Environment-friendly engineering plastic based on graphene or titanium dioxide composite reinforcement and preparation process thereof

Abstract

The invention relates to the technical field of engineering plastics, in particular to an environment-friendly engineering plastic based on composite reinforcement of graphene or titanium dioxide and a preparation process of the environment-friendly engineering plastic. The composite material is prepared from the following components in parts by weight: 30 to 60 parts of polylactic acid, 0.5 to 5 parts of graphene, 2 to 10 parts of nano titanium dioxide, 5 to 15 parts of ethylene-octylene copolymer, 2 to 8 parts of maleic anhydride grafted polypropylene, 0.1 to 1 part of hindered phenol antioxidant 1010 and 0.5 to 2 parts of calcium stearate. A proper amount of graphene and nano titanium dioxide are added to form a good composite structure with a polylactic acid matrix, so that the tensile strength, bending strength and impact strength of the engineering plastic are effectively improved. Due to the high strength and high modulus characteristics of graphene and the enhancement effect of nano titanium dioxide, the mechanical property of the material is remarkably improved, and more application scenes with high strength requirements can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering plastics, in particular to an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement and a preparation process thereof. Background Art

[0002] Engineering plastics, a class of materials with excellent comprehensive properties, are widely used in numerous fields. However, with growing environmental awareness and increasing demands for material performance, traditional engineering plastics are no longer able to meet these demands in certain areas. On the one hand, their mechanical properties need to be further improved to adapt to more demanding operating environments; on the other hand, the development of biodegradable or environmentally friendly engineering plastics is needed to reduce environmental pollution.

[0003] Graphene has excellent mechanical, electrical and thermal properties, such as high strength, high modulus, high electrical conductivity and high thermal conductivity. Introducing graphene into engineering plastics is expected to significantly improve the mechanical, electrical and thermal properties of engineering plastics. Titanium dioxide has good photocatalytic properties, chemical stability and antibacterial properties. Adding titanium dioxide to engineering plastics can give the material the ability to photocatalytically degrade organic pollutants and improve the material's weather resistance and antibacterial properties. At present, although there are some research reports on adding graphene or titanium dioxide to engineering plastics, most of them have problems such as complex preparation process, high cost, and insignificant improvement in material performance. To this end, an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement and its preparation process are proposed. Summary of the Invention

[0004] In view of this, the present invention provides an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement and a preparation process thereof to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0005] The technical solution of the present invention is achieved as follows: an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement is composed of the following parts by weight: 30-60 parts of polylactic acid, 0.5-5 parts of graphene, 2-10 parts of nano titanium dioxide, 5-15 parts of ethylene-octene copolymer, 2-8 parts of maleic anhydride grafted polypropylene, 0.1-1 parts of hindered phenol antioxidant 1010 and 0.5-2 parts of calcium stearate.

[0006] A preparation process of environmentally friendly engineering plastics based on graphene or titanium dioxide composite reinforcement comprises the following steps:

[0007] Step 1: pretreatment of graphene;

[0008] Step 2: Surface modification of nano-titanium dioxide;

[0009] Step 3: Mix the raw materials;

[0010] Step 4: melt blending;

[0011] Step 5: Granulation and molding.

[0012] Further preferably, in step 1, the graphene is added to a 5%-10% by mass nitric acid solution and ultrasonically dispersed for 30-60 minutes at an ultrasonic power of 200-400 W, then filtered and washed until neutral, and dried at 80-100° C. for 12-24 hours. The purpose of this step is to oxidize the surface of the graphene, increase its surface active groups, and improve its compatibility with the matrix resin.

[0013] Further preferably, in step 2, the nano-titanium dioxide is added to anhydrous ethanol and uniformly dispersed by ultrasonication, and then a silane coupling agent KH550 is added at a concentration of 3% to 5% by weight of the nano-titanium dioxide. The mixture is stirred and reacted at 60-80°C for 2-4 hours, followed by centrifugation, washing, and drying. The surface-modified nano-titanium dioxide can be better dispersed in the matrix resin, enhancing the interfacial bonding strength with the resin.

[0014] Further preferably, in the step three, the pretreated graphene, surface-modified nano-titanium dioxide, polylactic acid, ethylene-octene copolymer, maleic anhydride grafted polypropylene, antioxidant 1010 and calcium stearate are added to a high-speed mixer according to the formula ratio, and mixed for 10-20 minutes at a speed of 800-1200 r / min to ensure that the components are fully mixed.

[0015] Further preferably, in step 4, the mixed raw materials are added to a twin-screw extruder for melt blending. The temperature of the twin-screw extruder is set as follows: zone 1 temperature 160-180°C, zone 2 temperature 170-190°C, zone 3 temperature 180-200°C, zone 4 temperature 190-210°C, die head temperature 200-220°C, and screw speed 200-300 r / min. Through melt blending, the components are fused together under high temperature and pressure to form a uniform composite material.

[0016] Further preferably, in step 5, the extruded blend is pelletized using a water-cooled strand pelletizer to produce engineering plastic particles. The particles are then processed into various plastic products using molding equipment such as an injection molding machine and an extruder, depending on actual needs. During injection molding, the injection temperature is 190-220°C and the injection pressure is 80-120 MPa; during extrusion molding, the extrusion temperature is 180-210°C and the screw speed is 100-200 r / min.

[0017] The embodiment of the present invention adopts the above technical solution, which has the following advantages:

[0018] First, this invention effectively improves the tensile, flexural, and impact strengths of engineering plastics by adding appropriate amounts of graphene and nano-titanium dioxide to form a composite structure with a polylactic acid matrix. The high strength and high modulus of graphene, combined with the reinforcing effect of nano-titanium dioxide, significantly enhance the material's mechanical properties, enabling it to meet a wider range of high-strength application scenarios.

[0019] Second, the present invention uses polylactic acid as the base resin, which is biodegradable and gradually decomposes into carbon dioxide and water in the natural environment, reducing the environmental pollution caused by plastic waste. Furthermore, the additives and treatment methods used throughout the entire production process are environmentally friendly, in line with the concept of green chemistry.

[0020] 3. The addition of nano-titanium dioxide in the present invention gives engineering plastics photocatalytic properties, which can degrade organic pollutants in the environment; its good chemical stability improves the weather resistance of the material and extends the service life of the material in outdoor environments; in addition, nano-titanium dioxide also has certain antibacterial properties, which can inhibit the growth and reproduction of bacteria and other microorganisms on the surface of the material.

[0021] 4. The preparation process of the present invention has relatively simple operation steps and does not require complex equipment and high-end technology. The raw materials used, such as polylactic acid, graphene, and nano-titanium dioxide, can be easily obtained on the market at a relatively low cost, making it suitable for large-scale industrial production and having good economic benefits and market prospects.

[0022] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 It is a flow chart of the preparation process of the present invention. DETAILED DESCRIPTION

[0025] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] like Figure 1 As shown, an embodiment of the present invention provides an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement, which is composed of the following parts by weight: 30-60 parts of polylactic acid, 0.5-5 parts of graphene, 2-10 parts of nano titanium dioxide, 5-15 parts of ethylene-octene copolymer, 2-8 parts of maleic anhydride grafted polypropylene, 0.1-1 parts of hindered phenol antioxidant 1010 and 0.5-2 parts of calcium stearate.

[0028] A preparation process of environmentally friendly engineering plastics based on graphene or titanium dioxide composite reinforcement comprises the following steps:

[0029] Step 1: pretreatment of graphene;

[0030] Step 2: Surface modification of nano-titanium dioxide;

[0031] Step 3: Mix the raw materials;

[0032] Step 4: melt blending;

[0033] Step 5: Granulation and molding.

[0034] In one embodiment, in step 1, the graphene is added to a 5%-10% by mass nitric acid solution and ultrasonically dispersed at an ultrasonic power of 200-400 W for 30-60 minutes. The solution is then filtered, washed until neutral, and dried at 80-100° C. for 12-24 hours. This step is to oxidize the graphene surface, increase its surface active groups, and improve its compatibility with the matrix resin.

[0035] In one embodiment, in step 2, nano-titanium dioxide is added to anhydrous ethanol and uniformly dispersed by ultrasonication. A silane coupling agent, KH550, is then added at a concentration of 3% to 5% by weight of the nano-titanium dioxide. The mixture is stirred and reacted at 60-80°C for 2-4 hours. The mixture is then centrifuged, washed, and dried. The surface-modified nano-titanium dioxide can be better dispersed in the matrix resin, enhancing interfacial bonding with the resin.

[0036] In one embodiment, in step three, pretreated graphene, surface-modified nano-titanium dioxide, polylactic acid, ethylene-octene copolymer, maleic anhydride grafted polypropylene, antioxidant 1010 and calcium stearate are added to a high-speed mixer according to the formula ratio, and mixed at a speed of 800-1200 r / min for 10-20 minutes to ensure that the components are fully mixed.

[0037] In one embodiment, in step 4, the mixed raw materials are added to a twin-screw extruder for melt blending. The twin-screw extruder is set to the following temperatures: zone 1: 160-180°C, zone 2: 170-190°C, zone 3: 180-200°C, zone 4: 190-210°C, die head temperature: 200-220°C, and screw speed: 200-300 rpm. Through melt blending, the components are fused together under high temperature and pressure to form a uniform composite material.

[0038] In one embodiment, in step five, the extruded blend is pelletized using a water-cooled strand pelletizer to produce engineering plastic particles. The particles are then processed into various plastic products using molding equipment such as injection molding machines and extruders, depending on actual needs. During injection molding, the injection temperature is 190-220°C and the injection pressure is 80-120 MPa; during extrusion molding, the extrusion temperature is 180-210°C and the screw speed is 100-200 r / min.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various modifications and substitutions within the technical scope disclosed in the present invention, and such modifications and substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement, characterized by: The invention is composed of the following parts by weight: 30-60 parts of polylactic acid, 0.5-5 parts of graphene, 2-10 parts of nano titanium dioxide, 5-15 parts of ethylene-octene copolymer, 2-8 parts of maleic anhydride grafted polypropylene, 0.1-1 parts of hindered phenol antioxidant 1010 and 0.5-2 parts of calcium stearate.

2. A process for preparing an environmentally friendly engineering plastic reinforced with graphene or titanium dioxide, in combination with the environmentally friendly engineering plastic reinforced with graphene or titanium dioxide as claimed in claim 1, characterized in that: The following steps are involved: Step 1: pretreatment of graphene; Step 2: Surface modification of nano-titanium dioxide; Step 3: Mix the raw materials; Step 4: melt blending; Step 5: Granulation and molding.

3. The process for preparing an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement according to claim 2, characterized in that: In step 1, the graphene is added to a 5% to 10% nitric acid solution by mass and ultrasonically dispersed for 30 to 60 minutes at an ultrasonic power of 200 to 400 W. The solution is then filtered, washed until neutral, and dried at 80 to 100° C. for 12 to 24 hours. This step is intended to oxidize the graphene surface, increase its surface active groups, and improve its compatibility with the matrix resin.

4. The process for preparing an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement according to claim 2, characterized in that: In step 2, nano-titanium dioxide is added to anhydrous ethanol and uniformly dispersed by ultrasonication. A silane coupling agent, KH550, is then added at a concentration of 3% to 5% by weight of the nano-titanium dioxide. The mixture is stirred at 60-80°C for 2-4 hours, followed by centrifugation, washing, and drying. The surface-modified nano-titanium dioxide can be better dispersed in the matrix resin, enhancing interfacial bonding with the resin.

5. The process for preparing an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement according to claim 2, characterized in that: In the step three, the pretreated graphene, surface-modified nano-titanium dioxide, polylactic acid, ethylene-octene copolymer, maleic anhydride grafted polypropylene, antioxidant 1010 and calcium stearate are added to a high-speed mixer according to the formula ratio, and mixed for 10-20 minutes at a speed of 800-1200 r / min to ensure that the components are fully mixed.

6. The process for preparing an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement according to claim 2, characterized in that: In step 4, the mixed raw materials are added to a twin-screw extruder for melt blending. The twin-screw extruder is set to the following temperatures: zone 1: 160-180°C, zone 2: 170-190°C, zone 3: 180-200°C, zone 4: 190-210°C, die head temperature: 200-220°C, and screw speed: 200-300 rpm. Through melt blending, the components are fused together under high temperature and pressure to form a uniform composite material.

7. The process for preparing an environmentally friendly engineering plastic based on graphene or titanium dioxide composite reinforcement according to claim 2, characterized in that: In step five, the extruded blend is pelletized in a water-cooled strand pelletizer to produce engineering plastic particles. The particles are then processed into various plastic products using molding equipment such as injection molding machines and extruders, depending on actual needs. During injection molding, the injection temperature is 190-220°C and the injection pressure is 80-120 MPa; during extrusion molding, the extrusion temperature is 180-210°C and the screw speed is 100-200 rpm.

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