China Rubber Technology Network provides a platform for rubber technology, natural rubber, rubber price information, rubber training and learning, and rubber material exchange and learning transactions for friends engaged in the rubber industry. We strive to build a rubber technology information exchange platform that rubber people love the most. In the middle of May 2013, at the 9th China Pump Industry and Valve Piping Exhibition held at the Guangzhou Pazhou International Convention and Exhibition Center, a valve expert held a piece of white, soft, air-like elastic body, please identify it. Whether it is fluororubber foamed with foaming agent. After careful observation, it is not foamed fluororubber, but is made of suspension PTFE and some particulate plexiglass materials, and is processed into sheets of different thickness by cold pressing process, and then calcined in a high-temperature furnace. Made into a sponge-like, relatively soft porous PTFE material. It is also possible to add substances such as colloidal alumina to the suspension PTFE, calcinate it in a high-temperature furnace and dissolve the alumina with acid to obtain a porous PTFE material. -China Rubber Net, Natural Rubber, Rubber Price, Rubber Talent Network, Special Rubber, Rubber Products, Rubber Auxiliaries, Rubber Technology Consulting, Rubber Formula, Rubber Forum, Rubber Training, Rubber Testing! Polytetrafluoroethylene [PTFE], commonly known as the king of plastics, is made by homopolymerization or copolymerization of fluorinated monomers. Due to its excellent low friction coefficient, surface inertness and chemical stability, acid and alkali corrosion resistance, strong self-lubricity, but also high and low temperature resistance, non-combustibility and electrical insulation, and a certain mechanical strength, is other materials Not available. In recent years, it has been widely used in industry, high-tech fields and military industry. The production methods of PTFE include suspension method and emulsion method. Uses vary. Emulsion method PTFE is mainly suitable for the molding of paste resin, formulated as an aqueous dispersion, used for spraying, coating, or processing electrical tape, impregnated thin-walled pipes, and waterproof and dustproof fiber materials, and can also be processed into the rubber industry Used release agent and lubricant. The PTFE material made by the suspension method is white powder and has no use value. It is necessary to cold-press the powdered PTFE in the mold to form a blank of a certain shape, and then place it in a high-temperature furnace to sinter the PTFE material of different shapes. For people's needs, various specifications of films, rings, tubes, and cushions are produced on the lathe. The PTFE material on the market is a semi-finished product of PDFE which has been baked. People can buy it back and process it. Rubber Technology Forum, Rubber Technology Consulting, Natural Rubber, Rubber Auxiliaries, Rubber Futures, Rubber Products, Rubber Training, Natural Rubber, Special Rubber, Rubber Talent Network, Rubber Formula, Rubber Recruitment, China Rubber Due to the many special advantages of PTFE, in For rubber products, using its very low friction coefficient and high compression resilience of rubber, PTFE and rubber are bonded together through a special process to achieve high wear resistance, self-lubrication, good sealing, aging resistance, corrosion resistance, and hardness The perfect combination with soft is the development direction of technological innovation of oil seal products today. It is because of the chemical inertness of PTFE that it is very difficult to bond it with rubber materials. People are exploring and researching, making special treatment on PTFE material. The predecessors have made arduous research and development for this, and have studied the surface treatment of sodium naphthalene tetrahydrofuran, strong alkali treatment, flame treatment, plasma treatment, media treatment, high-energy radiation grafting, magnesium-containing liquid ammonia treatment, and laser method, electro-reduction method treatment . However, in terms of application effect and popularity, the sodium naphthalene tetrahydrofuran method is more suitable. The mechanism is: sodium transfers the outermost electrons to the empty orbital of naphthalene to form anion free radicals, and then forms ion pairs with Na, which produces a light green brown complex through reaction, which has strong activity It can carboxylate CO2 to carboxylate and be hydrolyzed into partially saturated ring and alkyl compounds. The single electron in the complex can exist in the ortho and para positions, so it can react with ROH, or RX and CO2. If NBR rubber or other rubber types are bonded together with PTFE to co-vulcanize together. First, we need to prepare PTFE surface treatment liquid. Dissolve sodium and naphthalene in equimolar ratio in tetrahydrofuran [in a special stainless steel reactor with cooling and heat preservation system and nitrogen filling protection and sealed stirring device.] First, enter tetrahydrofuran into the reactor and crush the treated Naphthalene is added under stirring to dissolve it, and then carefully remove the metal sodium that has been cut into small pieces in kerosene to quickly remove the remaining kerosene on the filter paper [because sodium is in the air, it reacts quickly and is flammable, so Store in kerosene, remove from kerosene when used], and then add it carefully until the solution becomes a dark green complex. Note that the temperature must be controlled at about 10 degrees during the reaction. Press this complexing liquid into a dark glass bottle treated with nitrogen with nitrogen, seal it in vacuum and set aside. Remember to avoid sunlight and air. During the entire operation process, pay attention to safety protection to prevent accidents. Then, the PTFE sheet to be processed is pre-cut into a design shape, washed with acetone, dried, or immersed in a spare sodium naphthalene reaction complex solution under continuous nitrogen protection, and continuously stirred. The time is about 30 minutes. Take it out with a camera, wash it with water and acetone, dry it, and put it in a sealed box for cleaning and drying. After so much tossing, the original white PTFE sheet has now turned brown. Then mix it up again, taking NBR glue as an example, first pre-form it for use, and then take out the surface-treated PTFE material from the sealed box with a camera, superimpose it with the rubber material, enter the vulcanizing machine, according to the specified NBR The vulcanization conditions of the adhesive are co-vulcanization. In this way, the composite molding of PTFE and NBR adhesive is completed. It is quite good for sealing products or oil seals and special rubber products. With the innovation and development of the times, the excellent performance of PTFE itself will be widely used in various fields and has become an important part of modern cutting-edge science. In the future, the clothes people wear may be eliminated through the application of fluorine technology, and cars and buildings will no longer be covered with dust and rain. The latex industry’s latex storage tank walls will no longer have gel. , Perfect use, and make greater contributions to mankind!