that is, a hindered phenol structure is introduced into intermediate product C. The phenolic hydroxyl groups in the hindered phenol structure can capture free radicals and interrupt the chain oxidation reaction. Moreover, since it contains four phenolic hydroxyl structures, the ability to provide hydrogen protons is increased, the ability to capture free radicals is enhanced, and the anti-oxidation and aging effect is increased. The hindered phenol structure is the main antioxidant, and the phosphite structure is the auxiliary antioxidant. That is, intermediate product C contains a main antioxidant structure and an auxiliary antioxidant structure. The hindered phenol structure captures and decomposes peroxide free radicals, and the auxiliary antioxidant structure decomposes peroxide free radicals. The two play a synergistic role, significantly improving the anti-aging performance of the composite plastic. The reaction route is:

[0019] in

[0020] A4, the intermediate product C, chloropropyltrimethoxysilane is added to the n-propanol solvent, stirred and mixed uniformly, and potassium iodide is added thereto, and under a nitrogen atmosphere, the reaction is stirred and refluxed for 15-20h. After the reaction is completed, distillation is performed, the deionized water washing is performed, and the drying is performed to obtain an antioxidant modified gemini quaternary ammonium salt, wherein the molar ratio of the intermediate product C and the chloropropyltrimethoxysilane is 1: 2-2.5, and the amount of potassium iodide is 1-1.5% of the total mass of the intermediate product C and the chloropropyltrimethoxysilane reactants. In this reaction process, potassium iodide is used as a catalyst, and a quaternization reaction occurs between the tertiary amine structure contained in the intermediate product C and the chloropropyltrimethoxysilane to obtain an antioxidant modified gemini quaternary ammonium salt, that is, the antioxidant modified gemini quaternary ammonium salt not only introduces an organic antibacterial gemini quaternary ammonium salt structure to enhance antibacterial properties, but also introduces a siloxane structure therein for the next reaction. The reaction scheme is:

[0021]

[0022] (3) Beneficial technical effects

[0023] The invention prepares an antioxidant modified gemini quaternary ammonium salt through a series of reactions. Firstly, the siloxane structure contained in the antioxidant modified gemini quaternary ammonium salt is used to perform organic modification on nano titanium dioxide. This is because nano titanium dioxide itself is easy to agglomerate and has poor compatibility with organic substances. The invention improves its compatibility with organic substances by performing organic modification on the nano titanium dioxide, and enables it to be uniformly dispersed in the organic substances. Secondly, the hindered phenol structure contained in the antioxidant modified gemini quaternary ammonium salt is used as the main antioxidant, and the phosphite structure is used as the auxiliary antioxidant to form an antioxidant with an intramolecular synergistic effect. The antioxidant capacity of the antioxidant with the intramolecular synergistic effect is better than that of the antioxidant with intermolecular synergistic effect. An antioxidant with a synergistic effect is added to the composite plastic to form a synergistic anti-aging system with evenly dispersed nano titanium dioxide, which can increase the anti-aging performance of the material; thirdly, the organic flame retardant elements (phosphorus and nitrogen) contained in the antioxidant modified gemini quaternary ammonium salt are used to form an organic-inorganic synergistic flame retardant structure with inorganic nano titanium dioxide and calcium carbonate; fourthly, the antioxidant modified gemini quaternary ammonium salt contains a gemini quaternary ammonium salt structure, which has an antibacterial effect better than the single quaternary ammonium salt structure, and titanium dioxide has photocatalytic antibacterial properties, which forms an organic-inorganic synergistic antibacterial structure with the gemini quaternary ammonium salt structure. When introduced into the composite plastic, it can synergistically improve the antibacterial performance of the material.

[0024] In addition, the antioxidant modified gemini quaternary ammonium salt prepared by the present invention contains a large number of branched structures, while polypropylene and polyethylene are both linear structures. When introduced into composite plastics, when subjected to external stress, the evenly dispersed nano-titanium dioxide can serve as a stress concentration point, and the branched structure can serve as a stress dispersion structure, which can effectively absorb the external stress and synergistically improve the mechanical properties of the composite material. DETAILED DESCRIPTION

[0025] Preparation process of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride: weigh 0.2 mol of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and add it to chloroform solvent, stir and dissolve, add 80 mL of dichlorothionyl under nitrogen protection, heat to 50°C, react at constant temperature for 6 hours, and distill under reduced pressure to obtain β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride.

[0026] Example 1

[0027] The preparation process of the antioxidant modified gemini quaternary ammonium salt in this embodiment is:

[0028] A1. Add 0.2 mol of 4-chloro-4'-hydroxybutyrophenone and 0.22 mol of triethylamine to a toluene solvent, control the temperature to -5°C, stir and mix evenly, then add a toluene solution containing 0.1 mol of phenylphosphonium dichloride, raise the temperature to 80°C, and keep the temperature to react for 3 hours. After the reaction is completed, cool, filter, distill under reduced pressure, and dry to obtain intermediate product A.

[0029] A2. Add 0.08 mol of intermediate product A and 0.48 mol of diethanolamine to anhydrous ethanol, stir and disperse, and reflux for 46 hours. After the reaction is completed, cool to room temperature, evaporate to remove the solvent, add petroleum ether and water to separate the liquids, extract the aqueous phase with petroleum ether, combine the extracts, wash with deionized water, and distill under reduced pressure to obtain intermediate product B.

[0030] A3. Add 0.06 mol of intermediate product B and 0.35 mol of triethylamine to toluene solvent, stir and mix evenly, then add 0.28 mol of toluene solution of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride, stir and disperse, heat to 55°C, react for 16 hours, and after the reaction is completed, distill under reduced pressure, wash with deionized water, and dry to obtain intermediate product C.

[0031] A4. Add 0.05 mol of intermediate product C and 0.1 mol of chloropropyltrimethoxysilane to n-propanol solvent, stir and mix evenly, then add 1% of potassium iodide of the total mass of the reactants, stir and reflux under nitrogen atmosphere for 20 hours. After the reaction, distill, wash with deionized water, and dry to obtain an antioxidant modified gemini quaternary ammonium salt.

[0032] The preparation process of a high-strength anti-aging composite plastic in this embodiment is as follows:

[0033] The preparation process of the high-strength anti-aging composite plastic is as follows:

[0034] (1) 0.02 mol of antioxidant modified gemini quaternary ammonium salt was added to an ethanol aqueous solution with a mass fraction of 80%, stirred and dispersed, 1 g of titanium dioxide was added thereto, ultrasonically dispersed, heated to 75 ° C, and reacted for 6 h. After the reaction was completed, filtered, washed with ethanol, and dried to obtain antioxidant modified titanium dioxide.

[0035] (2) 100 g of polypropylene, 10 g of polyethylene, 5 g of antioxidant modified titanium dioxide, 1 g of zinc stearate, 2 g of wax, and 1 g of calcium carbonate were added to a twin-screw extruder and extruded into granules. The temperatures of each zone of the extruder were 190°C, 195°C, 200°C, 205°C, 210°C, and 205°C, the head temperature was 200°C, and the speed was 200 r / min. The granules were injection molded in an injection molding machine. The temperatures of each zone of the injection molding machine were 210°C, 200°C, and 200°C to obtain a high-strength and anti-aging composite plastic.

[0036] Example 2

[0037] The preparation process of the antioxidant modified gemini quaternary ammonium salt in this embodiment is:

[0038] A1. Add 0.22 mol of 4-chloro-4'-hydroxybutyrophenone and 0.23 mol of triethylamine to a toluene solvent, control the temperature to 0°C, stir and mix evenly, then add a toluene solution containing 0.1 mol of phenylphosphonium dichloride, raise the temperature to 70°C, and keep the temperature to react for 4 hours. After the reaction is completed, cool, filter, distill under reduced pressure, and dry to obtain intermediate product A.

[0039] A2. Add 0.08 mol of intermediate product A and 0.6 mol of diethanolamine to anhydrous ethanol, stir and disperse, and reflux for 44 hours. After the reaction is completed, cool to room temperature, evaporate to remove the solvent, add petroleum ether and water to separate the liquids, extract the aqueous phase with petroleum ether, combine the extracts, wash with deionized water, and distill under reduced pressure to obtain intermediate product B.

[0040] A3. Add 0.06 mol of intermediate product B and 0.3 mol of triethylamine to toluene solvent, stir and mix evenly, then add 0.26 mol of toluene solution of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride, stir and disperse, heat to 65°C, react for 12 hours, and after the reaction is completed, distill under reduced pressure, wash with deionized water, and dry to obtain intermediate product C.

[0041] A4. Add 0.05 mol of intermediate product C and 0.12 mol of chloropropyltrimethoxysilane to n-propanol solvent, stir and mix evenly, then add 1.4% of potassium iodide of the total mass of the reactants, stir and reflux under nitrogen atmosphere for 15 hours. After the reaction is completed, distill, wash with deionized water, and dry to obtain an antioxidant modified gemini quaternary ammonium salt.

[0042] The preparation process of a high-strength anti-aging composite plastic in this embodiment is as follows:

[0043] The preparation process of the high-strength anti-aging composite plastic is as follows:

[0044] (1) 0.03 mol of antioxidant modified gemini quaternary ammonium salt was added to an ethanol aqueous solution with a mass fraction of 80%, stirred and dispersed, and then 1 g of titanium dioxide was added thereto, ultrasonically dispersed, heated to 75 ° C, and reacted for 5 h. After the reaction was completed, filtered, washed with ethanol, and dried to obtain antioxidant modified titanium dioxide.

[0045] (2) 100 g of polypropylene, 14 g of polyethylene, 6 g of antioxidant modified titanium dioxide, 3 g of zinc stearate, 5 g of wax, and 1 g of calcium carbonate were added to a twin-screw extruder and extruded into granules. The temperatures of each zone of the extruder were 190°C, 195°C, 200°C, 205°C, 210°C, and 205°C, the head temperature was 200°C, and the speed was 200 r / min. The granules were injection molded in an injection molding machine. The temperatures of each zone of the injection molding machine were 210°C, 200°C, and 200°C to obtain a high-strength and anti-aging composite plastic.

[0046] Example 3

[0047] The preparation process of the antioxidant modified gemini quaternary ammonium salt in this embodiment is:

[0048] A1. Add 0.23 mol of 4-chloro-4'-hydroxybutyrophenone and 0.24 mol of triethylamine to a toluene solvent, control the temperature to 0°C, stir and mix evenly, then add a toluene solution containing 0.1 mol of phenylphosphonium dichloride, raise the temperature to 75°C, and keep the temperature to react for 5 hours. After the reaction is completed, cool, filter, distill under reduced pressure, and dry to obtain intermediate product A.

[0049] A2. Add 0.08 mol of intermediate product A and 0.64 mol of diethanolamine to anhydrous ethanol, stir and disperse, and reflux for 40 hours. After the reaction is completed, cool to room temperature, evaporate to remove the solvent, add petroleum ether and water to separate the liquids, extract the aqueous phase with petroleum ether, combine the extracts, wash with deionized water, and distill under reduced pressure to obtain intermediate product B.

[0050] A3. Add 0.06 mol of intermediate product B and 0.36 mol of triethylamine to toluene solvent, stir and mix evenly, then add 0.3 mol of toluene solution of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride, stir and disperse, heat to 60°C, react for 14 hours, and after the reaction is completed, distill under reduced pressure, wash with deionized water, and dry to obtain intermediate product C.

[0051] A4. Add 0.05 mol of intermediate product C and 0.1 mol of chloropropyltrimethoxysilane to n-propanol solvent, stir and mix evenly, then add 1% of potassium iodide of the total mass of the reactants, stir and reflux under nitrogen atmosphere for 16 hours. After the reaction, distill, wash with deionized water, and dry to obtain an antioxidant modified gemini quaternary ammonium salt.

[0052] The preparation process of a high-strength anti-aging composite plastic in this embodiment is as follows:

[0053] The preparation process of the high-strength anti-aging composite plastic is as follows:

[0054] (1) 0.04 mol of antioxidant modified gemini quaternary ammonium salt was added to an ethanol aqueous solution with a mass fraction of 80%, stirred and dispersed, and then 1 g of titanium dioxide was added thereto, ultrasonically dispersed, heated to 70 ° C, and reacted for 8 h. After the reaction was completed, filtered, washed with ethanol, and dried to obtain antioxidant modified titanium dioxide.

[0055] (2) 100 g of polypropylene, 14 g of polyethylene, 8 g of antioxidant modified titanium dioxide, 2 g of zinc stearate, 4 g of wax, and 3 g of calcium carbonate were added to a twin-screw extruder and extruded into granules. The temperatures of each zone of the extruder were 190°C, 195°C, 200°C, 205°C, 210°C, and 205°C, the head temperature was 200°C, and the speed was 200 r / min. The granules were injection molded in an injection molding machine. The temperatures of each zone of the injection molding machine were 210°C, 200°C, and 200°C to obtain a high-strength and anti-aging composite plastic.

[0056] Example 4

[0057] The preparation process of the antioxidant modified gemini quaternary ammonium salt in this embodiment is:

[0058] A1. Add 0.24 mol of 4-chloro-4'-hydroxybutyrophenone and 0.25 mol of triethylamine to a toluene solvent, control the temperature to -5°C, stir and mix evenly, then add a toluene solution containing 0.1 mol of phenylphosphonium dichloride, raise the temperature to 80°C, and keep the temperature to react for 4 hours. After the reaction is completed, cool, filter, distill under reduced pressure, and dry to obtain intermediate product A.

[0059] A2. Add 0.08 mol of intermediate product A and 0.5 mol of diethanolamine to anhydrous ethanol, stir and disperse, and reflux for 48 hours. After the reaction is completed, cool to room temperature, evaporate to remove the solvent, add petroleum ether and water to separate the liquids, extract the aqueous phase with petroleum ether, combine the extracts, wash with deionized water, and distill under reduced pressure to obtain intermediate product B.

[0060] A3. Add 0.06 mol of intermediate product B and 0.34 ol of triethylamine to toluene solvent, stir and mix evenly, then add 0.27 ol of toluene solution of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride, stir and disperse, heat to 60°C, react for 16 hours, and after completion of the reaction, distill under reduced pressure, wash with deionized water, and dry to obtain intermediate product C.

[0061] A4. Add 0.05 mol of intermediate product C and 0.125 mol of chloropropyltrimethoxysilane to n-propanol solvent, stir and mix evenly, then add 1.5% of potassium iodide of the total mass of the reactants, stir and reflux under nitrogen atmosphere for 16 hours. After the reaction, distill, wash with deionized water, and dry to obtain an antioxidant modified gemini quaternary ammonium salt.

[0062] The preparation process of a high-strength anti-aging composite plastic in this embodiment is as follows:

[0063] The preparation process of the high-strength anti-aging composite plastic is as follows:

[0064] (1) 0.05 mol of antioxidant modified gemini quaternary ammonium salt was added to an ethanol aqueous solution with a mass fraction of 80%, stirred and dispersed, and then 1 g of titanium dioxide was added thereto, ultrasonically dispersed, heated to 70 ° C, and reacted for 8 h. After the reaction was completed, filtered, washed with ethanol, and dried to obtain antioxidant modified titanium dioxide.

[0065] (2) 100 g of polypropylene, 20 g of polyethylene, 10 g of antioxidant modified titanium dioxide, 3 g of zinc stearate, 3 g of wax, and 4 g of calcium carbonate were added to a twin-screw extruder and extruded into granules. The temperatures of each zone of the extruder were 190°C, 195°C, 200°C, 205°C, 210°C, and 205°C, the head temperature was 200°C, and the speed was 200 r / min. The granules were injection molded in an injection molding machine. The temperatures of each zone of the injection molding machine were 210°C, 200°C, and 200°C to obtain a high-strength and anti-aging composite plastic.

[0066] Comparative Example 1

[0067] The difference between this comparative example and Example 1 is that in step (2), nano titanium dioxide is used instead of antioxidant modified nano titanium dioxide.

[0068] The difference between this comparative example and Example 1 is that in step (2), antioxidant modified gemini quaternary ammonium salt is used instead of antioxidant modified nano titanium dioxide.

[0069] Accelerated aging test: The sample was subjected to UV accelerated aging test according to ASTM G154 Cycle 1, with a radiation wavelength of 240nm and a UV radiation intensity of 0.98W / m 2, continuous lighting is used and the blackboard temperature is 50℃.

[0070] Tensile performance test: refer to GB / T1040.1-2006 and conduct tensile test at a tensile rate of 20 mm / min.

[0071] Table 1:

[0072]

[0073] As can be seen from the above table, the tensile strength of Examples 1-4 is better than that of Comparative Examples 1-2. This is because the unmodified nano titanium dioxide in Comparative Example 1 is easily agglomerated, and therefore has poor compatibility in the composite plastic, and cannot effectively improve the mechanical properties of the composite plastic. As can be seen from Comparative Example 1 and Example 1, the modified nano titanium dioxide has good compatibility with organic materials and can effectively improve the strength of the material. Furthermore, the multi-branched structure contained in the antioxidant modified gemini quaternary ammonium salt and the uniformly dispersed nano titanium dioxide can effectively improve the mechanical properties of the material. As can be seen from Examples 1-4, with the increase in the amount of the antioxidant modified gemini quaternary ammonium salt, the strength increases.

[0074] After 2500 hours of aging, the composite plastic prepared by the present invention still has excellent tensile strength, and the anti-aging performance of Examples 1-4 is better than that of Comparative Examples 1-2. This is because Examples 1-4 contain main and auxiliary antioxidant structures and nano-titanium dioxide structures, which can effectively inhibit the generation of peroxides, reduce the degradation of materials by peroxides, and synergistically improve the anti-aging performance of the materials.

[0075] Flame retardant performance test: Use a horizontal and vertical burning tester to test the flame retardant performance of the material.

[0076] Antibacterial performance test: Refer to QB / T2591-2003 to test the antibacterial performance of the material, and the test bacteria is Escherichia coli.

[0077] Table 2:

[0078]

[0079]

[0080] As shown in Table 2, the flame retardant properties and antibacterial properties of Examples 1-4 are better than those of Comparative Examples 1-2, and the highest antibacterial rate can reach 99.9%.

[0081] In summary, the composite plastic prepared by the present invention has excellent anti-aging properties, flame retardancy, antibacterial properties and mechanical properties, and has broad application prospects in plastic products such as plastic storage cabinets, plastic trays, etc.

[0082] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and do not constitute a limitation of the present invention. Although the present invention has been illustrated in detail through the above embodiments, those skilled in the art may still make various changes in form and details based on the technical contents described in the Summary of the Invention and Examples without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A high-strength and anti-aging composite plastic, characterized in that: The high-strength and anti-aging composite plastic is composed of the following raw materials in parts by weight: 100 parts by weight of polypropylene, 10-20 parts of polyethylene, 5-10 parts of antioxidant modified titanium dioxide, 1-3 parts of zinc stearate, 2-5 parts of wax, and 1-4 parts of calcium carbonate; The preparation process of the high-strength anti-aging composite plastic is as follows: (1) adding the antioxidant modified gemini quaternary ammonium salt to an 80% by mass ethanol aqueous solution, stirring and dispersing, then adding titanium dioxide thereto, ultrasonically dispersing, heating to 70-75° C., reacting for 5-8 hours, and after the reaction is completed, filtering, washing with ethanol, and drying to obtain antioxidant modified titanium dioxide; (2) Polypropylene, polyethylene, antioxidant modified titanium dioxide, zinc stearate, wax, and calcium carbonate are added to a twin-screw extruder, extruded into granules, and injection molded to obtain a high-strength and anti-aging composite plastic.

2. The high-strength and anti-aging composite plastic according to claim 1, characterized in that: In the above (1), the dosage ratio of the antioxidant modified gemini quaternary ammonium salt and titanium dioxide is (0.02-0.05) mol:1 g.

3. The high-strength and anti-aging composite plastic according to claim 1, characterized in that: In (1), the preparation process of the antioxidant modified gemini quaternary ammonium salt is: A1. Add 4-chloro-4'-hydroxybutyrophenone and triethylamine to a toluene solvent, control the temperature to -5 to 0°C, stir and mix evenly, then add a toluene solution of phenylphosphonium dichloride, raise the temperature to 70-80°C, and keep the temperature to react for 3-5 hours. After the reaction is completed, cool, filter, distill under reduced pressure, and dry to obtain intermediate A. A2, adding intermediate product A and diethanolamine to anhydrous ethanol, stirring and dispersing, reflux reaction for 40-48h, cooling to room temperature after completion of the reaction, rotary evaporation to remove solvent, adding petroleum ether and water to separate the liquids, extracting the aqueous phase with petroleum ether, combining the extracts, washing with deionized water, and distilling under reduced pressure to obtain intermediate product B; A3. Add intermediate product B and triethylamine to toluene solvent, stir and mix evenly, then add a toluene solution of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride, stir and disperse, raise the temperature to 55-65°C, react for 12-16 hours, and after completion of the reaction, distill under reduced pressure, wash with deionized water, and dry to obtain intermediate product C; A4. Add the intermediate product C and chloropropyltrimethoxysilane to n-propanol solvent, stir and mix evenly, then add potassium iodide thereto, stir and reflux under nitrogen atmosphere for 15-20 hours. After the reaction is completed, distill, wash with deionized water, and dry to obtain an antioxidant modified gemini quaternary ammonium salt.

4. The high-strength and anti-aging composite plastic according to claim 3, characterized in that: In the above-mentioned A1, the molar ratio of 4-chloro-4'-hydroxybutylphenyl ketone, triethylamine and phenylphosphonium dichloride is 2-2.4:2.2-2.5:

1.

5. The high-strength and anti-aging composite plastic according to claim 3, characterized in that: In the A2, the molar ratio of the intermediate product A to diethanolamine is 1:6-8.

6. The high-strength and anti-aging composite plastic according to claim 3, characterized in that: In the above-mentioned A3, the molar ratio of the intermediate product B, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride and triethylamine is 1:4.4-5:5-6.

7. The high-strength and anti-aging composite plastic according to claim 3, characterized in that: In the above-mentioned A4, the molar ratio of the intermediate product C to chloropropyltrimethoxysilane is 1:2-2.

5.

8. The high-strength and anti-aging composite plastic according to claim 3, characterized in that: In the above-mentioned A4, the amount of potassium iodide used is 1-1.5% of the total mass of the reactants.

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