Overview of radiation-proof fibers
Classification of radiation-proof fibers
1. Radiation resistant fiber -- polyphthalimide fiber) the fiber itself is radiation resistant:
Polyphthalimide fibers were successfully developed in the United States in the 1960s. The macromolecular chains of polyphthalimide fibers are all composed of aromatic rings, and the combination of carbon and oxygen in the aromatic rings is formed by double bonds, which effectively enhance the binding energy. When the radiation line is applied to the polyphthalimide fiber, the radiation energy absorbed by the molecule is far from enough to open the atomic covalent bond in the molecular chain and only converts into heat energy to drain away.
2. Composite radiation-proof fiber, which can be made radiation-resistant by adding other compounds or elements to the fiber:
Through long-term research, people of various synthetic polymer made an evaluation of the resistance to the ability of various kinds of rays, determine the use of all kinds of high polymer in radiation environment limit and radiation resistance, polyethylene, polypropylene, polystyrene, polycarbonate, polyester, polyvinyl chloride (PVC) with excellent resistance to radiation and spinnability, both can be used as a melt spinning the basic polymer composite anti-radiation fiber manufacture. The radiation protection agent added by the composite radiation protection fiber includes heavy elements and elements with large absorption cross sections and their compounds. Heavy elements block neutrons, while elements with large cross sections block fast neutrons and absorb slow neutrons without releasing V rays.
As a kind of ionizing radiation, X-ray has been successfully applied in material X-ray flaw detection, human X-ray fluoroscopy and X-ray analysis. Staff long-term exposure to X-ray, gonads, mammary glands, hematopoietic bone marrow will produce damage, more than the dose of cancer will even bring serious threats to the human body.
In the 1980s, the textile materials research institute of the former Soviet union and the nuclear research institute jointly developed the acrylic ray-proof fiber. The method is to modify the acrylic fiber, then impregnate it with lead acetate solution, and get the acrylic fiber fabric which is covalently bonded and grafted with lead metal. The fabric made by this method can significantly reduce the intensity of X-ray radiation. If compound additives such as lead, uranium and lutetium are used, the protection against X-ray can be further improved.
Japan's shinshin chemical and Austria's Lenzing added barium sulfate to the viscose fiber, making it a radiation-proof fiber that can be used to make clothing for workers who have been exposed to x-rays for a long time, with good results.
Demron fabric, a radiation-protection technology company in Florida, USA, has modified polyethylene and polyvinyl chloride with radiation-protection technology. It consists of a layer of polyethylene and polyvinyl chloride polymer sandwiched between two layers of ordinary woven fabric. It protects against not only x-rays but also V rays.
The research of tianjin university of technology in China has found that the fabric made of anti-x-ray fiber by laminating or adding adhesive containing shielding agent to the fabric after hot pressing is a good material to prevent X-ray radiation.
(2) neutron-proof radiation fiber
In 1983 Japan toray company developed the neutron radiation shield with composite spinning method of composite fiber, neutron absorption material and high polymer in the kneading machine melt blend as a core layer component, pure polymer melt for cortex compound spinning, the fiber of skin-core structure, dry or damp and hot tensile system must have a certain strength of fiber.
Tianjin university of technology has successfully developed neutron-proof radiation fibers. This kind of fiber also USES the skin core composite structure to spin the composite fiber. A powder containing a coupling agent and a neutron absorbing substance.
3. Conductive absorbing fiber -- anti-electromagnetic radiation fiber,
Electromagnetic radiation refers to electromagnetic radiation in the microwave segment, radio frequency segment and working frequency band. As non-ionizing radiation, this kind of radiation is harmful to human body through accumulation effect. Anti electromagnetic radiation shielding mechanism of fiber is not as preventing X-ray and neutron radiation prevention fiber is given priority to with absorption, but with low resistance conductive material reflection effect on electromagnetic radiation, to produce contrary to the original electromagnetic radiation in the conductor of electric current and magnetic pole, and form a shield space, thus weakening external electromagnetic radiation hazards. To sum up, there are the following methods:
Weave the wire and yarn together
Mitsubishi rayon USES polyester yarn or cotton-polyester blended yarn and high purity extremely fine anti-oxidation copper wire woven together with special composite technology to develop composite shielding fabrics that not only shield well, but also wash well, and can be routinely dyed and sewn.
The metal fibers are spun into the yarn
This is the main material that prevents electromagnetic radiate textile at present, use metallic fiber to have copper fiber, iron fiber and stainless steel fiber. Among them stainless steel fiber synthesis can be the best.
Use metallized fiber
A metallized fiber is a fiber with a conductive film formed by coating or coating on the surface.
(4) develop bulk conductive monomers and polymers
Conjugated polymers with bulk conductivity, such as polyethylene, polyaniline and polyheterocyclic polymers, are chemically doped with ASP3, I2 and BF3.
-- from guangxi light industry, wei wei. Research on radiation-proof fiber