It is specially designed… Obviously HP Fibers = Good Resistant to chemical attack, but…. Strong chemical bonding systems within polymeric structure. Basicallyaliphatic hydrogen atoms increase the chemical resistance.
• It is a chloro fiber.• Minimum 50 % Vinylidene chloride units.• 85 % of Vinelidine chloride units as Vinyon.• 80 % of Vinelidine chloride units as Saran.• Polymer Molecular weight is higher than PVC.
• The melting point of pure homo- polymer is close to decomposition point.• So dry / wet spinning is suitable for homo polymer production.• Less than 15 % co-monomers such as vinyl chloride, acrylonitryle, metha acrylate were added.
PVC PVDC Optical Transparent Transparent Tmelt 75 – 105 ºC 172 ºCH20 Absorption 0.04-0.4% (24h) 0.1% (24h) Oxidation Good Good ResistanceUV Resistance Poor Good Solvent Poor Good Resistance Alkaline Excellent Excellent ResistanceAcid Resistance Good Excellent 7
Strong backbone structureSo it causes high degree of chemical resistance and high degree of order.
Allforms of PVDC are polymerized using the base monomer of vinylidene chloride.The co-monomer gives the polymer more characteristics that help with specific applications.
Accidentally discovered on April 6, 1938 by Roy. Fluoropolymeric fibers & be a very expensive Leading utilization Polymer ( Resins, Plastics, Fibers Films, Coatings, Moldable Forms, Powders)
By 1941, PTFE had been patented and had its first brand name Teflon®.By 1946, the resin product was being used to produce machine parts for military and industrial applications.In the 1960s it began its life in the arena of nonstick cookware.
Sold under various brand names, including Gore-Tex® and Zylon®. Itis used in a wide range of industries from aerospace to pharmaceuticals…
PTFEhave poor in Fusible & less soluble properties. The fibers is produced in Dispersion Spinning. PTFEis blend with Sodium alginate (supporting polymers) and make a viscous solution, Then it is extruded like melt spinning
After extruded the filament kept in oven (380ºC). Dueto high temp, the supporting polymers will be easily remove from the PTFE filament. From this way PTFE is produced.
PVDF, PVF and FEP fibers have lower melting point. They also have lower LOI values and hence increased flammability. However, PVF and PVDF, excellent tensile properties, are used where a combination of good tensile properties and chemical resistance is required.
Chemical Properties Chemical resistance to corrosive reagents Non solubility Durability Non-adhesiveness Non-flammability Electrical Properties Low dielectric constant High surface resistivity Mechanical Properties Flexibility at low temperatures Stability at high temperatures
PTFE is one of the polymer is suitable for high and low temperature applications and (–260 ºC to 260 ºC).(LOI) for PTFE is greater than 94
PTFE has outstanding electrical properties ( even high temperatures)
Thechemical resistance of PTFE is outstanding even in comparison to other Fluoropolymer. Atroom temperature PTFE is only attacked by molten alkali metals and fluorine. PTFE is resistant to UV radiation, but it will degrade in Gamma Radiation
• Gaskets, Packing, Bearings and Bushings• Chemical processing equipment: piping and tubing, seals, heat exchangers and porous filter media.• Aerospace: fuel, lubricant-resistant tubes and seals.• Medical and analytical equipment: Tubing, Seals & Gaskets
Electrical equipment: electrical terminal insulation, wire and cable insulation, and high temperature moldings. Non-stickcoatings: cookware and other domestic products; industrial equipment such as rolls, conveyor belts, and welding equipment; and compression and slide bearings
The monomer TFE is a confirmed animal carcinogen with unknown relevance to humans.
High cost High temperature resistance High strength Good electrical properties and toughness Outstanding chemical resistance
It is semi crystalline aromatic thermoplastic polymer.Itcan produced through melt spinningChemically PEEK containing 2 ether and 1 ketone groups.So the polymer is fully linear and aromatic structure.Technically difficulty and high cost of purifying poly ether ketones for producing monomer
Advantages Very high continuous use temperature (300 °C) Outstanding chemical resistance Outstanding wear resistance Excellent hydrolysis resistance Excellent mechanical properties Very low flammability and smoke generation Resistant to high levels of gamma radiation 58
Advantages and Disadvantages ofPolyketones Disadvantages High material cost High processing temperatures
Aerospace: replacement of Al Fuel line brakes to replacement of primary structureElectrical wire coating for nuclear applications, oil wells, flammability-critical mass transit.
Other applications Chemical and hydrolysis resistant valves (replaced glass) Internal combustion engines (replaced thermosets) Cooker components (replaced enamel) Automotive components (replaced metal) High temperature and chemical resistant filters from fiber Low friction bearings