What is carbon fiber for?

Carbon fiber has the characteristics of light weight, high strength, high modulus, corrosion resistance, electrical conductivity, good shielding performance and high wave absorption, and is mainly used in military industry, aerospace and other high-tech fields. However, with the rapid development of economy, the excellent performance of carbon fiber has been widely used in civil fields.

The main application fields of short carbon fiber include:

1 Reinforced modified plastics: nylon (PA), polypropylene (PP), polycarbonate (PC), phenolic aldehyde (PF), polytetrafluoroethylene (PTFE), polyimide (PI), etc.

2. Building field: carbon fiber reinforced cement, conductive coating, and equivalent antistatic performance;

Electric heating field: conductive paper, electric heating plate, conductive surface felt, needled felt, etc.

4 shielding materials: manufacturing shielding smoke, shielding curtain wall, etc. ;

Thermal insulation materials: carbon fiber reinforced refractory blanks and bricks, carbon fiber reinforced ceramics, etc. ;

New energy field: fuel cell electrodes, etc.

Extended data:

physical features

Carbon fiber has two characteristics: strong tensile strength of carbon material and soft processability of fiber. Its weight is very light, its specific gravity is lighter than that of aluminum, less than 1/4 of steel, and its specific strength is 20 times that of iron. Compared with titanium, steel, aluminum and other metal materials, carbon fiber has the characteristics of high strength, high modulus, low density and small linear expansion coefficient in physical properties, and is called the king of new materials.

chemical property

The chemical properties of carbon fiber are similar to that of carbon, and it has good corrosion resistance to common organic solvents, acids and alkalis, insolubility and swelling, outstanding corrosion resistance, and no rust problem at all. However, it has poor impact resistance and is easy to be damaged. Carbon fiber also has the characteristics of oil resistance, radiation resistance, radiation resistance, absorption of toxic gases, neutron deceleration and so on.

Carbon fiber has many excellent properties, such as high axial strength and modulus, low density, high specific performance, no creep, ultra-high temperature resistance in non-oxidizing environment, good fatigue resistance, small thermal expansion coefficient and anisotropy, good corrosion resistance and good X-ray permeability. Good electrical and thermal conductivity, good electromagnetic shielding, etc.

Compared with traditional glass fiber, the Young's modulus of carbon fiber is more than three times that of traditional glass fiber. Compared with Kevlar fiber, its Young's modulus is about twice that of Kevlar fiber. It is insoluble and swollen in organic solvents, acids and alkalis, and has outstanding corrosion resistance.

In order to obtain good quality carbon fiber, we need to pay attention to the following technical points:

(1) The primary task of preparing high-performance carbon fiber is to realize the high purity, high strength, densification and surface defect-free of precursor. Carbon fiber system engineering needs to start with the polymerization monomer of precursor. The quality of precursor not only determines the properties of carbon fiber, but also restricts its production cost. High-quality polyacrylonitrile precursor is the first prerequisite for manufacturing high-performance carbon fiber. ?

(2) Minimizing impurity defects is the fundamental measure to improve the tensile strength of carbon fiber, and it is also a hot research topic for scientific and technological workers. In a sense, the process of improving strength is essentially the process of reducing and reducing defects.

References:

Baidu encyclopedia-carbon fiber