A method for preparing high-load-bearing polymer functional composite material based on 3D printing technology

Abstract

The present invention discloses a method for preparing a high-load-bearing polymer functional composite material based on 3D printing technology. By designing a mechanical metamaterial load-bearing skeleton structure and filling the mechanical metamaterial load-bearing skeleton structure with functional composite materials, it is ensured that the final product has good thermal conductivity, insulation, electromagnetic shielding and other properties. The purpose of the invention is to prepare a high-load-bearing polymer functional composite material product with both high mechanical load-bearing performance and strong functional properties. The specific preparation process steps involved in the invention method are: designing a mechanical metamaterial load-bearing skeleton structure model with good mechanical properties to meet the strength requirements of the product application scenario; using 3D printing technology to prepare a mechanical metamaterial load-bearing skeleton structure; filling the functional composite material filler into the mechanical metamaterial load-bearing skeleton structure by a specific method, and post-processing to obtain the final product. The integrated composite material prepared by the present invention can improve the functionality of the polymer material while also meeting certain mechanical properties.

Description

Technical Field

[0001] The present invention relates to a method for preparing a high-load-bearing polymer functional composite material using 3D printing technology, and specifically to a variety of polymer processing technologies such as the design of a mechanical metamaterial load-bearing skeleton structure; the preparation of a mechanical metamaterial load-bearing skeleton structure using polymer 3D printing; the preparation of a functional composite material filler; and the filling of a mechanical metamaterial load-bearing skeleton structure with a functional composite material filler. Background Art

[0002] The present invention is based on the traditional polymer composite material preparation method and proposes a high-load-bearing polymer functional composite material preparation method using 3D printing technology, which specifically involves the design of mechanical metamaterial load-bearing skeleton structure, 3D printing preparation of mechanical metamaterial load-bearing skeleton structure, preparation of functional composite material fillers, and filling of mechanical metamaterial load-bearing skeleton structure with functional composite material fillers.

[0003] The high-load-bearing polymer functional composite material is composited by a mechanical metamaterial load-bearing skeleton structure and a functional composite material filler. The composite process of the mechanical metamaterial load-bearing skeleton structure and the functional composite material filler is the focus of the present invention. It is a preparation method for a high-load-bearing polymer functional composite material based on polymer 3D printing technology and functional composite material preparation technology.

[0004] The mechanical metamaterial load-bearing skeleton structure is designed through 3D drawing software (such as SolidWorks, ProE, etc.).

[0005] High-load-bearing polymer functional composite materials prepared based on 3D printing technology can meet the mechanical load-bearing requirements of the final product while occupying a relatively small space of the skeleton structure by designing the mechanical metamaterial load-bearing skeleton structure of the composite material.

[0006] The processing methods for preparing mechanical metamaterial load-bearing skeleton structures using 3D printing technology include but are not limited to fused deposition modeling (FDM), selective laser sintering (SLS), stereolithography (SLA) and three-dimensional inkjet printing (3DP).

[0007] Appropriate modification of the load-bearing skeleton structure of mechanical metamaterials and the functional composite material fillers can improve the compatibility between the two. Summary of the invention

[0008] The present invention proposes a method for preparing a high-load-bearing polymer functional composite material based on 3D printing technology, which provides a new idea for the composite research on the structure and functional properties of traditional polymer composite materials.

[0009] The core technical points of the method for preparing high-load-bearing polymer functional composite materials based on 3D printing technology proposed in the present invention are: the design of the load-bearing skeleton structure of the mechanical metamaterial to improve the mechanical properties of the composite product; the preparation of composite fillers with different functional properties; the filling process of the mechanical metamaterial load-bearing skeleton structure with the composite filler, etc.

[0010] A method for preparing a high-load-bearing polymer functional composite material based on 3D printing technology, the inventive method comprises the following specific steps:

[0011] Step 1: Design of the load-bearing skeleton structure of mechanical metamaterials

[0012] Three-dimensional modeling software (such as SolidWorks, ProE and other three-dimensional modeling software) is used to design the mechanical metamaterial load-bearing skeleton structure to ensure that it has good mechanical properties (including but not limited to high load-bearing capacity, tensile resistance, impact resistance, etc.).

[0013] The mechanical metamaterial load-bearing skeleton structure designed by three-dimensional modeling includes but is not limited to three-dimensional porous structure, spatial truss structure and spatial hexagonal structure.

[0014] The study is based on the effect of porosity size on specific structural strength in different spatial topological structure models, in order to obtain excellent mechanical properties with a small proportion of solid space.

[0015] Step 2: 3D printing to prepare the mechanical metamaterial load-bearing skeleton structure

[0016] The 3D printing technology is used to prepare the mechanical metamaterial load-bearing skeleton structure. The processing methods of 3D printing the mechanical metamaterial load-bearing skeleton structure include but are not limited to fused deposition modeling (FDM), selective laser sintering (SLS), stereolithography (SLA) and stereo inkjet printing (3DP).

[0017] Materials for preparing mechanical metamaterial load-bearing skeleton structures include, but are not limited to, single polymer materials such as thermoplastic polymers (such as polypropylene, polyethylene, polycarbonate, etc.), thermosetting polymers (polydimethylsiloxane, epoxy resin, etc.), photocurable resin materials and elastomeric materials (rubber), as well as skeleton structure composite materials with functional properties prepared by composite processing methods.

[0018] Step 3: Preparation of functional composite fillers

[0019] The functional composite material filler prepared has functional properties including but not limited to thermal conductivity, insulation and electromagnetic shielding.

[0020] Functional composite material fillers are prepared. Applicable functional filler materials include but are not limited to inorganic non-metallic materials (such as graphene, nano-boron nitride, carbon nanotubes, silicon carbide, etc.) and metal oxides (aluminum oxide, bismuth oxide, beryllium oxide and magnesium oxide, etc.).

[0021] Step 4: Fill the mechanical metamaterial load-bearing skeleton structure with functional composite fillers

[0022] This step is the focus and highlight of the present invention, emphasizing the combination of a supportable mechanical metamaterial polymer skeleton structure and a functional composite filler.

[0023] Appropriate modification is performed on the load-bearing skeleton structure of the mechanical metamaterial and the functional composite material filler to improve the compatibility between the two.

[0024] Methods for filling functional composite fillers into the load-bearing skeleton structure of mechanical metamaterials include but are not limited to vacuum negative pressure method, ultrasonic forced infiltration method, etc.

[0025] Step 5: Post-processing of high-load-bearing polymer functional composites

[0026] The post-processing methods of the high-load polymer functional composite material include but are not limited to constant temperature curing, heating and pressing, and magnetic field induction method, etc., to enhance the interface compatibility between the mechanical metamaterial load-bearing skeleton structure and the functional composite filler, etc., to obtain the final product of the high-load polymer functional composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Shown is a designed spatial cube mechanical metamaterial load-bearing skeleton structure model.

[0028] Figure 2 Shown is a designed spatial truss mechanics metamaterial load-bearing skeleton structure model.

[0029] Figure 3 Shown is a designed model of a load-bearing skeleton structure of a spatial curved surface mechanical metamaterial.

[0030] Figure 4 Shown are three actual pictures of mechanical metamaterial load-bearing skeleton structures prepared by 3D printing.

[0031] Figure 5 Shown is a physical picture of a high-load-bearing polymer thermal conductive composite material prepared. DETAILED DESCRIPTION

[0032] The implementation process of the present invention is described in detail below. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0033] Example 1: Preparation of high-load-bearing thermal conductive composite materials of nano boron nitride / epoxy resin@polylactic acid (BNNS / Epoxy@PLA)

[0034] Example 1 includes the following specific steps:

[0035] Step 1: Design a mechanical metamaterial load-bearing skeleton structure model for high-load-bearing thermal conductive composite materials

[0036] Mechanical metamaterial load-bearing skeleton structure modeling of high-load-bearing thermal conductive composite materials, the designed polymer mechanical metamaterial load-bearing skeleton model is as follows Figure 1 The designed skeleton structure has good mechanical test performance (high load-bearing, tensile resistance, impact resistance, etc.).

[0037] Step 2: 3D printing to prepare polymer mechanical metamaterial load-bearing skeleton structure

[0038] The fused deposition model (FDM) method is used to prepare the mechanical metamaterial load-bearing skeleton structure. The mechanical metamaterial load-bearing skeleton model established in step 1 is imported into the 3D printing software to set the parameters of the 3D printing process. The set parameters include but are not limited to nozzle diameter, nozzle temperature, platform temperature, number of layers, printing start position, etc.

[0039] Polylactic acid (PLA) is selected as the load-bearing skeleton material of the mechanical metamaterial.

[0040] Step 3: Preparation of nano boron nitride / epoxy resin (BNNS / Epoxy) thermal conductive composite filler

[0041] Preparation of nano boron nitride / epoxy resin (BNNS / Epoxy) thermal conductive composite filler. Using a physical blending method, BNNS and Epoxy with a mass fraction of 2:8 were mixed; and stirred at 2000r / min for 3 minutes by a homogenizer; and the bubbles generated during the stirring process were removed by vacuum filtration for 2 minutes; finally, a curing agent with a mass fraction ratio of 1 / 10 to the epoxy resin was added and stirred thoroughly to obtain the final BNNS / Epoxy thermal conductive composite filler.

[0042] Step 4: Fill the PLA polymer mechanical metamaterial skeleton structure with BNNS / Epoxy thermal conductive composite filler

[0043] First, place the PLA polymer skeleton structure on a heating platform at 120°C; fill the prepared BNNS / Epoxy thermal conductive composite filler into the PLA polymer skeleton structure; the filled product is a nano boron nitride / epoxy resin@polylactic acid (BNNS / Epoxy@PLA) high-load-bearing thermal conductive composite material.

[0044] Step 5: Post-processing of BNNS / Epoxy@PLA high-load thermal conductive composite material

[0045] The high-load-bearing thermally conductive composite material obtained in step 4 is post-processed by heating and pressurizing at 60°C and 2Mpa for 30 minutes to strengthen the structure of the product, enhance the effective network structure inside the thermally conductive composite material, and improve the compatibility of the skeleton structure and the thermally conductive composite filler.

[0046] The BNNS / Epoxy@PLA high-load-bearing thermal conductive composite material prepared through the above process has the final product that has both the load-bearing properties of mechanical metamaterials and thermal conductivity. The above preparation process provides a new idea for the research of high-load-bearing thermal conductive composite materials.

[0047] Example 2: Preparation of high-load-bearing thermally conductive insulating composite material of nano boron nitride / aluminum oxide / polydimethylsiloxane@light-curable resin (BNNS / Al2O3 / PDMS@UVCurable Resin)

[0048] Example 2 includes the following specific steps:

[0049] Step 1: Design a mechanical metamaterial load-bearing skeleton structure for high-load-bearing thermally conductive and insulating composite materials

[0050] Design a mechanical metamaterial skeleton structure model for high-load-bearing thermal conductive insulation composite materials. The designed mechanical metamaterial load-bearing skeleton model is as follows Figure 2 As shown. The mechanical metamaterial load-bearing skeleton structure has good mechanical test performance (high load-bearing, tensile resistance, impact resistance, etc.).

[0051] Step 2: 3D printing to prepare the mechanical metamaterial load-bearing skeleton structure

[0052] Stereolithography (SLA) is used to prepare the load-bearing skeleton structure. The mechanical metamaterial load-bearing skeleton model of the high-load-bearing thermal conductive insulating composite material designed in step 1 is sliced ​​to determine the printing path, layer thickness, etc.; the set skeleton model is exported as an STL file format and stored in the SLA-3D printer; the relevant printing parameters (including but not limited to ultraviolet light intensity, scanning speed, exposure time, etc.) are set.

[0053] UV Curable Resin is selected as the load-bearing skeleton structure material of the mechanical metamaterial.

[0054] Step 3: Preparation of nano boron nitride / aluminum oxide / polydimethylsiloxane (BNNS / Al2O3 / PDMS) thermally conductive and insulating composite filler

[0055] Hexagonal boron nitride (h-BN) was used as raw material, and BNNS with high thermal conductivity was prepared by mechanical ball milling and exfoliation, and dopamine was used to modify BNNS; industrial-grade alumina (Al2O3) powder was selected, ground, and modified with silane coupling agent KH550; the treated BNNS and Al2O3 were mixed in a ratio of 2:1 and then evenly ground; the BNNS / Al2O3 mixed material prepared in the above and PDMS were mixed and stirred in a mass fraction of 2:8, put into a homogenizer and stirred at 2000r / min for 3min, and vacuum filtered for 2 minutes to remove the bubbles generated during the stirring process; finally, a curing agent with a mass fraction ratio of 1 / 10 to PDMS was added and stirred thoroughly. The above steps are the implementation process of preparing BNNS / Al2O3 / PDMS thermal conductive insulating composite filler.

[0056] Step 4: Filling the load-bearing skeleton structure of the mechanical metamaterial with thermally conductive and insulating composite fillers

[0057] The mechanical metamaterial load-bearing skeleton structure prepared above is placed on a 60°C heating platform; secondly, the BNNS / Al2O3 / PDMS thermally conductive insulating composite filler prepared in step three is used to fill the mechanical metamaterial load-bearing skeleton structure, and the obtained product is a nano boron nitride / aluminum oxide / polydimethylsiloxane@light-curable resin (BNNS / Al2O3 / PDMS@UV CurableResin) high-load-bearing thermally conductive insulating composite material.

[0058] Step 5: Post-processing of BNNS / Al2O3 / PDMS@UV Curable Resin high-load thermal conductive insulation composite material

[0059] The product obtained in step 4 is subjected to magnetic field induction to enhance the effective network structure in the thermally conductive insulating composite filler; the thermally conductive insulating composite filler and the mechanical metamaterial load-bearing skeleton structure are effectively combined by ultrasonic forced infiltration; finally, the product is subjected to heating and pressurization treatment at 60°C and 2Mpa for 12 hours to enhance the structure of the product. The final BNNS / Al2O3 / PDMS@UV Curable Resin high-load thermally conductive insulating composite material is obtained.

[0060] The BNNS / Al2O3 / PDMS@UV Curable Resin high-load thermally conductive insulating composite material prepared by the above process enables the polymer composite material to have both thermal conductive and insulating functional properties on the basis of high load-bearing properties. The above preparation process provides a new idea for the research of high-load thermally conductive insulating composite materials.

[0061] Example 3: Graphene oxide / ferroferric oxide / polydimethylsiloxane@UV Curable Resin (GO / Fe3O4 / PDMS@UV Curable Resin) high-load electromagnetic shielding composite material

[0062] Example 3 includes the following specific steps:

[0063] Step 1: Design a mechanical metamaterial load-bearing skeleton structure for high-load electromagnetic shielding composite materials

[0064] Design a mechanical metamaterial load-bearing skeleton structure model for high-load electromagnetic shielding composite materials, and design a mechanical load-bearing skeleton structure such as Figure 3 The mechanical metamaterial load-bearing skeleton structure should have good mechanical test performance (such as high load-bearing capacity, tensile resistance, impact resistance, etc.).

[0065] Step 2: 3D printing to prepare the mechanical metamaterial load-bearing skeleton structure

[0066] Stereolithography (SLA) was used to prepare the mechanical metamaterial load-bearing skeleton structure. The mechanical metamaterial skeleton model of the high-load electromagnetic shielding composite material designed in step 1 was sliced ​​to determine the printing path, layer thickness, etc.; the set skeleton model was exported as an STL file format and stored in the SLA-3D printer; and the relevant printing parameters (including but not limited to ultraviolet light intensity, scanning speed, exposure time, etc.) were set.

[0067] UV Curable Resin is selected as the load-bearing skeleton structure material of the mechanical metamaterial.

[0068] Step 3: Preparation of graphene oxide / ferroferric oxide / polydimethylsiloxane (GO / Fe3O4 / PDMS) electromagnetic shielding composite filler

[0069] Graphene oxide (GO) and ferroferric oxide (Fe3O4) in a mass fraction ratio of 1:1 were uniformly mixed to obtain a GO / Fe3O4 mixed material, and the GO / Fe3O4 mixed material and polydimethylsiloxane (PDMS) were stirred in a mass fraction of 2:8 to obtain GO / Fe3O4 / PDMS; the obtained GO / Fe3O4 / PDMS was put into a homogenizer and uniformly stirred at 2000r / min for 3min; then vacuum treatment was used for 2min to remove excess bubbles, and finally, a curing agent in a mass fraction ratio of 1 / 10 to PDMS was added and fully stirred. After uniform mixing, a GO / Fe3O4 / PDMS electromagnetic shielding composite filler was obtained.

[0070] Step 4: Filling the load-bearing skeleton structure of the mechanical metamaterial with electromagnetic shielding composite fillers

[0071] First, the UV resin skeleton structure formed by light curing in step 2 is placed on a heating platform; the GO / Fe3O4 / PDMS composite filler with electromagnetic shielding performance prepared in step 4 is filled into the skeleton structure at a certain angle. The filling results in a GO / Fe3O4 / PDMS@UV Curable Resin high-load electromagnetic shielding composite material product.

[0072] Step 5: Post-treatment of GO / Fe3O4 / PDMS@UV Curable Resin high-load electromagnetic shielding composite material

[0073] The product obtained in step 4 uses a magnetic field induction method to enhance the effective network in the electromagnetic shielding composite material; heat and pressurize for 12 hours at 60°C and 2Mpa to enhance the structure of the product and promote the surface compatibility of the electromagnetic shielding composite filler and the mechanical metamaterial load-bearing skeleton structure. Finally, a GO / Fe3O4 / PDMS@UV Curable Resin high-load electromagnetic shielding composite material is prepared.

[0074] The GO / Fe3O4 / PDMS@UV resin high-load electromagnetic shielding composite material prepared by the above process has good mechanical test performance (impact resistance, tensile strength, support, etc.) and electromagnetic shielding functional properties, providing a new idea for the research of high-load electromagnetic shielding composite materials.

Claims

1. A method for preparing a high-load-bearing polymer functional composite material based on 3D printing technology, wherein the high-load-bearing polymer functional composite material is a nano boron nitride / aluminum oxide / polydimethylsiloxane@photocurable resin high-load-bearing thermal conductive insulation composite material, and the preparation method comprises the following steps: Step 1: Design a mechanical metamaterial load-bearing skeleton structure of a high-load-bearing thermal conductive insulating composite material: Use 3D modeling software to design a mechanical metamaterial load-bearing skeleton structure; Step 2: 3D printing to prepare the mechanical metamaterial load-bearing skeleton structure: Use stereolithography to prepare the load-bearing skeleton structure: Slice the mechanical metamaterial load-bearing skeleton model of the high-load-bearing thermal conductive insulation composite material designed in step 1, determine the printing path and layer thickness; export the set skeleton model as an STL file format and store it in the SLA-3D printer; Set relevant printing parameters; select photocurable resin as the load-bearing skeleton structure material of mechanical metamaterials; Step 3: Preparation of nano boron nitride / aluminum oxide / polydimethylsiloxane thermal conductive insulating composite filler: Hexagonal boron nitride is used as raw material, and BNNS with high thermal conductivity is prepared by mechanical ball milling and exfoliation method, and dopamine is used to modify BNNS; industrial-grade alumina powder is selected, ground and modified with silane coupling agent KH550; the treated BNNS and alumina are mixed in a ratio of 2:1 and then ground evenly to obtain a BNNS / Al2O3 mixed material; the BNNS / Al2O3 mixed material and PDMS are mixed and stirred in a mass fraction of 2:8, and then placed in a homogenizer and stirred at 2000r / min for 3min, and vacuum filtered for 2 minutes to remove bubbles generated during the stirring process; finally, a curing agent is added in a mass fraction ratio of 1 / 10 to PDMS and stirred thoroughly to obtain a BNNS / Al2O3 / PDMS thermal conductive insulating composite filler; Step 4: Filling the load-bearing skeleton structure of the mechanical metamaterial with a thermally conductive insulating composite filler: placing the prepared mechanical metamaterial load-bearing skeleton structure on a 60°C heating table; secondly, filling the mechanical metamaterial load-bearing skeleton structure with the BNNS / Al2O3 / PDMS thermally conductive insulating composite filler prepared in step 3, and the obtained product is a nano boron nitride / aluminum oxide / polydimethylsiloxane@photocurable resin high-load-bearing thermally conductive insulating composite material; Step 5: Post-processing of products: Use magnetic field induction method to enhance the effective network structure of thermally conductive insulating composite filler in the product obtained in step 4; then use ultrasonic forced infiltration method to effectively combine the thermally conductive insulating composite filler and the mechanical metamaterial load-bearing skeleton structure; finally, heat and pressurize the product at 60°C and 2Mpa for 12 hours to enhance the structure and obtain the final high-load thermally conductive insulating composite material.

2. A method for preparing a high-load polymer functional composite material based on 3D printing technology, wherein the high-load polymer functional composite material is a graphene oxide / ferrous oxide / polydimethylsiloxane@photocurable resin high-load electromagnetic shielding composite material, and the preparation method comprises the following steps: Step 1: Design a mechanical metamaterial load-bearing skeleton structure of a high-load electromagnetic shielding composite material: Use 3D modeling software to design a mechanical metamaterial load-bearing skeleton structure; Step 2: 3D printing to prepare the mechanical metamaterial load-bearing skeleton structure: Use stereolithography to prepare the mechanical metamaterial load-bearing skeleton structure, slice the mechanical metamaterial skeleton model of the high-load electromagnetic shielding composite material designed in step 1, and determine the printing path and layer thickness; export the set skeleton model as an STL file format and store it in the SLA-3D printer; Set relevant printing parameters; select photocurable resin as the load-bearing skeleton structure material of mechanical metamaterials; Step 3: Preparation of graphene oxide / ferroferric oxide / polydimethylsiloxane electromagnetic shielding composite filler: Graphene oxide and ferroferric oxide in a mass fraction ratio of 1:1 are uniformly mixed to obtain a GO / Fe3O4 mixed material, the GO / Fe3O4 mixed material and PDMS are stirred in a mass fraction of 2:8, and then put into a homogenizer and uniformly stirred at 2000r / min for 3min; then vacuum treatment is used for 2min to remove excess bubbles, and finally, a curing agent in a mass fraction ratio of 1 / 10 to PDMS is added and fully stirred, and a GO / Fe3O4 / PDMS electromagnetic shielding composite filler is obtained after uniform mixing; Step 4: Filling the load-bearing skeleton structure of the mechanical metamaterial with electromagnetic shielding composite fillers: placing the UV resin skeleton structure formed by photocuring in step 2 on a heating platform; filling the GO / Fe3O4 / PDMS electromagnetic shielding composite filler with electromagnetic shielding performance prepared in step 3 into the skeleton structure at a certain angle, and the product obtained after filling is a graphene oxide / ferrous oxide / polydimethylsiloxane@photocuring resin high-load electromagnetic shielding composite material; Step 5: Post-processing of the product: Use a magnetic field induction method to enhance the effective network in the electromagnetic shielding composite material of the product obtained in step 4; heat and pressurize the product at 60°C and 2Mpa for 12 hours to enhance the structure of the product, promote the surface compatibility of the electromagnetic shielding composite filler and the mechanical metamaterial load-bearing skeleton structure, and finally prepare a high-load electromagnetic shielding composite material.

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