阅读说明：本技术 一种高效隔热的碳纤维复合材料 (Efficient heat-insulation carbon fiber composite material ) 是由 严兵 赵清新 郎鸣华 刘成 何定军 于洋 张林强 刘圣强 刘腾达 郭海军 于 2019-09-23 设计创作，主要内容包括：本发明提供一种碳纤维复合材料,包括相变储能层和位于相变储能层两侧的表面层,且相变储能层中含有碳纤维和相变储能材料,相变储能材料的熔融焓大于100J/g。本发明利用相变储能材料的相变储能能力,通过合理的层和配方设计制备成碳纤维复合材料。具有优异的耐高温性能和隔热性能,可以在260℃以上长期使用。所得的复合材料不仅质轻,还大大降低了隔热材料的使用成本。(The invention provides a carbon fiber composite material which comprises a phase change energy storage layer and surface layers positioned on two sides of the phase change energy storage layer, wherein the phase change energy storage layer contains carbon fibers and a phase change energy storage material, and the melting enthalpy of the phase change energy storage material is more than 100J/g. The invention utilizes the phase-change energy storage capacity of the phase-change energy storage material to prepare the carbon fiber composite material through reasonable layer and formula design. Has excellent high temperature resistance and heat insulation performance, and can be used for a long time at the temperature of more than 260 ℃. The obtained composite material is light in weight, and the use cost of the heat insulation material is greatly reduced.)

1. The carbon fiber composite material is characterized by comprising a phase change energy storage layer and surface layers positioned on two sides of the phase change energy storage layer, wherein the phase change energy storage layer contains carbon fibers and a phase change energy storage material, and the melting enthalpy of the phase change energy storage material is greater than 100J/g.

2. The carbon fiber composite material as claimed in claim 1, wherein the phase change energy storage layer contains a matrix resin having a melting point higher than 260 ℃.

3. The carbon fiber composite material according to claim 1 or 2, wherein the matrix resin is one or both of polyether ether ketone and polyphenylene sulfide.

4. The carbon fiber composite material as claimed in claim 1, wherein the phase change energy storage material comprises a first phase change energy storage material having a melting point of 60-160 ℃ and a second phase change energy storage material having a melting point of 161-260 ℃.

5. The carbon fiber composite material as claimed in claim 4, wherein the melting enthalpy ratio of the first phase change energy storage material and the second phase change energy storage material in the phase change energy storage layer is 1: 2-1: 4.

6. The carbon fiber composite material as claimed in claim 5, wherein the sum of the melting enthalpies of the first phase change energy storage material and the second phase change energy storage material is 200J/g or more in the phase change energy storage layer at 30-260 ℃.

7. The carbon fiber composite material as claimed in claim 1, wherein the surface layer contains carbon fibers and a matrix resin having a melting point higher than 260 ℃.

8. The carbon fiber composite material as claimed in claim 1, wherein the thickness ratio of the phase change energy storage layer to the surface layer on either side is 1: 1-1: 0.1.

9. An article made of the carbon fiber composite material according to any one of claims 1 to 8.

10. Use of an article made of carbon fiber composite material according to claim 9 in transportation vehicles, power generation equipment, sports equipment, medical equipment.

Technical Field

The invention relates to the field of composite materials, in particular to a carbon fiber composite material.

Background

The heat insulating material is a material capable of retarding heat flow transmission, and is also called a heat insulating material. The heat insulating material includes porous material, vacuum material, heat reflecting material, etc. The porous material utilizes the pores contained in the material to insulate heat, and the principle is that the heat conductivity coefficient of air or inert gas in the pores is very low; the vacuum insulation material is insulated by blocking convection by using internal vacuum of the material. However, these two materials have insufficient mechanical strength due to a large number of voids in the matrix, and are not suitable for the field requiring high strength. The heat reflection material has high reflection coefficient and can reflect heat, such as gold, silver, nickel, aluminum foil or metal-plated polyester, polyimide film and the like, and the material can be suitable for the field needing high strength by selecting a proper base material, but metal substances are easy to oxidize, and the reflection capacity is weakened due to oxidation, so the material is not beneficial to long-time use.

The carbon fiber is a new material with high temperature resistance and excellent mechanical property, has the soft processability of textile fiber, and is a preferred material for preparing high-temperature heat-insulating composite materials. CN201711094987.8 provides a modified carbon fiber heat insulation composite material with a porous structure, which is prepared from raw materials such as silicon powder, coconut shells, phenol, polyvinyl alcohol and the like. CN 201811580692.6 provides an engine heat insulation structure for oil moves unmanned aerial vehicle, including set up respectively in the front and back side of engine first heat insulating board and second heat insulating board, first heat insulating board and second heat insulating board by porous carbon fiber backup pad and the intermediate layer laminating is in thermal-insulated cotton on the carbon fiber backup pad constitutes. The above method has improved mechanical strength compared with other porous heat insulating materials due to the introduction of carbon fibers in the system, but the comprehensive performance of the above materials is still insufficient in application fields such as engines, rockets, airplanes, boilers and the like which have high requirements for heat insulating property and strength.

In summary, the prior art does not provide a carbon fiber composite material with excellent thermal insulation performance and mechanical performance.

Disclosure of Invention

In order to solve the problems, the invention provides a carbon fiber composite material which comprises a phase change energy storage layer and surface layers positioned on two sides of the phase change energy storage layer, wherein the phase change energy storage layer contains carbon fibers and a phase change energy storage material with melting enthalpy more than 100J/g.

The phase change energy storage layer is the key of the heat insulation effect in the carbon fiber composite material, and also plays a role in improving the heat resistance and bearing partial mechanical strength.

The carbon fiber is a fibrous material prepared from polyacrylonitrile, asphalt, phenolic aldehyde, viscose and other raw materials through spinning, oxidation, carbonization and sizing. The carbon fibers may be one or more of carbon fiber filaments, chopped carbon fibers, carbon paper, and the like. In the phase change energy storage layer, carbon fibers are used as reinforcing materials. In view of the convenience of the post-forming process, it is preferable that the carbon fiber is carbon paper. The carbon paper is manufactured by a dry method, carbon fibers are uniformly dispersed in slurry, and a proper amount of unsaturated resin is added to serve as an adhesive. Wherein, the carbon fiber is distributed evenly, and the strength performance of the finished paper is better.

The phase-change energy storage material is a material with high melting enthalpy, and can convert external heat into phase-change heat for storage, thereby achieving the effect of heat insulation. The solid-liquid phase change and the liquid-gas phase change can store heat, and in consideration of practicability, the phase change energy storage material stores heat by utilizing melting enthalpy in the solid-liquid phase change.

The size of the melting enthalpy influences the energy storage effect of the phase-change energy storage material. The larger the melting enthalpy is, the better the energy storage effect of the phase change energy storage material is. In the invention, the phase-change energy storage material has a melting enthalpy of more than 100J/g, preferably more than 150J/g.

The phase change energy storage layer of the carbon fiber composite material also contains matrix resin, and the melting point of the matrix resin is higher than 260 ℃.

The matrix resin plays a role in bonding carbon fibers, storing phase change energy storage materials and providing mechanical property and heat resistance. The polymer with higher melting point can effectively improve the heat resistance and expand the application field of the carbon fiber composite material. The matrix resin may be one or more of polyether ether ketone, polyphenylene sulfide, liquid crystal polymer, cured epoxy resin, cured bismaleimide resin, polyimide, aromatic polyamide, and the like. In view of convenience and effectiveness of the preparation process, the matrix resin is preferably one or both of polyether ether ketone and polyphenylene sulfide.

Polyetheretherketone is a linear aromatic polymer compound having the following structural unit in the main chain, is a crystalline thermoplastic, has a glass transition temperature of about 143 ℃ and a melting point of about 343 ℃, and can reach a long-term use temperature of 260 ℃.

Polyphenylene Sulfide (PPS) is a special engineering plastic with a molecular main chain containing the following structural units, has a melting point of about 280 ℃, has excellent physical and chemical properties, and has the characteristics of high mechanical strength, high temperature resistance, high flame retardance, strong chemical resistance, radiation resistance, high hardness, good thermal stability, excellent electrical properties and the like.

In order to better improve the heat insulation effect of the carbon fiber composite material, in the phase change energy storage layer, preferably, the phase change energy storage material comprises a first phase change energy storage material with a melting point of 60-160 ℃ and a second phase change energy storage material with a melting point of 161-260 ℃. Having these two energy storage materials has the following effects: the carbon fiber composite material has a heat insulation effect at a lower temperature, or can absorb a large amount of heat at a higher temperature.

In consideration of the application field of the carbon fiber composite material of the invention needing to have higher temperature, the melting enthalpy ratio of the first phase-change energy storage material and the second phase-change energy storage material in the phase-change energy storage layer is preferably 1: 2-1: 4. The inventor finds that if the melting enthalpy of the first phase-change energy storage material is too high, the absorption of heat at high temperature is not facilitated, and the heat insulation temperature is lower; if the melting enthalpy of the first phase change energy storage material is too low, on the one hand, the heat insulation effect of the material at a lower temperature is reduced. On the other hand, when the carbon fiber composite material is subjected to high temperature, the temperature of the material is increased too fast because the phase change temperature region of the first phase change energy storage material cannot effectively insulate heat, and the application field requiring the temperature to rise smoothly is not facilitated. Preferably, the melting enthalpy ratio of the first phase-change energy storage material to the second phase-change energy storage material is 1: 2.5-1: 3.5.

The melting enthalpy of the phase-change energy storage layer directly influences the heat insulation effect of the composite material, so the sum of the melting enthalpies of the phase-change energy storage layer at 30-260 ℃ is preferably more than 200J/g, and more preferably more than 250J/g. The melting enthalpy is the sum of melting enthalpies obtained by measuring the phase change energy storage layer through a Differential Scanning Calorimeter (DSC).

In the carbon fiber composite material, the surface layers positioned at the two sides of the phase change energy storage layer provide heat resistance for the carbon fiber composite material and bear partial mechanical strength.

The surface layer contains carbon fiber and matrix resin with melting point higher than 260 ℃, and the matrix resin can be one or more of polyether ether ketone, polyphenylene sulfide, liquid crystal polymer, epoxy resin cured product, bismaleimide resin cured product, polyimide, aromatic polyamide and the like. The carbon fiber and the matrix resin can be the same as or different from the carbon fiber and the matrix resin in the phase-change energy storage layer respectively. In view of the fact that the same raw material can be used to greatly reduce the cost, it is preferable to use the same carbon fibers and matrix resin in the surface layer and the phase change energy storage layer.

Preferably, the thickness ratio of the phase change energy storage layer to the surface layers on any side is 1: 1-1: 0.1. The surface layer is too thick, so that the weight and the price of the carbon fiber composite material can be improved; the surface layer is too thin, which is not favorable for the heat resistance of the carbon fiber composite material, and the mechanical strength may be too low.

The invention also provides a product made of the carbon fiber composite material.

The invention also provides the application of the product in traffic vehicles, power generation equipment, sports equipment and medical equipment.

The effects and the application of the invention are as follows:

the invention utilizes the phase-change energy storage capacity of the phase-change energy storage material to prepare the carbon fiber composite material through reasonable layer and formula design. Has excellent high temperature resistance and heat insulation performance, and can be used for a long time at the temperature of more than 260 ℃. The obtained composite material is light in weight, and the use cost of the heat insulation material is greatly reduced.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

The parameters and the measuring method thereof related to the embodiment and the comparative example are as follows:

surface gram weight: a10 cm × 10cm sample was cut out and weighed. The areal weight is the weight per area.

Melting point and enthalpy of fusion: the sample is heated from 25 ℃ to 400 ℃ at a temperature of 10 ℃/min by using DSC measurement and a nitrogen atmosphere, the peak value of each melting peak in the heating process is measured as each melting point of the sample, and the sum of the areas of each melting peak at 30-260 ℃ is used as the melting enthalpy of the sample.

Heat resistance temperature: the samples were subjected to a Martin Heat resistance test in air. The temperature rise speed is 50 ℃/h, and the bending stress of the standard sample is 50kg/cm²And (3) bending the sample strip, wherein the temperature corresponding to the reading in the indicator reduced by 6mm is the Martin heat-resistant temperature, namely the heat-resistant temperature.

Heat insulation: the samples were prepared into test pieces each having a length and a width of 10 cm. The lower platen of a die press was heated to 260 c and the sample was placed on the lower platen. After 2 hours, the temperature of the test upper surface was measured. The lower the temperature, the better the heat resistance.

Thickness: the measurement is made with a vernier caliper to the nearest 0.1 mm.