Graphene modified PP resin antibacterial master batch and preparation method thereof

Abstract

The invention discloses a graphene modified PP (polypropylene) resin antibacterial master batch and a preparation method thereof. The graphene modified PP resin antibacterial master batch is prepared from the following components in parts by weight: 100 to 150 parts of polypropylene, 100 to 150 parts of nano calcium carbonate, 2 to 10 parts of graphene, 0.01 to 0.1 part of sodium pyrithione, 0.003 to 0.01 part of calcium stearate, 1 to 5 parts of maleic anhydride grafted polypropylene, 0.03 to 0.08 part of coupling agent and 0.1 to 0.8 part of antioxidant. The preparation method comprises the following steps: adding graphene into an ethanol solution, adding a coupling agent at the same time for ultrasonic dispersion, and then removing ethanol in a rotary evaporation manner; sodium pyrithione and calcium stearate are stirred and mixed uniformly, so that the surface of sodium pyrithione is coated with calcium stearate; and uniformly mixing and stirring nano calcium carbonate, maleic anhydride grafted polypropylene, an antioxidant, the pretreated graphene, sodium pyrithione and polypropylene.

Description

Technical Field

[0001] The invention relates to the technical field of PP resin industrial masterbatch, and in particular to a graphene-modified PP resin antibacterial masterbatch and a preparation method thereof. Background Art

[0002] Polypropylene (PP) resin is widely used in many fields, such as packaging, automotive interiors, medical devices, etc., due to its good comprehensive properties, such as low density, high strength and heat resistance. However, PP resin itself does not have antibacterial properties. In some application scenarios with high hygiene requirements, it is easy to breed bacteria, thus affecting the safety and service life of the product.

[0003] In order to give PP resin antibacterial properties, the traditional method is usually to add antibacterial agents. Common antibacterial agents include organic antibacterial agents (such as quaternary ammonium salts, halamines, etc.) and inorganic antibacterial agents (such as silver ions, zinc oxide, etc.). Although organic antibacterial agents have certain antibacterial effects, they have problems such as poor heat resistance, limited antibacterial durability, and potential harm to the environment and human health.

[0004] As a new type of nanomaterial, graphene has unique two-dimensional structure, excellent mechanical properties, high conductivity and good thermal stability. In recent years, studies have found that graphene and its derivatives have antibacterial activity against a variety of bacteria, and its antibacterial mechanism mainly includes physical cutting and induced oxidative stress. Therefore, applying graphene to the modification of PP resin is expected to develop materials with high-efficiency antibacterial properties. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a graphene-modified PP resin antibacterial masterbatch and a preparation method thereof, so as to solve the problem in the prior art of how to make the PP resin industrial masterbatch have antibacterial properties when using PP resin industrial masterbatch for production.

[0006] The present invention firstly provides a graphene-modified PP resin antibacterial masterbatch, which comprises the following components in parts by weight: 100-150 parts of polypropylene, 100-150 parts of nano calcium carbonate, 2-10 parts of graphene, 0.01-0.1 parts of sodium pyrithione, 0.003-0.01 parts of calcium stearate, 1-5 parts of maleic anhydride grafted polypropylene, 0.03-0.08 parts of coupling agent and 0.1-0.8 parts of antioxidant.

[0007] Preferably, the antioxidant is selected from hindered phenol antioxidants and phosphite antioxidants.

[0008] Preferably, the coupling agent is selected from γ-aminopropyltriethoxysilane.

[0009] The present invention also provides a method for preparing the above-mentioned graphene-modified PP resin antibacterial masterbatch, the preparation method comprising:

[0010] S10, adding graphene to an ethanol solution, and adding a coupling agent for ultrasonic dispersion, so that the coupling agent is fully coated on the surface of the graphene, and then removing the ethanol by rotary evaporation to obtain pretreated graphene;

[0011] S20, stirring and mixing sodium pyrithione and calcium stearate evenly, so that the calcium stearate is coated on the surface of sodium pyrithione to obtain pretreated sodium pyrithione;

[0012] S30, mixing and stirring the nano calcium carbonate, maleic anhydride grafted polypropylene, antioxidant, pretreated graphene, pretreated sodium pyrithione and polypropylene to prepare graphene-modified PP resin antibacterial masterbatch.

[0013] Preferably, the ethanol solution in step S10 uses an ethanol solution with a volume fraction of 70% to 80%.

[0014] Preferably, the mixing and stirring in step S30 includes: firstly stirring the nano-calcium carbonate, maleic anhydride grafted polypropylene, antioxidant, pretreated graphene, pretreated sodium pyrithione and polypropylene at room temperature to obtain a mixture, and then heating and stirring the mixture at a high temperature, wherein the temperature of the warm heating and stirring is 180°C to 220°C.

[0015] Preferably, in step S30, the mass ratio of nano-calcium carbonate to polypropylene is 1:1.

[0016] Preferably, in step S30, the mass fraction of maleic anhydride grafted polypropylene is 1% to 3% of polypropylene; the mass fraction of antioxidant is 0.1% to 0.5% of polypropylene; the mass fraction of graphene is 1% to 5% of polypropylene; and the mass fraction of sodium pyrithione is 1% to 5% of graphene.

[0017] Preferably, the mass fraction of the coupling agent in step S10 is 1% to 5% of the graphene.

[0018] Preferably, the mass fraction of calcium stearate in step S20 is 5% to 20% of sodium pyrithione.

[0019] In the graphene-modified PP resin antibacterial masterbatch and the preparation method thereof provided by the present invention, the antibacterial effect of sodium pyrithione is combined with the bactericidal action mechanism of the physical cutting action of graphene, and calcium stearate is added to pretreat the sodium pyrithione, a coupling agent is used to pretreat the graphene, and maleic anhydride is used to graft polypropylene to enhance the compatibility of graphene and graphene, nano calcium carbonate can make graphene and sodium pyrithione better dispersed in the PP resin matrix and make the PP resin have good mechanical properties, and the antioxidant can maintain the stability of the mechanical properties of the PP resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the preparation process of the graphene-modified PP resin antibacterial masterbatch provided by the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0022] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "top", "bottom", "top surface", "bottom surface", "inside", "outside", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0023] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If the terms "first", "second", "third" are described, they are only used for the purpose of description and distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following is an explanation of the embodiments of the present invention based on its overall structure.

[0025] A graphene-modified PP resin antibacterial masterbatch comprises the following components in parts by weight: 100-150 parts of polypropylene, 100-150 parts of nano-calcium carbonate, 2-10 parts of graphene, 0.01-0.1 parts of sodium pyrithione, 0.003-0.01 parts of calcium stearate, 1-5 parts of maleic anhydride grafted polypropylene, 0.03-0.08 parts of coupling agent, and 0.1-0.8 parts of antioxidant.

[0026] In a preferred embodiment, the antioxidant is selected from hindered phenol antioxidants and phosphite antioxidants, wherein, as an optional embodiment, hindered phenol antioxidants can be used alone or phosphite antioxidants can be used alone. As a preferred embodiment, hindered phenol antioxidants and phosphite antioxidants are used together to exert a synergistic effect and play an antioxidant and protective role on PP resin.

[0027] In a preferred embodiment, the coupling agent is selected from γ-aminopropyltriethoxysilane.

[0028] The present invention provides a graphene-modified PP resin antibacterial masterbatch. Sodium pyrithione is used as an antibacterial agent and has a good inhibitory effect on fungi. Graphene has a destructive effect on the cell membranes of microorganisms such as bacteria. The combination of the two can broaden the antibacterial spectrum, fight bacteria and fungi at the same time, and more comprehensively prevent the growth of microorganisms on the surface of polypropylene materials. In order to enable graphene and sodium pyrithione to achieve better antibacterial synergy, the graphene is first pretreated with a coupling agent, and calcium stearate is used as a dispersant to pretreat sodium pyrithione. At the same time, maleic anhydride grafted polypropylene and nano calcium carbonate are added to improve the dispersibility of the two in the PP resin to achieve better antibacterial synergy.

[0029] See also Figure 1 A method for preparing the above-mentioned graphene-modified PP resin antibacterial masterbatch, the preparation method comprising:

[0030] S10, adding graphene to an ethanol solution, adding a coupling agent for ultrasonic dispersion, and then removing the ethanol by rotary evaporation to obtain pretreated graphene.

[0031] In a specific embodiment, graphene is added to an appropriate amount of ethanol solution, and γ-aminopropyltriethoxysilane is added for ultrasonic dispersion to fully cover the surface of graphene with γ-aminopropyltriethoxysilane, and then the ethanol is removed by rotary evaporation.

[0032] In a preferred embodiment, the mass fraction of the coupling agent in step S10 is 1% to 5% of the graphene.

[0033] In a preferred embodiment, the ethanol solution in step S10 is 70% to 80% ethanol solution by volume.

[0034] S20, stirring and mixing sodium pyrithione and calcium stearate evenly, so that the calcium stearate is coated on the surface of sodium pyrithione to obtain pretreated sodium pyrithione.

[0035] In a specific embodiment, sodium pyrithione and an appropriate amount of calcium stearate are uniformly mixed under stirring in a high-speed mixer, so that the dispersant calcium stearate is coated on the surface of sodium pyrithione to improve its dispersibility.

[0036] In a preferred embodiment, the mass fraction of calcium stearate in step S20 is 5% to 20% of sodium pyrithione.

[0037] S30, mixing and stirring the nano calcium carbonate, maleic anhydride grafted polypropylene, antioxidant, pretreated graphene, pretreated sodium pyrithione and polypropylene to prepare graphene-modified PP resin antibacterial masterbatch.

[0038] In a preferred embodiment, the mixing and stirring in step S30 includes: firstly stirring the nano-calcium carbonate, maleic anhydride grafted polypropylene, antioxidant, pretreated graphene, pretreated sodium pyrithione and polypropylene at room temperature to obtain a mixture, and then heating and stirring the mixture at a high temperature, wherein the temperature of the warm heating and stirring is 180°C to 220°C.

[0039] In a specific embodiment, the pretreated graphene, the treated sodium pyrithione, nano calcium carbonate, maleic anhydride grafted polypropylene, hindered phenol antioxidant, phosphite antioxidant and PP resin are added to a high-speed mixer to make the components preliminarily mixed evenly, and the premixed materials are added to a twin-screw extruder for melt blending. The extruded materials are water-cooled, dried and pelletized to obtain graphene-modified PP resin particles.

[0040] In a preferred embodiment, in step S30, the mass fraction of maleic anhydride grafted polypropylene is 1% to 3% of polypropylene; the mass fraction of the antioxidant is 0.1% to 0.5% of polypropylene; the mass fraction of graphene is 1% to 5% of polypropylene; and the mass fraction of sodium pyrithione is 1% to 5% of graphene.

[0041] In a preferred embodiment, the mass ratio of nano-calcium carbonate to polypropylene in step S30 is 1:1.

[0042] Example 1

[0043] Example 1 provides a graphene-modified PP resin antibacterial masterbatch and a preparation method thereof, as follows:

[0044] A graphene-modified PP resin antibacterial masterbatch comprises the following components in parts by weight:

[0045] Polypropylene 100 parts;

[0046] 100 parts of nano calcium carbonate;

[0047] Graphene 3 parts;

[0048] Antibacterial agent (sodium pyrithione) 0.03 parts;

[0049] Dispersant (calcium stearate) 0.003 parts;

[0050] Compatibilizer (maleic anhydride grafted PP) 1 part;

[0051] Coupling agent (γ-aminopropyltriethoxysilane (KH-550)) 0.03 parts;

[0052] Hindered phenol antioxidant (antioxidant 1010) 0.1 part

[0053] 0.1 part of phosphite antioxidant (Antioxidant 168).

[0054] The preparation method of the graphene-modified PP resin antibacterial masterbatch is as follows:

[0055] (1) Pretreatment:

[0056] 3 parts of graphene were added to a 75% ethanol solution, and 0.03 parts of coupling agent KH-550 were added at the same time. Ultrasonic dispersion was performed for 30 minutes to allow the graphene surface to be fully coated with KH-550, and then rotary evaporation was performed at 60°C to remove the ethanol.

[0057] 0.03 parts of sodium pyrithione and 0.003 parts of calcium stearate were uniformly mixed under high-speed stirring at a mixing speed of 1000 r / min for 15 minutes to allow the dispersant calcium stearate to coat the surface of sodium pyrithione to improve its dispersibility.

[0058] (2) Premixing

[0059] The pretreated graphene, pretreated sodium pyrithione, nano-calcium carbonate, maleic anhydride grafted PP, antioxidant 1010, antioxidant 168 and PP resin were added into a high-speed mixer at a mixing speed of 1200 r / min for 20 minutes to make the components preliminarily mixed evenly.

[0060] (3) Melt blending

[0061] The premixed material obtained in step (2) is added to a twin-screw extruder for melt blending. The screw speed of the twin-screw extruder is 300 r / min, and the extrusion temperature is 180° C. to 220° C. The extruded material is water-cooled, dried, and pelletized to obtain a graphene-modified PP resin industrial masterbatch.

[0062] Example 2

[0063] Example 2 provides a graphene-modified PP resin antibacterial masterbatch and a preparation method thereof, as follows:

[0064] A graphene-modified PP resin antibacterial masterbatch comprises the following components in parts by weight:

[0065] Polypropylene 100 parts;

[0066] 100 parts of nano calcium carbonate;

[0067] Graphene 5 parts;

[0068] Antibacterial agent (sodium pyrithione) 0.05 parts;

[0069] Dispersant (calcium stearate) 0.005 parts;

[0070] Compatibilizer (maleic anhydride grafted PP) 1 part;

[0071] Coupling agent (γ-aminopropyltriethoxysilane (KH-550)) 0.05 parts

[0072] Hindered phenol antioxidant (antioxidant 1010) 0.1 part;

[0073] 0.1 part of phosphite antioxidant (Antioxidant 168).

[0074] The preparation method of the graphene-modified PP resin antibacterial masterbatch is as follows:

[0075] (1) Pretreatment:

[0076] 5 parts of graphene were added to a 75% ethanol solution, and 0.05 parts of coupling agent KH-550 were added at the same time. Ultrasonic dispersion was performed for 30 minutes to allow the graphene surface to be fully coated with KH-550, and then the ethanol was removed by rotary evaporation at 60°C.

[0077] 0.05 parts of sodium pyrithione and 0.005 parts of calcium stearate were uniformly mixed under high-speed stirring at a mixing speed of 1000 r / min for 15 minutes to allow the dispersant calcium stearate to coat the surface of sodium pyrithione to improve its dispersibility.

[0078] (2) Premixing

[0079] The pretreated graphene, pretreated sodium pyrithione, nano-calcium carbonate, maleic anhydride grafted PP, antioxidant 1010, antioxidant 168 and PP resin were added into a high-speed mixer at a mixing speed of 1200 r / min for 20 minutes to make the components preliminarily mixed evenly.

[0080] (3) Melt blending

[0081] The premixed materials are added to a twin-screw extruder for melt blending. The screw speed of the twin-screw extruder is 300r / min, and the extrusion temperature is 180℃~220℃. The extruded materials are water-cooled, dried, and pelletized to obtain graphene-modified PP resin industrial masterbatch.

[0082] Comparative Example 1

[0083] Comparative Example 1 is the control group of the above-mentioned Example 1. The PP resin industrial masterbatch in Comparative Example 1 does not contain graphene, and the other components are the same as those in Example 1.

[0084] Comparative Example 2

[0085] Comparative Example 2 is the control group of the above-mentioned Example 1. The PP resin industrial masterbatch in Comparative Example 2 does not pretreat the graphene, and the other components are the same as those in Example 1.

[0086] Comparative Example 3

[0087] Comparative Example 3 is the control group of the above-mentioned Example 2. The PP resin industrial masterbatch in Comparative Example 3 does not contain graphene, and the other components are the same as those in Example 2.

[0088] Comparative Example 4

[0089] Comparative Example 4 is the control group of the above-mentioned Example 2. The PP resin industrial masterbatch in Comparative Example 4 does not pretreat the graphene, and the other components are the same as those in Example 2.

[0090] The antibacterial performance of the PP resin industrial masterbatch samples obtained in the above Examples 1-2 and Comparative Examples 1-4 was tested, and the testing method is as follows:

[0091] Escherichia coli and Staphylococcus aureus were selected as sterilization objects, and the antibacterial properties were studied using the inhibition zone test method. A vernier caliper was used to measure the size of the inhibition zone around the sample. To ensure the accuracy of the data, the outermost edge of the inhibition zone should be measured during the measurement, and the experimental data should be recorded. The diameter of the inhibition zone on each plate was recorded, and the average value of the measurement results of different plates of the same strain was taken. The antibacterial performance test results are shown in Table 1 below:

[0092] sample Example 1 Comparative Example 1 Comparative Example 2 Inhibition zone (mm) 11.5 5.8 8.4 sample Example 2 Comparative Example 3 Comparative Example 4 Inhibition zone (mm) 13.2 6.1 8.9

[0093] Table 1 Antibacterial performance test data table

[0094] It can be seen from the test results in Table 1 that the modified PP resin antibacterial material prepared by adding oxidized graphene in Example 1 has good antibacterial effect, the graphene added in Comparative Example 2 has poor antibacterial effect without oxidation treatment, and no graphene is added in Comparative Example 1, which has antibacterial effect but poor antibacterial effect, which indicates that the PP resin antibacterial masterbatch obtained by graphene modification has good antibacterial effect.

[0095] It can be seen from the test results in Table 1 that the amount of graphene used in Example 2 is greater than that in Example 1, and the antibacterial effect of Example 2 obtained by increasing the amount of graphene is better than that of Example 1. And the antibacterial effects of Comparative Examples 3 and 4 obtained by comparison in Example 2 are better than those of Comparative Examples 1 and 2 obtained by comparison in Example 1. This shows that when the content of graphene increases, the antibacterial effect of the PP resin antibacterial masterbatch is also enhanced.

[0096] In summary, the graphene-modified PP resin antibacterial masterbatch provided by the present invention has good antibacterial properties, and the PP resin also has good mechanical properties, so that it can be widely used in various fields such as packaging.

[0097] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A graphene-modified PP resin antibacterial masterbatch, characterized in that: The graphene-modified PP resin antibacterial masterbatch comprises the following components in parts by weight: 100-150 parts of polypropylene, 100-150 parts of nano calcium carbonate, 2-10 parts of graphene, 0.01-0.1 parts of sodium pyrithione, 0.003-0.01 parts of calcium stearate, 1-5 parts of maleic anhydride grafted polypropylene, 0.03-0.08 parts of coupling agent, and 0.1-0.8 parts of antioxidant.

2. The graphene-modified PP resin antibacterial masterbatch according to claim 1, characterized in that: The antioxidant is selected from hindered phenol antioxidants and phosphite antioxidants.

3. The graphene-modified PP resin antibacterial masterbatch according to claim 1, characterized in that: The coupling agent is selected from γ-aminopropyltriethoxysilane.

4. A method for preparing graphene-modified PP resin antibacterial masterbatch as described in claims 1-3, characterized in that: The preparation method comprises: S10, adding graphene to an ethanol solution, adding a coupling agent at the same time for ultrasonic dispersion, and then removing the ethanol by rotary evaporation to obtain pretreated graphene; S20, stirring and mixing sodium pyrithione and calcium stearate evenly, so that the calcium stearate is coated on the surface of sodium pyrithione to obtain pretreated sodium pyrithione; S30, mixing and stirring the nano calcium carbonate, maleic anhydride grafted polypropylene, antioxidant, pretreated graphene, pretreated sodium pyrithione and polypropylene to prepare graphene-modified PP resin antibacterial masterbatch.

5. The method for preparing a graphene-modified PP resin antibacterial masterbatch according to claim 4, characterized in that: The ethanol solution in step S10 is 70% to 80% ethanol solution by volume.

6. The method for preparing a graphene-modified PP resin antibacterial masterbatch according to claim 4, characterized in that: The mixing and stirring in step S30 includes: firstly stirring the nano-calcium carbonate, maleic anhydride grafted polypropylene, antioxidant, pretreated graphene, pretreated sodium pyrithione and polypropylene at room temperature to obtain a mixture, and then heating and stirring the mixture at a high temperature, wherein the temperature of the warm heating and stirring is 180° C. to 220° C.

7. The method for preparing a graphene-modified PP resin antibacterial masterbatch according to claim 4, characterized in that: In step S30, the mass ratio of nano calcium carbonate to polypropylene is 1:

1.

8. The method for preparing a graphene-modified PP resin antibacterial masterbatch according to claim 4, characterized in that: In step S30, the mass fraction of maleic anhydride grafted polypropylene is 1% to 3% of polypropylene; the mass fraction of antioxidant is 0.1% to 0.5% of polypropylene; the mass fraction of graphene is 1% to 5% of polypropylene; and the mass fraction of sodium pyrithione is 1% to 5% of graphene.

9. The method for preparing a graphene-modified PP resin antibacterial masterbatch according to claim 4, characterized in that: The mass fraction of the coupling agent in step S10 is 1% to 5% of the graphene.

10. The method for preparing a graphene-modified PP resin antibacterial masterbatch according to claim 4, characterized in that: In the step S20, the mass fraction of calcium stearate is 5% to 20% of sodium pyrithione.

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