A carbon quantum dot-polyethylene propylene composite material and preparation method thereof

Abstract

The present invention provides a carbon quantum dot-polyethylene propylene composite material and a preparation method thereof, comprising the following components by mass: 30-100 parts of polypropylene resin, 10-70 parts of polyethylene resin, 1-5 parts of carbon quantum dots, 1-10 parts of modified glass fiber, and 0.1-5 parts of auxiliary agent; wherein the modified glass fiber is carbon quantum dots and fatty acid modified glass fiber. The carbon quantum dot-polyethylene propylene composite material provided by the present invention adopts polyethylene and polypropylene as matrix resins, and is compounded with modified glass fiber, carbon quantum dots and other components, which effectively improves the compatibility between different components, can form a more uniform and stable structure, and while giving the material optical, dielectric and other capabilities, improves the mechanical properties and stability of the product, and solves the problems existing in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a carbon quantum dot-polyethylene propylene composite material and a preparation method thereof. Background Art

[0002] Polyethylene and polypropylene are common organic polymer materials in modern society and are widely used in daily life. Polyethylene-polypropylene composite materials combine the two materials physically or chemically. The resulting product has the advantages of both materials, and has better mechanical properties such as tensile strength, flexural strength, impact strength, as well as better heat resistance, chemical corrosion resistance and processability, which can meet more different application requirements.

[0003] Carbon quantum dots are a new type of nanomaterial with excellent optical and photoelectric properties, high fluorescence quantum yield, variable fluorescence emission wavelength, and good thermal conductivity and electrical conductivity. Therefore, they can be used in many fields such as biological imaging, photoelectric detection, semiconductor screens, solar cells, etc.

[0004] Adding carbon quantum dots to an organic polymer matrix to prepare a composite material can give the material more abundant functions, and obtain products with functions such as thermal conductivity, electrical conductivity, and photoelectric effect. Existing technologies such as CN110484248A use polyethyleneimine-modified polyvinyl alcohol as a film-forming agent and mix it with carbon quantum dot functional particles to prepare a transparent film material that can emit fluorescence under ultraviolet light; CN115141430A adds a carbon quantum dot solution to polypropylene particles to obtain a carbon quantum dot / polypropylene masterbatch, and obtains a dielectric film material after melt granulation and other treatments, which has higher puncture resistance and energy storage effect.

[0005] However, the above technical solutions all directly mix carbon quantum dots with organic polymers. The compatibility between different materials is poor, which will cause the carbon quantum dots in the product to be unevenly dispersed and easily agglomerated, resulting in reduced mechanical properties of the composite material, and the optical, dielectric and other properties cannot reach the ideal level.

[0006] In summary, it is urgent to develop a new technical solution to solve the problems existing in the prior art. Summary of the invention

[0007] The carbon quantum dot-polyethylene propylene composite material provided by the present invention adopts polyethylene and polypropylene as matrix resins, and is compounded with modified glass fiber, carbon quantum dots and other ingredients, which effectively improves the compatibility between different components and can form a more uniform and stable structure. While giving the material optical, dielectric and other capabilities, it improves the mechanical properties and stability of the product, and solves the problems existing in the prior art.

[0008] One object of the present invention is to provide a carbon quantum dot-polyethylene propylene composite material, wherein the carbon quantum dot-polyethylene propylene composite material comprises the following components in parts by weight:

[0009]

[0010]

[0011] in,

[0012] The modified glass fiber is carbon quantum dots or fatty acid modified glass fiber.

[0013] Furthermore, the preparation method of the modified glass fiber comprises the following steps:

[0014] S1, mixing glass fiber and fatty acid, and performing ultrasonic heating reaction to obtain an intermediate product 1;

[0015] S2, mixing carbon quantum dots, alkenyl bromide and a catalyst, and heating the mixture for reaction to obtain an intermediate product 2;

[0016] S3, blending the intermediate product 1, the intermediate product 2 and an initiator, and heating them for reaction under the protection of an inert gas to obtain a modified glass fiber.

[0017] Furthermore, the fatty acid is selected from unsaturated fatty acids, and the carbon quantum dots are amino carbon quantum dots.

[0018] Furthermore, in step S1, the temperature of the ultrasonic heating reaction is 60-100°C and the time is 6-24h.

[0019] Furthermore, in step S2, the heating reaction is carried out at a temperature of 70-100°C and for a time of 2-10 hours.

[0020] Furthermore, in step S3, the heating reaction temperature is 60-90° C. and the time is 10-30 hours.

[0021] Furthermore, in step S3, the mass ratio of the intermediate product 1 to the intermediate product 2 is (1-10):1.

[0022] Furthermore, the auxiliary agent is selected from one or more of an initiator, a crosslinking agent, a light stabilizer, an antioxidant, a lubricant, a nucleating agent or a processing aid.

[0023] Another object of the present invention is to provide a method for preparing the above-mentioned carbon quantum dot-polyethylene propylene composite material, comprising the following steps:

[0024] The polypropylene resin, polyethylene resin, carbon quantum dots, modified glass fiber and additives are blended, melt-extruded and granulated to obtain the carbon quantum dots-polyethylene propylene composite material.

[0025] The present invention has the following beneficial effects:

[0026] The carbon quantum dot-polyethylene propylene composite material of the present invention adopts polyethylene and polypropylene as matrix resins, and is compounded with modified glass fiber and carbon quantum dots and other components to obtain a composite material. The modified glass fiber firstly reacts a glass fiber having a surface hydroxyl group with an unsaturated fatty acid to obtain an intermediate product 1 with a carbon-carbon double bond introduced on the surface, and at the same time reacts an amination carbon quantum dot with an alkenyl bromide to obtain a carbon quantum dot intermediate product 2 with a double bond introduced on the surface, and then the two are reacted to make the carbon quantum dots grafted on the surface of the glass fiber through chemical bonds, thereby making the surface of the modified glass fiber have groups such as double bonds, amino groups, ester groups and alkyl chains, effectively improving the compatibility between the glass fiber and the organic resin, and improving the dispersion effect of the glass fiber, wherein the double bonds can be further cross-linked with the resin, increasing the degree of bonding between the glass fiber and the resin, forming a more stable network structure, and enhancing the stability and strength of the composite material. In addition, the modified glass fiber has a larger specific surface area, and the carbon quantum dots introduced on its surface have a strong affinity for the carbon quantum dots in the composite material. Various active groups can also form intermolecular forces with the carbon quantum dots. Therefore, the modified glass fiber can also play the role of a compatibilizer, promoting the adsorption of carbon quantum dots and titanium dioxide additives on the surface of the modified glass fiber, avoiding the defects of component agglomeration and uneven dispersion, and making carbon quantum dots and other components more stably combined in the composite material. While ensuring mechanical properties, it gives the product better dielectric, thermal conductivity and optical properties, and has good application prospects. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0028] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0029] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0030] The polypropylene resin in the embodiment of the present invention is T30S; the polyethylene resin is high-density polyethylene 5502.

[0031] The carbon quantum dots in the embodiment of the present invention are homemade amination carbon quantum dots, and the preparation method comprises the following steps:

[0032] 2.1 g of citric acid monohydrate and 1.8 g of urea were added to 20 mL of water, and after ultrasonic treatment to dissolve, the mixture was heated at 160° C. for 4 h. After centrifugal filtration, cold ethanol was added for precipitation, and the amino carbon quantum dots were obtained after washing and drying.

[0033] The glass fiber in the embodiment of the present invention is F864783, purchased from Shanghai MacLean Biochemical Technology.

[0034] The auxiliary agent in the embodiment of the present invention is titanium dioxide and dicumyl peroxide in a mass ratio of 2:1.

[0035] The method for preparing the modified glass fiber in the embodiment of the present invention comprises the following steps:

[0036] S1, mixing glass fiber and linoleic acid in a mass ratio of 1:4, performing ultrasonic reaction at 70° C. for 12 h, filtering, washing and drying to obtain an intermediate product 1;

[0037] S2, using isopropanol and water in a volume ratio of 20:1 as solvent, carbon quantum dots and K 2 CO 3 , tetrabutylammonium bromide and allyl bromide were mixed and reacted at 80°C for 6 hours under nitrogen protection. The solvent was removed under reduced pressure, and then sufficient isopropanol was added to filter out the insoluble K 2 CO 3 Afterwards, the isopropanol was removed to obtain the intermediate product 2;

[0038] S3. Using water as solvent, the intermediate product 1, the intermediate product 2 and AIBN in a mass ratio of 4:1:0.05 are mixed, reacted at 75° C. for 24 hours under nitrogen protection, and the modified glass fiber is obtained after filtering and drying.

[0039] The "parts" in the embodiments of the present invention refer to parts by mass.

[0040] Example 1

[0041] A carbon quantum dot-polyethylene propylene composite material, the carbon quantum dot-polyethylene propylene composite material comprises the following components in parts by weight:

[0042]

[0043] The preparation method of the carbon quantum dot-polyethylene propylene composite material comprises the following steps:

[0044] According to the above mass fractions, polypropylene resin, polyethylene resin, carbon quantum dots, modified glass fiber and additives are blended, added into a twin-screw extruder, and melt-extruded and granulated at 200° C. to obtain the carbon quantum dots-polyethylene propylene composite material.

[0045] Example 2

[0046] A carbon quantum dot-polyethylene propylene composite material, the carbon quantum dot-polyethylene propylene composite material comprises the following components in parts by weight:

[0047]

[0048] The preparation method of the carbon quantum dot-polyethylene propylene composite material comprises the following steps:

[0049] According to the above mass fractions, polypropylene resin, polyethylene resin, carbon quantum dots, modified glass fiber and additives are blended, added into a twin-screw extruder, and melt-extruded and granulated at 200° C. to obtain the carbon quantum dots-polyethylene propylene composite material.

[0050] Example 3

[0051] A carbon quantum dot-polyethylene propylene composite material, the carbon quantum dot-polyethylene propylene composite material comprises the following components in parts by weight:

[0052]

[0053] The preparation method of the carbon quantum dot-polyethylene propylene composite material comprises the following steps:

[0054] According to the above mass fractions, polypropylene resin, polyethylene resin, carbon quantum dots, modified glass fiber and additives are blended, added into a twin-screw extruder, and melt-extruded and granulated at 200° C. to obtain the carbon quantum dots-polyethylene propylene composite material.

[0055] Comparative Example 1

[0056] A carbon quantum dot-polyethylene propylene composite material. The difference between this comparative example and Example 1 is that the modified glass fiber is replaced by a physical mixture of glass fiber and carbon quantum dots in a mass ratio of 4:1, and the amounts of other components and the preparation method are the same as those in Example 1.

[0057] Comparative Example 2

[0058] A carbon quantum dot-polyethylene propylene composite material. The difference between this comparative example and Example 1 is that the modified glass fiber is replaced by a physical mixture of glass fiber and intermediate product 2 in a mass ratio of 4:1, and the amounts of other components and the preparation method are the same as those in Example 1.

[0059] Test Case

[0060] Test method: The carbon quantum dot-polyethylene propylene composite material samples prepared in Examples 1-3 and Comparative Examples 1-2 were tested for performance according to standards such as GB / T 1040.1-2006 and GB / T 1843-2008. The results are shown in Table 1.

[0061] Table 1 Comparison of performance test results of Examples 1-3 and Comparative Examples 1-2

[0062]

[0063] According to the above test results, it can be seen that the carbon quantum dot-polyethylene propylene composite materials prepared in Examples 1-3 have good mechanical properties, excellent tensile strength, elongation at break and notched impact strength. In Comparative Example 1, the modified glass fiber is replaced by a mixture of unmodified glass fiber and carbon quantum dots, resulting in poor compatibility between glass fiber, carbon quantum dots and organic resin, insufficient dispersibility and stability, and the components cannot be cross-linked to form a network structure, and the mechanical strength is significantly reduced; Comparative Example 2 introduces double bonds on the surface of carbon quantum dots on the basis of Comparative Example 1, but it is still difficult to produce an ideal synergistic effect between the components, and it is impossible to obtain the adsorption and cross-linking structure between glass fiber, carbon quantum dots and resin, and the improvement of mechanical properties is not ideal. In summary, the carbon quantum dot-polyethylene propylene composite material of the present invention still has excellent strength after introducing components such as carbon quantum dots, glass fibers, titanium dioxide, etc., overcomes the deficiencies in the prior art, and has good application prospects in the fields of dielectrics, photoelectrics, photocatalysis, etc.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0065] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A carbon quantum dot-polyethylene propylene composite material, characterized in that: The carbon quantum dot-polyethylene propylene composite material comprises the following components in parts by weight: Polypropylene resin 30-100 parts Polyethylene resin 10-70 parts Carbon quantum dots 1-5 parts Modified glass fiber 1-10 parts Additives 0.1-5 parts; in, The modified glass fiber is carbon quantum dots or fatty acid modified glass fiber; The preparation method of the modified glass fiber comprises the following steps: S1, mixing glass fiber and fatty acid, and performing ultrasonic heating reaction to obtain an intermediate product 1; S2, mixing carbon quantum dots, alkenyl bromide and a catalyst, and heating the mixture for reaction to obtain an intermediate product 2; S3, mixing the intermediate product 1, the intermediate product 2 and an initiator, and heating them under the protection of an inert gas to react, to obtain a modified glass fiber; The fatty acid is selected from unsaturated fatty acids, and the carbon quantum dots are amino carbon quantum dots.

2. The carbon quantum dot-polyethylene propylene composite material according to claim 1, characterized in that: In step S1, the temperature of the ultrasonic heating reaction is 60-100°C and the time is 6-24 hours.

3. The carbon quantum dot-polyethylene propylene composite material according to claim 1, characterized in that: In step S2, the heating reaction is carried out at a temperature of 70-100°C and for a time of 2-10 h.

4. The carbon quantum dot-polyethylene propylene composite material according to claim 1, characterized in that: In step S3, the heating reaction temperature is 60-90° C. and the time is 10-30 h.

5. The carbon quantum dot-polyethylene propylene composite material according to claim 1, characterized in that: In step S3, the mass ratio of the intermediate product 1 to the intermediate product 2 is (1-10):

1.

6. The carbon quantum dot-polyethylene propylene composite material according to claim 1, characterized in that: The auxiliary agent is selected from one or more of an initiator, a crosslinking agent, a light stabilizer, an antioxidant, a lubricant, and a nucleating agent.

7. The method for preparing the carbon quantum dot-polyethylene propylene composite material according to any one of claims 1 to 6, characterized in that: The steps include: The polypropylene resin, polyethylene resin, carbon quantum dots, modified glass fiber and additives are blended, melt-extruded and granulated to obtain the carbon quantum dots-polyethylene propylene composite material.

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