Use | Applications for the manufacture of high-temperature insulation seals, medical materials, high-voltage cables, adhesives, precision molds, such as Isolation glue |
WGK Germany | 3 |
RTECS | TQ2700000 |
introduction
NHS biotin reagents can perform simple and effective biotin labeling of antibodies, proteins and any other macromolecules containing primary amines in the solution. The three reagents differ only in the length of the spacer arm, providing researchers with the possibility of optimizing labeling and detection experiments, of which the steric hindrance of biotin binding is an important factor.
application
NHS biotin reagents can perform simple and effective biotin labeling of antibodies, proteins and any other macromolecules containing primary amines in the solution. The three reagents differ only in the length of the spacer arm, providing researchers with the possibility of optimizing labeling and detection experiments, of which the steric hindrance of biotin binding is an important factor.
overview
Silicone rubber (Silicone rubbers) is a synthetic rubber and semi-inorganic polymer elastic material with a silicon-oxygen structure in the molecular main chain. It is formed by hydrolysis of bifunctional silicone monomers such as dimethyldichlorosilane and polycondensation.
Silicone rubber looks like ordinary rubber in appearance, but silicone rubber has a high degree of thermal stability and elasticity. Maintain the original characteristics in the range of -60~300 ℃. When compressed at high temperature, the shrinkage is very small, and the external force is restored to its original state. Silicone rubber is divided into hot vulcanization type and room temperature vulcanization type according to vulcanization method, the latter develops faster.
Silicone rubber has defects such as low molecular polarity, strong hydrophobicity and poor physical properties, so its modification research is currently a hot research topic.
in order to meet the needs of special purposes, silicone rubber with special properties, such as conductive silicone rubber, thermal conductive silicone rubber, heat-resistant rubber, oil-resistant silicone rubber, shielding silicone rubber, flame retardant silicone rubber, damping silicone rubber, insulating silicone rubber and sponge silicone rubber, etc.
classification
Silicone rubber can be divided into heat vulcanization (HTV) silicone rubber and room temperature vulcanization (RTV) silicone rubber according to its vulcanization characteristics
1.HTV Silicone Rubber
HTV silicone rubber (also known as high temperature vulcanized silicone rubber) is a kind of silicone rubber with large output and wide application. It can be divided into methyl silicone rubber, dimethyl vinyl silicone rubber, methyl vinyl phenyl silicone rubber, nitrile silicone rubber and fluorosilicone rubber. HTV silicone rubber has excellent high and low temperature resistance, physiological inertness, electrical insulation, ozone resistance, weathering resistance, hydrophobicity and moisture resistance.
2.RTV Silicone Rubber
RTV silicone rubber is a kind of silicone rubber with end groups containing hydroxyl or acetoxy groups. Its Mr is low, usually a viscous flow, and can be cured at room temperature. It is divided into one-component RTV silicone rubber and two-component RTV silicone rubber. Fully vulcanized products have good heat resistance, cold resistance and dielectric properties, but their mechanical strength is low, and they can be used for casting and coating adhesives.
Production
Silicone rubber is divided into hot vulcanization type and room temperature vulcanization type according to vulcanization method, and the latter develops rapidly.
room temperature vulcanized silicone rubber is a blend of polydimethylsiloxane and polymethylethoxy siloxane containing hydroxyl groups. without adding a cross-linking agent, it can be cured into elastic silicone rubber after adding 1% ~ 15% catalyst (such as dibutyldilaurate tin) at room temperature for 4~24 hours.
The preparation method of heating silicone rubber is: mixing fine powdered silica gel and other fillers into linear dimethylpolysiloxane with larger molecular weight, and then treating with benzoyl peroxide. When dimethylpolysiloxane is treated with peroxide, the methyl group loses hydrogen atoms and generates carbon radicals, which are crosslinked through free radical coupling. Due to the small attraction between silicone molecules, vulcanized silicone rubber without filler has very small tensile strength. In order to obtain silicone rubber with practical strength, fillers with strong affinity for silicon molecules need to be added for reinforcement.
modified
The modification methods are mainly divided into physical modification and chemical modification.
Chemical modification: The methods used and the good effect on the physical and mechanical properties of the polymer are limited.
physical modification: mainly includes blending modification and filling modification with other polymers. Blending modification is beneficial to supplement the deficiency of single component. At present, blending modification of rubber materials is an effective method to improve the deficiency of single material performance. Filling modification can improve the physical and mechanical energy of polymers to some extent, reduce the cost of raw materials, or give materials new functions. Both blending modification and filling modification have the advantages of simple and flexible methods.
use
living use: it can be used as protective layer of wires, cables, metal parts, heat insulation protective coating, gasket seals, shockproof parts, etc.
Sealing products: Sealing products include automobile engine crankshaft rear sealing ring, fuel pump seal, air conditioning compressor seal, potentiometer insulation bushing and potting materials.
Medical equipment: Using its physiological inert, non-toxic, and non-allergic characteristics, it can be used as an ideal medical polymer material to manufacture artificial heart valves, artificial lungs, artificial esophagus and surgical materials.
References
[1] Wang Daquan, editor-in-chief. Dictionary of Fine Chemical Industry. Beijing: Chemical Industry Press. 1998. p. 246.
[2] Wu Shimin, editor-in-chief of Yin Delin. Concise and Refined Dictionary of the University of Technology. Shenyang: Liaoning Science and Technology Press. 1999.
[3] Yuan Yunkai, edited by Gu Mingyuan. Science and Technology Social Dictionary • Chemistry. Hangzhou: Zhejiang Education Press. 1992.
[4] Wang Xiangai, Zhang Hongli. Research Progress of Silicone Rubber [J]. China Adhesive, 2012,09:44-48.
[5] Tu Ting, Chen Fulin, Cen Lan, Zhou Yanhao. Research Progress in Physical Modification of Silicone Rubber [J]. Elastomer, 2010,02:77-82.
[6] Editor-in-Chief An Jiaju; Bao Wenchu, Wang Boying, and Li Shunping. Practical fine chemical dictionary. Beijing: China Light Industry Press