Basalt fiber reinforced composite foam material and preparation method thereof

Abstract

The invention provides a basalt fiber reinforced composite foam material and a preparation method thereof, and relates to the technical field of high polymer materials. The basalt fiber BF is added into the composite foam material, the mechanical interlocking effect of foam and a matrix can be enhanced, the mechanical property of the material is improved, meanwhile, the silicon dioxide component is introduced, an effective heat conduction path is provided for the composite foam material, the heat conduction performance of the composite foam material is effectively improved, and the thermal conductivity of the composite foam material is improved. The requirement of the composite foam material on a high-strength structure is met, and the composite foam material has important academic value and industrialization prospect.

Description

Technical Field

[0001] This invention provides a basalt fiber reinforced composite foam material and its preparation method, belonging to the field of polymer technology. Background Technology

[0002] Syntactic foams are widely used in deep-sea equipment and insulation structures due to their lightweight, high buoyancy, and low water absorption. However, these materials still have significant drawbacks in terms of thermal conductivity and mechanical strength. The main problem lies in the weak interfacial bonding between the microspheres and the resin matrix, resulting in insufficient structural continuity. Under long-term exposure to high pressure, alternating damp heat, or mechanical stress, stress concentration easily occurs at the interface, leading to interfacial separation and significantly reducing the material's mechanical properties. Furthermore, due to the difference in thermal expansion coefficients between the microspheres and the resin, microcracks or pores are easily generated during temperature cycling, affecting the material's thermal stability and structural integrity. Simultaneously, the non-uniformity of the internal microstructure also leads to fluctuations in mechanical properties and the formation of weak areas, making them more susceptible to failure under external forces and compromising reliability.

[0003] Basalt fiber, due to its low coefficient of thermal expansion and good thermal conductivity, exhibits high compatibility with composite foam materials, effectively mitigating interfacial cracking caused by thermal stress. Simultaneously, its excellent impact resistance and creep resistance contribute to improving the mechanical properties of composite foams and reducing the risk of brittle fracture. Therefore, optimizing the structure of composite foam materials by introducing basalt fiber holds promise for enhancing their stability and reliability in high-end engineering applications. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a basalt fiber reinforced composite foam material and its preparation method. This invention, by adding basalt fiber (BF) to the composite foam material, enhances the mechanical interlocking between the foam and the matrix, improves the mechanical properties of the material, and simultaneously introduces silica, providing an effective heat conduction path for the composite foam material, effectively improving its thermal conductivity. This meets the high-strength structural requirements of composite foam materials and has significant academic value and industrialization prospects.

[0005] This invention is achieved using the following technical solution:

[0006] A method for preparing a basalt fiber reinforced composite foam material includes the following steps:

[0007] (1) Bisphenol A type epoxy resin, methyl hexahydrophthalic anhydride, 2,4,6-tris(dimethylaminomethyl)phenol, and polymethyl methacrylate microspheres were mixed and stirred, and then basalt fiber was added and stirred evenly to obtain a mixture.

[0008] (2) Pour the mixture into a pretreatment mold, then transfer it to a vacuum oven for degassing; then perform curing treatment to obtain basalt fiber reinforced composite foam material;

[0009] The curing process includes a pre-curing stage and a final curing stage; the pre-curing stage involves treating the system at 80°C for 1 hour to allow initial cross-linking; the final curing stage involves curing the system at 100°C for 10 hours to ensure complete curing.

[0010] Preferably, the bisphenol A type epoxy resin has an epoxy value of 0.51 mol / 100g.

[0011] Preferably, the mass ratio of the bisphenol A type epoxy resin, methyl hexahydrophthalic anhydride, 2,4,6-tris(dimethylaminomethyl)phenol, and polymethyl methacrylate microspheres is 100:80:0.5:5.

[0012] Preferably, the mass percentage of basalt fiber in the mixture is 5-15 wt%.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] This invention utilizes the unique porosity bridging of basalt fibers, allowing them to interweave within the foam, effectively ensuring the density and uniformity of the composite foam material structure, reducing porosity connectivity, and minimizing stress concentration, thereby optimizing the load transfer path of the composite foam material. Simultaneously, basalt itself has a high thermal conductivity, which can improve the thermal conductivity of the composite foam material to a certain extent. Compared with traditional composite foam materials, the addition of 15wt% basalt fiber increases the thermal conductivity from 0.065 W / (m·K) to 0.098 W / (m·K), an increase of approximately 50.8%; the flexural modulus increases by approximately 53.1%; and the tensile modulus increases by approximately 50%. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the preferred embodiments of this invention will be described in further detail below with reference to the examples. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0016] Example 1

[0017] 100g of bisphenol A epoxy resin (epoxy value 0.51mol / 100g) was placed in a beaker. 80g of methylhexahydrophthalic anhydride curing agent, 0.5g of DMP-30 curing accelerator, and 5g of PMMA microspheres were added sequentially to the resin. After mixing, the mixture was placed in a planetary stirrer and stirred for 15 minutes. Short-cut basalt fibers were then slowly added, and the mixture was stirred for 40 minutes using a magnetic stirrer. The mixture was then placed in a vacuum oven for degassing treatment for 40 minutes to obtain a mixture. The mass percentage of short-cut basalt fibers in the mixture was 5%.

[0018] After completing the above operations, clean the surface of the metal mold with acetone, then clean it multiple times with deionized water. After the mold surface is dry, apply release wax evenly to the mold surface, pour the mixture into the metal mold, and place it in an oven for staged curing. The staged curing process involves pre-curing at 80℃ for 1 hour, followed by curing at 100℃ for 10 hours, and then demolding after cooling to room temperature to obtain a composite foam material reinforced with chopped basalt fiber.

[0019] Example 2

[0020] 100g of bisphenol A epoxy resin (epoxy value 0.51mol / 100g) was placed in a beaker. 80g of methylhexahydrophthalic anhydride curing agent, 0.5g of DMP-30 curing accelerator, and 5g of PMMA microspheres were added sequentially to the resin. After mixing, the mixture was stirred in a planetary stirrer for 15 minutes. Short-cut basalt fibers were then slowly added, and the mixture was stirred for 40 minutes using a magnetic stirrer. The mixture was then placed in a vacuum oven for degassing treatment for 40 minutes to obtain a mixture. The mass percentage of short-cut basalt fibers in the mixture was 10%.

[0021] After completing the above operations, clean the surface of the metal mold with acetone, then clean it multiple times with deionized water. After the mold surface is dry, apply release wax evenly to the mold surface, pour the mixture into the metal mold, and place it in an oven for staged curing. The staged curing process involves pre-curing at 80℃ for 1 hour, followed by curing at 100℃ for 10 hours, and then demolding after cooling to room temperature to obtain a composite foam material reinforced with chopped basalt fiber.

[0022] Example 3

[0023] 100g of bisphenol A epoxy resin (epoxy value 0.51mol / 100g) was placed in a beaker. 80g of methylhexahydrophthalic anhydride curing agent, 0.5g of DMP-30 curing accelerator, and 5g of PMMA microspheres were added sequentially to the resin. After mixing, the mixture was placed in a planetary stirrer and stirred for 15 minutes. Short-cut basalt fibers were then slowly added, and the mixture was stirred for 40 minutes using a magnetic stirrer. The mixture was then placed in a vacuum oven for degassing treatment for 40 minutes to obtain a mixture. The mass percentage of short-cut basalt fibers in the mixture was 15%.

[0024] After completing the above operations, clean the surface of the metal mold with acetone, then clean it multiple times with deionized water. After the mold surface is dry, apply release wax evenly to the mold surface, pour the mixture into the metal mold, and place it in an oven for staged curing. The staged curing process involves pre-curing at 80℃ for 1 hour, followed by curing at 100℃ for 10 hours, and then demolding after cooling to room temperature to obtain a composite foam material reinforced with chopped basalt fiber.

[0025] Comparative Example 1

[0026] 100g of bisphenol A epoxy resin (epoxy value 0.51mol / 100g) was placed in a beaker. 80g of methylhexahydrophthalic anhydride curing agent, 0.5g of DMP-30 curing accelerator, and 5g of PMMA microspheres were added sequentially to the resin. After mixing, the mixture was stirred in a planetary stirrer for 15 minutes. Subsequently, it was placed in a vacuum oven for degassing treatment for 40 minutes to obtain the final mixture.

[0027] After completing the above operations, clean the surface of the metal mold with acetone, then clean the mold surface multiple times with deionized water. After the mold surface is dry, apply release wax evenly to the mold surface, pour the mixture into the metal mold, and place it in an oven for staged curing. The staged curing process involves first pre-curing at 80℃ for 1 hour, then curing at 100℃ for 10 hours, and finally demolding after cooling to room temperature to obtain a composite foam material.

[0028] The composite foam materials prepared in Examples 1-3 and Comparative Example 1 were tested using the following specific testing methods:

[0029] (1) Tensile modulus test

[0030] Tensile tests were conducted according to GB / T 1447-2005

[26] , with a test speed of 10 mm / min. The specimens were cut into dumbbell strips according to type I.

[0031] The tensile modulus of the composite foam material in Example 1 was 114.5 MPa; the tensile modulus of the composite foam material in Example 2 was 137.4 MPa; the tensile modulus of the composite foam material in Example 3 was 154.8 MPa; and the tensile modulus of the composite foam material in Comparative Example 1 was 103.2 MPa.

[0032] (2) Flexural modulus test

[0033] A three-point bending test was conducted on a 40mm×15mm×1mm sample in accordance with GB / T 1449-2005, and the fracture surface of the sample was observed using a scanning electron microscope.

[0034] The flexural modulus of the composite foam material in Example 1 was 1311.8 MPa; the flexural modulus of the composite foam material in Example 2 was 1697.9 MPa; the flexural modulus of the composite foam material in Example 3 was 1896.4 MPa; and the flexural modulus of the composite foam material in Comparative Example 1 was 1238.6 MPa.

[0035] (3) Thermal conductivity test

[0036] Referring to the ASTM-D5470 international standard for thermal conductivity testing, the sample is first prepared into a flat plate shape. The steady-state heat flow method is used to apply a certain heat flow rate and pressure to the sample, and the thickness of the sample and the temperature difference between the hot and cold plates are tested to obtain the thermal conductivity of the sample. The sample needs to be a relatively large block to obtain a sufficient temperature difference.

[0037] The thermal conductivity of the composite foam material in Example 1 was tested to be 0.069 W / (m·K); the thermal conductivity of the composite foam material in Example 2 was 0.085 W / (m·K); the thermal conductivity of the composite foam material in Example 3 was 0.098 W / (m·K); and the thermal conductivity of the composite foam material in Comparative Example 1 was 0.065 W / (m·K).

[0038] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for preparing a basalt fiber reinforced composite foam material, characterized in that, Includes the following steps: (1) Bisphenol A type epoxy resin, methyl hexahydrophthalic anhydride, 2,4,6-tris(dimethylaminomethyl)phenol, and polymethyl methacrylate microspheres were mixed and stirred, and then basalt fiber was added and stirred evenly to obtain a mixture. (2) Pour the mixture into a pretreatment mold, then transfer it to a vacuum oven for degassing; then perform curing treatment to obtain basalt fiber reinforced composite foam material; The curing process includes a pre-curing stage and a final curing stage; the pre-curing stage involves treating the system at 80°C for 1 hour to allow initial cross-linking; the final curing stage involves curing the system at 100°C for 10 hours to ensure complete curing.

2. The preparation method of the basalt fiber reinforced composite foam material as described in claim 1, characterized in that, The bisphenol A type epoxy resin has an epoxy value of 0.51 mol / 100g.

3. The preparation method of the basalt fiber reinforced composite foam material as described in claim 1, characterized in that, The mass ratio of bisphenol A type epoxy resin, methyl hexahydrophthalic anhydride, 2,4,6-tris(dimethylaminomethyl)phenol, and polymethyl methacrylate microspheres is 100:80:0.5:

5.

4. The preparation method of the basalt fiber reinforced composite foam material as described in claim 1, characterized in that, The basalt fiber in the mixture is 5-15 wt% by mass.

5. A basalt fiber reinforced composite foam material, characterized in that, It is prepared using any one of the methods described in claims 1 to 5.