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Semelhante a Polytetrafluoroethylene.pptx
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Polytetrafluoroethylene.pptx
- 2. PTFE Overview Polytetrafluoroethylene (PTFE), commonly known as Teflon, is a fluoropolymer made of tetrafluoroethylene (TFE) monomer. It is widely used compound in our life The PTFE Origin Story In 1938, Roy Plunkett, discovered PTFE when trying to create a new chlorofluorocarbon refrigerant He stored the TFE gas in metal cans and he used the weight of the cans to measure the amount of TFE used although the weight of the gas pressure bottle didn’t signal that it was empty, no gas flowed out of it . he decided to cut the metal can apart. he found a white and flaky powder on the interior of the can . The TFE had polymerized overnight with the iron from the inside of the can acting as a catalyst.
- 4. PTFE market 52 % Asia pacific Rest of the world Market size is expected to grow faster next decade 6.5 % 2030 $5.1 Billion $3.4 Billion 2022 projected to reach a revised size of US$5.1 Billion by 2030 2022-2030
- 5. Preparation of monomer 1.Chloroform (trichloomethane) by reacting methane with a mixture of hydrogen chloride and chlorine. CH4(g) + 3Cl2(g) –> CHCl3(g) + 3HCl(g) 2.chlorodifluoromethane By reacting chloroform with anhydrous hydrogen fluoride, chlorodifluoromethane is created. CHCl3(g) + 2HF(g) –> CHCIF2(g) + 2HCl(g) 3. tetrafluoroethylene TFE BY Heating chlorodifluoromethane in the absence of air, a process known as pyrolysis 2CHClF2(g) –> C2F4(g) + 2HCl(g) 03 01 02
- 7. Process safety constructions for preparation of monomer 1. TFE is highly flammable, and its transportation is very risky. Therefore, this step must be performed on-site where the final product (PTFE) is created TFE must be cooled rapidly to avoid reverse reaction and explosive decomposition. TFE is highly explosive, it is produced on- site, when and where the polymerization will occur, minimizing storage time. Purification of TFE : Pure monomer is required for polymerization. The gas is first scrubbed to remove any hydrochloric acid and then distilled to separate other impurities
- 9. PTFE is prepared by Radical Polymerization of TFE Consists of three steps 1] Initiation step: *it is Used proxy disulfuric acid (reagent) which will be decompose homologically by heating into two free radicals. *These radicals used as a radical initiator in the polymerization process.
- 10. *The radical open the double bond of TFE and create a new radical. *This new radical open another TFE monomer and create a new monomer and so on.
- 11. 2] Propagation Step: *This process continues making the actual polymer PTFE. *at this step the polymer chain was created.
- 12. Termination Step: At this step the last radical in a polymer chain connected with the last radical in another polymer chain to produce the PTFE.
- 13. Polymerization of TFE two well-known main methods of producing PTFE: 1 suspension polymerization creates grains of PTFE that can be processed into pellets which can be molded 2 dispersion polymerization produces PTFE in the form of a milky paste that can be processed into a fine powder. useful for coatings • The reaction chamber is filled with purified water and a reaction agent or initiator, terminator • The liquid TFE is piped into the reaction chamber. As the TFE meets the initiator, it begins to polymerize. The resulting PTFE forms solid grains that float to the surface heat, produced so the chamber is cooled by the circulation of cold water or another coolant in a jacket PROCESS DESCRIBTION PROCESS DESCRIBTION • TFE is introduced into a water- filled reactor along with the initiating chemical. • chamber is only agitated gently. • The PTFE forms into tiny beads. Some of the water is removed, by filtering or by adding chemicals which cause the PTFE beads to settle. industrially
- 14. Processing
- 15. Unlike thermoplastics the viscosity of the gel above the melting point is too high for PTFE to be processed by traditional methods such as injection or transfer and rotational moulding. 1.Compression of the powder at ambient temperature 2. Sintering تلبيد 3. Slow Cooling steps: Processing Cold Compression Moulding Products : PTFE short length Rods, & Plates Advantage: PTFE Products manufactured by this process have good physical properties Disadvantage: PTFE Products of long, continuous length more than 500mm & complex design are difficult to produce due to limited PTFE Resin flow properties
- 16. PTFE Tube Extrusion Machine Advantage PTFE products manufactured by this process are available in long continuously length up to more than 3 meters. Disadvantage The physical properties such as Density, Tensile Strength, Compression Strength are at minimum level due to low compression Product The PTFE products of basic shapes such as Rods up to 150mm Diameter Tubes are manufactured up to 3 Meters . PTFE is continuously fed into one end of straight die tube
- 17. PROPERTIES
- 18. The exceptional physical and chemical properties of PTFE. Polytetrafluoroethylene is a tetrafluoroethylene polymer with a particular molecular structure that gives it the unique physical and chemical properties that distinguish it from other plastic materials, making it suitable for endless industrial applications PTFE PROPERTIES
- 19. Comparison 01 • Excellent dielectric strength at various temperatures and frequencies • High surface resistivity • High volume resistivity • High dissipation factor electrical properties • Chemical inertia: PTFE is inert to almost all known chemicals (except for elemental alkaline metals and fluorine) • PTFE is insoluble at temperatures up to 300°C • Biologically safe and suitable for use in contact with food (FDA certification); maximum safety for use in various applications (the chemical and medical industry and medical applications) • Excellent resistance to UV radiation • Non-flammable • Completely water repellent chemical & physical properties
- 20. • Non-stick and anti- adhesive • Low friction coefficient, even under heavy loads • Wide range of operating temperatures • Excellent workability • Low heat conductivity • Good thermal insulation thermal properties mechanical properties Comparison 02
- 21. Tests on PTFE
- 22. Young's modulus 575 MPa Shear modulus 230 MPa Tensile strength 30.5 MPa Elongation 450 % Compressive strength 23.5 MPa Bending strength 5.5 MPa Hardness 54 Rockwell Impact strength 1.6 J/cm Yield strength 0 MPa Thermal expansion 80 E-6/K Thermal conductivity 0.24 W/m*K Specific heat 1000 J/kg*K Melting temperature 327 °C Glass temperature 127 °C Minimum service temperature -200 °C Maximum service temperature 260 °C Density 2175 kg/m3 Resistivity 1E+22 Ohm*mm2/m Breakdown potential 65 kV/mm Dielectric loss factor 0.00035 Friction coefficient 0.075 Refraction index 1.35 Shrinkage 4.75 % Water absorption 0 % (PTFE) film was pulled apart using tensile substage and the tearing process Testing of Hard PTFE sample on TensileBOT
- 23. applications
- 24. applications in oil and gas industry Enhancing Equipment Performance and Lowering Operation Costs Teflon is the go-to solution for many production and manufacturing issues due to their low coefficient of friction, chemical inertness, dielectric stability, and extreme temperature tolerance. 1 handle: • Release • Heavy wear and abrasion • Extreme temperatures • High loads • Corrosion Cabling for Oil and Gas 2 Deep well exploration and drilling operations resistance in temperatures up to 288 °C (550 °F)—making them ideal for insulation and jacketing, corrosion resistance, and more. Learn more. Heat Exchangers 3 coating or lining for pipes and tubes can maximize well productivity and minimize costs
- 25. Resources https://www.prodeflon.it/en/processing/ptfe-properties https://omnexus.specialchem.com/selection-guide/polytetrafluoroethylene-ptfe-fluoropolymer https://www.matweb.com/search/datasheet_print.aspx?matguid=4d14eac958e5401a8fd152e1261b6843 https://www.teflon.com/en/industries-and-solutions/industries/energy-oil-gas http://www.standard-ptfe.com/production-process-of-ptfe.php