A polymer composite material with magnetic properties and preparation method thereof

Abstract

The invention discloses a polymer composite material with magnetism and a preparation method thereof, and belongs to the field of polymer composite materials. The magnetic polymer composite material is prepared by weight from polypropylene, a compatibilizer, polystyrene, a toughening agent, an antioxidant, and a lubricant. The polystyrene is modified by magnetic nano-ferroferric oxide, and the modified magnetic polystyrene and polypropylene and an additive are melt-blended in a certain proportion to obtain a high-performance polymer composite material with magnetism. Due to the unique magnetic properties of the composite material, the application field of the material can be expanded, and it can be applied in magnetism-related fields such as electromagnetic shielding and microwave absorption.

Description

Technical Field

[0001] The invention relates to the field of polymer composite materials, and in particular to a polymer composite material with magnetism and a preparation method thereof. Background Art

[0002] Polypropylene is a commonly used polymer material. Due to its light weight, non-toxicity, odorlessness, good chemical stability and easy processing, people modify it to give it conductivity and optical properties, etc., and it can be widely used in the fields of electronic appliances, mechanical parts, office supplies and communication equipment. However, there are relatively few reports on the modification of polypropylene with magnetic particles, because nanoparticles have high surface energy, are easy to agglomerate, and are difficult to disperse evenly in polymer materials, which will also deteriorate the performance of the polymer. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present invention provides a polymer composite material with magnetism and a preparation method thereof.

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

[0005] A method for preparing a polymer composite material comprises the following steps:

[0006] The distilled water and sodium dodecyl sulfate are stirred and heated, and then potassium persulfate solution and styrene monomer with ferroferric oxide magnetic particles dispersed by ultrasound are added to obtain an emulsion;

[0007] The emulsion is coagulated, drained and dried to obtain magnetic polystyrene;

[0008] The polymer composite material is obtained by mixing polypropylene, magnetic polystyrene, a compatibilizer, a toughening agent, an antioxidant and a lubricant.

[0009] Optionally, the method for preparing the ferroferric oxide magnetic particles comprises the following steps: stirring an aqueous solution containing ferrous sulfate heptahydrate and ferric chloride, then adding ammonia water and oleic acid, continuing to stir the reaction, precipitating the solid components in the aqueous solution, and obtaining the ferroferric oxide magnetic particles after washing and drying.

[0010] A polymer composite material comprises the following raw materials in parts by weight:

[0011] Polypropylene 19.5~84.3 parts

[0012] Compatibilizer 2-8 parts

[0013] 10 to 50 parts of magnetic polystyrene.

[0014] Optionally, antioxidants, toughening agents and / or lubricants are also included.

[0015] Optionally, the compatibilizer is at least one of maleic anhydride grafted polypropylene, maleic anhydride grafted polystyrene, maleic anhydride grafted polyethylene, and methacrylic acid grafted polypropylene.

[0016] Optionally, the toughening agent is at least one of ethylene-octene copolymer, ethylene-butene copolymer, EPDM rubber / propylene-α-olefin copolymer, propylene-α-olefin copolymer, and styrene-ethylene-propylene-styrene block copolymer.

[0017] Optionally, the antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant, and a thioester antioxidant.

[0018] Optionally, the hindered phenol antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, the thioester is distearyl thiodipropionate or the phosphite is tris(2,4-di-tert-butylphenyl)phosphite.

[0019] Optionally, the lubricant is at least one of stearate, polyethylene wax, and ethylene bisstearamide.

[0020] Application of the above composite material in the preparation of electromagnetic shielding products or microwave absorbing products.

[0021] Beneficial effects of the present invention:

[0022] 1. After the ferrosoferric oxide nanoparticles are modified, they can be evenly dispersed in styrene, and further polymerization can obtain magnetic polystyrene materials, which overcomes the problem that ferrosoferric oxide magnetic nanoparticles are difficult to disperse in polymer materials.

[0023] 2. Blending magnetic polystyrene material and polypropylene material, and using maleic anhydride grafted polypropylene and maleic anhydride grafted polystyrene as compatibilizers can effectively improve the compatibility between the matrixes, so that the tensile strength, flexural strength and flexural modulus of the prepared magnetic polymer composite materials are improved to varying degrees, greatly expanding the application of the material in the magnetic field. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] 1. Preparation of magnetic ferroferric oxide nanoparticles: Add an aqueous solution of ferrous sulfate heptahydrate and ferric chloride to a certain amount of distilled water at 85°C under vigorous stirring, then add appropriate amounts of ammonia water and oleic acid, continue stirring and reacting for 5 hours, finally precipitate the black substance, wash it several times with deionized water and ethanol, and dry it for later use.

[0026] 2. Preparation of magnetic polystyrene: Add distilled water and sodium dodecyl sulfate to a three-necked flask equipped with a thermometer, a stirrer and a condenser, start stirring and heating. When the temperature reaches about 80°C, add potassium persulfate solution and styrene monomer with ultrasonically dispersed ferroferric oxide magnetic particles. Rapidly raise the temperature to 90°C and react for 1.5 hours. Finally, transfer the emulsion to a beaker, add sodium chloride to coagulate the emulsion, and finally use a Buchner funnel to drain the product and dry it for later use.

[0027] Embodiment 1:

[0028] A polymer composite material with magnetic properties, the formula of which is composed of the following raw materials in parts by weight:

[0029]

[0030]

[0031] The preparation method is as follows:

[0032] 1) mixing copolymerized polypropylene, magnetic polystyrene, a compatibilizer, a toughening agent, an antioxidant, and a lubricant according to a proportion in a high-speed mixer for 2 minutes to obtain a mixture;

[0033] 2) The mixture in (1) is fed into a twin-screw extruder through a main feed port, and a magnetic polymer composite material is obtained through melting, extrusion and granulation.

[0034] Embodiment 2:

[0035] A polymer composite material with magnetic properties, the formula of which is composed of the following raw materials in parts by weight:

[0036] The preparation method is the same as that of Example 1.

[0037] Embodiment three:

[0038] A polymer composite material with magnetic properties, the formula of which is composed of the following raw materials in parts by weight:

[0039] The preparation method is the same as that of Example 1.

[0040] Embodiment 4:

[0041] A polymer composite material with magnetic properties, the formula of which is composed of the following raw materials in parts by weight:

[0042]

[0043]

[0044] The preparation method is the same as that of Example 1.

[0045] Embodiment five:

[0046] A polymer composite material with magnetic properties, the formula of which is composed of the following raw materials in parts by weight:

[0047] The preparation method is the same as that of Example 1.

[0048] Comparative Example 1:

[0049] A polymer composite material, the formula of which is composed of the following raw materials in parts by weight:

[0050]

[0051]

[0052] The specific preparation method is as follows:

[0053] 1. Preparation of polystyrene:

[0054] Add distilled water and sodium dodecyl sulfate to a three-necked flask equipped with a thermometer, a stirrer and a condenser, start stirring and heating. When the temperature reaches about 80°C, add potassium persulfate solution and styrene monomer, quickly raise the temperature to 90°C and react for 1.5 hours. Finally, transfer the emulsion to a beaker, add sodium chloride to coagulate the emulsion, and finally use a Buchner funnel to drain the product and dry it for later use.

[0055] 2. Preparation of polymer composite materials:

[0056] 1) mixing copolymerized polypropylene, polystyrene, a compatibilizer, a toughening agent, an antioxidant, and a lubricant according to a ratio in a high-speed mixer for 2 minutes to obtain a mixture;

[0057] 2) The mixture in (1) is fed into a twin-screw extruder through a main feed port, and a polymer composite material is obtained through melting, extrusion and granulation.

[0058] Comparative Example 2:

[0059] A polymer composite material, the formula of which is composed of the following raw materials in parts by weight:

[0060]

[0061]

[0062] The specific preparation method is as follows:

[0063] 1. Preparation of magnetic ferroferric oxide nanoparticles: Add an aqueous solution of ferrous sulfate heptahydrate and ferric chloride to a certain amount of distilled water at 85°C under vigorous stirring, then add appropriate amounts of ammonia water and oleic acid, continue stirring and reacting for 5 hours, finally precipitate the black substance, wash it several times with deionized water and ethanol, and dry it for later use.

[0064] 2. Preparation of polystyrene: Add distilled water and sodium dodecyl sulfate to a three-necked flask equipped with a thermometer, a stirrer and a condenser, start stirring and heating. When the temperature reaches about 80°C, add potassium persulfate solution and styrene monomer, quickly raise the temperature to 90°C and react for 1.5 hours. Finally, transfer the emulsion to a beaker, add sodium chloride to coagulate the emulsion, and finally use a Buchner funnel to drain the product and dry it for later use.

[0065] 3. Preparation of polymer composites:

[0066] 1) mixing copolymerized polypropylene, polystyrene, ferrosoferric oxide, a compatibilizer, a toughening agent, an antioxidant, and a lubricant in a high-speed mixer according to a ratio for 2 minutes to obtain a mixture;

[0067] 2) The mixture in (1) is fed into a twin-screw extruder through a main feed port, and a polymer composite material is obtained through melting, extrusion and granulation.

[0068] The polymer composite materials prepared in the above Examples 1 to 5 and Comparative Examples 1 to 2 were tested for their density, tensile strength and other properties according to ISO standards, as shown in Table 1 below:

[0069] Table 1:

[0070]

[0071] From the performance results of each embodiment and comparative example in Table 1, it can be seen that:

[0072] 1. From Example 1 to Example 5, it can be seen that as the amount of magnetic polystyrene increases, the saturation magnetization of the polymer composite material gradually increases, and the residual magnetization and coercive force are very small, close to 0, indicating that the polymer composite material modified by nano-ferroferric oxide approximately presents superparamagnetism. Moreover, the addition of magnetic ferroferric oxide plays a certain reinforcing role on the composite material.

[0073] 2. It can be seen from Example 5 and Comparative Example 1 that the composite material obtained by blending and extruding polypropylene without being modified by ferrosoferric oxide has no magnetic properties.

[0074] 3. It can be seen from Example 5 and Comparative Example 2 that the polymer composite material obtained by adding magnetic ferroferric oxide and polystyrene alone to polypropylene for blending and extrusion has a very low saturation magnetization intensity, and the tensile strength, flexural modulus and notched impact strength of the material are also reduced, indicating that it is difficult to disperse the magnetic ferroferric oxide nanoparticles alone in the polymer matrix, resulting in relatively low magnetic properties and mechanical properties of the material.

[0075] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A method for preparing a polymer composite material, characterized in that: The following steps are involved: The distilled water and sodium dodecyl sulfate are stirred and heated, and then potassium persulfate solution and styrene monomer with ferroferric oxide magnetic particles dispersed by ultrasound are added to obtain an emulsion; The emulsion is coagulated, drained and dried to obtain magnetic polystyrene; The polymer composite material is obtained by mixing polypropylene, magnetic polystyrene, a compatibilizer, a toughening agent, an antioxidant and a lubricant.

2. The method for preparing a polymer composite material according to claim 1, characterized in that: The method for preparing the ferroferric oxide magnetic particles comprises the following steps: stirring an aqueous solution containing ferrous sulfate heptahydrate and ferric chloride, then adding ammonia water and oleic acid, continuing the stirring reaction, precipitating the solid components in the aqueous solution, washing and drying to obtain the ferroferric oxide magnetic particles.

3. A polymer composite material comprising the following raw materials in parts by weight: Polypropylene 19.5~84.3 parts Compatibilizer 2-8 parts 10-50 parts of magnetic polystyrene; The preparation method of the magnetic polystyrene comprises the following steps: The distilled water and sodium dodecyl sulfate are stirred and heated, and then potassium persulfate solution and styrene monomer with ferroferric oxide magnetic particles dispersed ultrasonically are added to obtain an emulsion; the emulsion is condensed, drained and dried to obtain magnetic polystyrene.

4. The polymer composite material according to claim 3, characterized in that Antioxidants, toughening agents and / or lubricants may also be included.

5. The polymer composite material according to claim 3, characterized in that The compatibilizer is at least one of maleic anhydride grafted polypropylene, maleic anhydride grafted polystyrene, maleic anhydride grafted polyethylene and methacrylic acid grafted polypropylene.

6. The polymer composite material according to claim 4, characterized in that The toughening agent is at least one of ethylene-octene copolymer, ethylene-butene copolymer, propylene-alpha olefin copolymer and styrene-ethylene-propylene-styrene block copolymer.

7. The polymer composite material according to claim 4, characterized in that The antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant and a thioester antioxidant.

8. The polymer composite material according to claim 7, characterized in that The hindered phenol antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, the thioester antioxidant is distearyl thiodipropionate or the phosphite antioxidant is tris(2,4-di-tert-butylphenyl) phosphite.

9. The polymer composite material according to claim 4, characterized in that The lubricant is at least one of stearate, polyethylene wax and ethylene bisstearamide.

10. Use of the composite material according to any one of claims 3 to 9 in the preparation of electromagnetic shielding products or microwave absorbing products.

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