use
Although the radiation stability of organic silicone rubber is not very high, it has good heat resistance, so it is widely used in some occasions where the radiation intensity is relatively not high and the temperature is high. Such as vulcanized silicone rubber and tungsten powder can be obtained elastic, heat stable shielding materials for gamma radiation. As a composite shielding material of binder and neutron moderator, polyethylene is limited by its low thermal stability, and can only be replaced by organosilicone rubber with less hydrogen for higher temperatures (>150 ° C).
As a high temperature sealing material, organic silicone rubber gaskets can also be used on irradiation devices and in-pile test devices. Silicone rubber has good compatibility with human body and has been widely used in the field of nuclear medicine, such as connecting tubes, human organs and drug coating. The use of radiation vulcanized silicone rubber can improve the tearing strength and prepare the core parts. As a radiation processing raw material, radiation vulcanized polyheterosiloxane has high heat resistance, no air, short-term use up to 560~620℃.
practical value
Silicone rubber has outstanding moisture-proof and mildew proof ability, and the cured body has the characteristics of large elasticity and small shrinkage rate, which is a good anti-vibration body. The multi-waveform pulse transformer for guidance radar is a kind of high frequency, low loss, high potential, high power and multi-waveform device with operating potential greater than 30kV. The core is made of U512 platinum molybdenum alloy and coil amorphous alloy with thickness of 0.02~0.03mm. Because these two kinds of magnetic cores are extremely brittle and annular, in order to prevent the deterioration of the magnetic core performance, they are installed in the protective box, and the room temperature vulcanized silicone rubber is vacuum injected into the box body. The protection box and the magnetic core become a whole, which can effectively prevent the damage caused by vibration, and also effectively solve the problem of winding insulation to the ground. Due to the thick adhesive layer, the use temperature exceeds 130 ° C, the box is sealed, in order to ensure that there is no longer a low molecular matter escape during the use of the vulcanized polymer after a long time to avoid the phenomenon of self-hydrolysis into a viscous body, the use of dry, hot flash, dry three-stage vulcanization process. That is, it is first dried at room temperature, then processed in a humid box with a relative humidity of more than 90% at 40~50 ° C, and then dried in an oven at 120~200 ° C, so that the active groups can fully react and the generated low molecular matter can be completely removed to ensure the stable performance of the potting body. There are four feed support tubes with a length of about 800mm, three of which run through the feeder waveguide. After the product parameters are adjusted, the inlet and outlet of the support pipe at both ends only leaves a long and narrow cavity of 2~3mm wide. In order to ensure the normal operation of the antenna, prevent the damage caused by the vibration of azimuth pitching and rotating operation, and prevent the erosion of rain, wind sand, dust and salt spray, organic silicone rubber is used to fill the supporting casing cavity and seal the port. The gap between the inner wall of the support tube and the waveguide is narrow and long, and the silicone rubber is viscous and not easy to flow, which is the key problem to be solved in the potting process. The organic silicone rubber used is a two-component adhesive, consisting of a base material, a filler, a treatment agent and a vulcanizing agent.