epoxy resin
DATE：2022/7/8 8:59:27 / READ： / SOURCE：This station
epoxy resin
Epoxy resin (EP) is a kind of tree egg with epoxy group in its molecular structure. There are many kinds of such resins, but the most important one is the ring resin synthesized by bisphenol A and epichlorohydrin. Epoxy resin is mainly made into liquid products with different viscosities, and can also be made into solidified products. This is caused by different relative molecular weights. The difference of relative molecular weight of epoxy resin is characterized by epoxy value. The larger the relative molecular weight is, the smaller the epoxy value is. Lithium battery diaphragm production line www.handern comEpoxy resin has the following properties: ① the cured product of epoxy resin has good dimensional stability, low curing shrinkage, usually less than 1%, and good aging resistance. (2) epoxy resin can be used continuously at 135 ℃, and its reinforcing resin can be used continuously at 260 ℃, with high mechanical strength and good impact performance. ③ epoxy resin has excellent bonding performance, and the bonding force is usually higher than the strength of the resin itself.
④ The cured epoxy resin has excellent dielectric properties and chemical resistance, and can maintain excellent mechanical properties under the action of many chemical reagents. Low temperature resistance is good, and the shrinkage is the smallest at -60 ℃. Epoxy resin can be laminated, molded, injected, cast and wound. It can be used as foamed plastics, reinforced plastics, adhesives, coatings, etc. Epoxy resin can be crosslinked to form a network structure and cured under the action of amines, acids and other substances. No low molecular substances are discharged during the curing process, so the products can be formed under low pressure, with low shrinkage and not easy to produce pores, which are important characteristics of epoxy resin. Epoxy resin has strong adhesion and can be cured at low temperature and low pressure, so it is widely used in adhesives. Epoxy FRP products reinforced with glass fiber and its fabric have outstanding mechanical properties and electrical insulation properties. The main products include electrical switchgear, instrument panels, printed circuit boards, pressure vessels, chemical pipelines, mechanical parts, etc. Epoxy adhesive, commonly known as all-purpose adhesive, can bond various metal and non-metal materials.
Epoxy foamed plastics can be prepared by chemical foaming, physical foaming and curing with glass, ceramic or plastic hollow microspheres. The raw materials used include liquid epoxy resin, surfactant and foaming agent. Epoxy foam can be made into thermal insulation materials, sound-absorbing materials, sandwich materials, floating materials, etc. Lithium battery diaphragm production line www.handern com
Unsaturated polyester (up) refers to a thermosetting resin with body structure obtained by esterification of mixed acid composed of unsaturated dicarboxylic acid and partially saturated dicarboxylic acid with diols (ethylene glycol, propylene glycol) to form linear polyester, which is then crosslinked and cured with polymerizable olefin monomers (such as styrene). Unsaturated polyester is a kind of thermosetting resin. After crosslinking and curing with polystyrene, it has high hardness, excellent heat resistance, electrical properties, water resistance and weather resistance, and can withstand all chemicals except strong acids, bases, ketones and chlorinated hydrocarbon solvents. 70% to 80% of unsaturated polyester is used to make FRP, and the manufacturing methods include casting method, mechanical mixing glass fiber method, spray molding, sheet molding (SMC) and integral molding (BMC), etc. Polyester glass fiber reinforced plastic has excellent tensile strength and impact toughness. It is used to manufacture aircraft parts, car shells, train carriages and small boats. It is used to manufacture transparent corrugated boards, artificial marble and roof truss materials in buildings. It can also be used as chemical equipment and pipelines, as well as electrical insulation materials. Unsaturated polyester foam has good mechanical properties, high surface wear resistance, good cold resistance (-140 ℃) and heat resistance. It can be used for the core materials of building sandwich panels, decorative signs, furniture parts, etc. Lithium battery diaphragm production line www.handern com
Polytetrafluoroethylene (PTFE) is a fluoroplastic with excellent cold resistance and chemical resistance, excellent dielectric properties and self-lubricating properties. It has the lowest friction coefficient among known materials at present, and has the characteristics of anti adhesion, anti pollution and non aging.
Polytetrafluoroethylene is a nonpolar straight chain crystalline polymer, with a general crystallinity of 55%~75% and an appearance of milky white wax. Even at high temperature, strong acid, strong alkali and strong oxidant have no effect on it. It is only corroded by molten alkali metals, and its corrosion resistance is even higher than that of precious metals. General organic solvents do not work on it. In addition, polytetrafluoroethylene is not affected by oxygen and ultraviolet rays. It is non absorbent, extremely weather resistant, and non combustible. See the table for the properties of polytetrafluoroethylene. Polytetrafluoroethylene is a thermoplastic. Because of its high melting point (327 ℃) and decomposition temperature (415 ℃), and its high viscosity at high temperature, it cannot be in a flowing state, so it is difficult to form and process. Generally, products are processed by powder cold pressing sintering process, and products such as films, plastic parts, fibers and coatings can also be made by extrusion, calendering, threading, spraying and other molding processes. Polytetrafluoroethylene has good machinability. Polytetrafluoroethylene products are widely used in industrial departments such as electrical appliances and electronics, chemical industry, aviation and machinery, and defense departments with cutting-edge technologies such as rockets, missiles and aerospace. Polytetrafluoroethylene foam is generally used for filter cloth, filter paper, microporous glass
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