Polycarbonate synthesis There are two ways, one is phosgene, the second is the transesterification method. Phosgene method: phosgene method known as solvent and interfacial polycondensation. It is at room temperature and atmospheric pressure, using the sodium salt of bisphenol A and phosgene by interfacial polycondensation of the polycarbonate. Phosgene production process mainly consists of the following steps: phosgenation. The prepared bisphenol salt added phosgenation reactor, followed by the addition of methylene chloride in the phosgenation reactor, stirring was started when the kettle temperature dropped to 20 ℃, constant speed leads to phosgene phosgenated . When the pH of the reaction medium is 7-8, phosgene was stopped, polyurethane pu tube, phosgenation ends. Condensation. The phosgenation was 25% alkali catalyst, trimethyl benzyl ammonium chloride and phenol, a molecular weight modifier added to the reaction kettle, pu tube, with stirring, the reaction was continued at 25-30 ℃ 3-4h The reaction is exothermic, it should be used cold water to cool. After termination of the reaction, standing layered alkali salt solution to remove the upper layer, then add 5% formic acid and to slightly acidic material, pu, acidic water phase separation of the upper, pu hose, after neutralizing the reaction solution and then processed . - The crown Plastic Products Co., Ltd. of Dongguan City, the crown Plastic Products Co., Ltd. is a private enterprise, located in Hengli Town, Dongguan City, Metro Industrial Park eastern ring road. The company's main products for all types of plastic products manufacturing. Our products are widely used in communications, electronics, electrical, medicine, agriculture, industry, landscape irrigation and other industries. The company has advanced high-performance extruder. In the production of plastic products, we specialize in the manufacture of plastic pipe products difficult, with the company unique production process. Companies to technology, quality products and quality service to serve the customer. Providing customers with a range of quality support services. We won the majority of domestic and foreign customers trust and support. pu polyether pipes | quality pu tube Supply (Online) | pu provided by the Dongguan City, the crown plastic products Limited. Dongguan City, the crown Plastic Products Co., Ltd. (www.gddgyg.com) Dongguan, Guangdong, wire, tube, leader board manufacturing equipment, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum meet customer needs. Plastic pipe crown in the leadership with the staff warmly welcome all inquiries negotiations to create the crown Plastic pipe a better future.