Preparation method of flexible conductive polyurethane composite film

Abstract

The invention discloses a preparation method of a flexible conductive polyurethane composite film, and belongs to the technical field of composite materials. The method comprises the steps of solvent preparation, membrane casting solution preparation, coagulating bath preparation, membrane casting solution blade coating, phase inversion forming, drying treatment and the like. A ternary mixed solvent prepared by mixing a poor solvent of polyurethane, N,N-dimethylformamide, and a solvent of which the polarity is lower than that of N,N-dimethylformamide is employed, so that the unmodified nano carbon material can be better and uniformly dispersed in the polyurethane solution, original characteristics of the nano carbon material are retained, the polyurethane composite film is endowed with good conductivity, the interfacial compatibility of polyurethane and the nano carbon material is improved, and the mechanical property of the composite film is improved. The prepared flexible conductive polyurethane composite film has good mechanical property and conductive property. The preparation process is simple, can meet the requirements of industrial large-scale production, and has a wide application prospect in the field of flexible conductive materials.

Description

technical field [0001] The invention relates to the technical field of composite materials, in particular to a preparation method of a flexible conductive polyurethane composite film. Background technique [0002] With the increasing demand for wearable devices in society, the research and development of wearable flexible devices has attracted extensive attention, and flexible conductive materials are like blood vessels and nerves in living organisms, which are an indispensable and important part of flexible devices. The electrode materials in traditional devices are mainly metals, but because metals are not flexible, they are prone to fracture and fail during the stretching process, which cannot meet the development needs of flexible devices. Therefore, the research on flexible conductive materials is of great significance. [0003] At present, there are three main types of design ideas for flexible conductive materials: the first type is to design traditional metal materia...

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Problems solved by technology

The electrode material in traditional devices is mainly metal, but because metal is not flexible, it is prone to breakage and failure during stretching, which cannot meet the development needs of flexible devices. Therefore, the research on flexible conductive materials is of great significance

[0003] At present, there are three main types of design ideas for flexible conductive materials: the first type is to design traditional metal materials into stretchable structures through structural design, such as designing metal electrodes such as gold and platinum into fractal structures, so as to be used in flexible sensor devices. , this type of structure has excellent electrical conductivity, but the processing usually requires micromachining methods such as photolithography, electron beam deposition, and reactive ion etching, which are complicated to operate and costly, and are not suitable for large-scale applications; the second type is based on Conductive polymers are used as flexible electrode materials. Commonly used conductive polymers include poly-3-hexylthiophene, polyaniline, polypyrrole, etc. Although conductive polymers have both stretchability and conductivity, they have poor conductivity in practical applications. Poor problem, so the application is limited; the third category is to combine conductive nanomaterials and flexible matrix materials in a certain way to prepare flexible conductive materials, wherein the conductive nanomaterials can choose nanocarbon materials such as carbon nanotubes or graphene, and other There are many types and can be selected flexibly; as a block polymer, polyurethane material has excellent properties such as high elasticity, wear resistance, weather resistance, oil resistance, and grease resistance, and it has various products and simple molding and processing. It is considered to be an excellent flexible material. matrix material; therefore, the combination of conductive nanomaterials and flexible matrix materials has the characteristics of simple method, flexible and diverse raw materials, and easy integration, which is an ideal method for preparing flexible conductive materials

[0004] Based on the small size effect and surface effect of carbon nanotubes, they are prone to agglomeration in the process of preparing composite materials, which limits their effective application range. Therefore, surface modification is usually selected to improve the bonding between carbon nanotubes and matrix materials However, the process of this method is relatively complicated, and the original characteristics of the modified carbon nanotubes are weakened, which improves the conductivity of the prepared high-content conductive composites. Small, which hinders its development and application

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