DAIKIN FEP Neoflon NP-40 FEP Granules Powder Engineering Plastic

English name: FEP (Fluorinated ethylene clone) FEP is made by copolymerization of tetrafluoroethylene and hexafluoropropene. The
content of hexafluoropropene is about 15%. It is a modified material of polytetrafluoroethylene. Full name: fluorinated
ethylene-propylene copolymer (perfluoroethylene-propylene copolymer), referred to as poly (perfluoroethylene-propylene), also
abbreviated as F46. FEP has a melting point of 580 ° F and a density of 2.15g/CC (g/cm3). It is a soft plastic with lower tensile
strength, wear resistance and creep resistance than many engineering plastics. It is chemically inert and has a low dielectric
constant of about 2.1 in a wide temperature and frequency range. This material does not ignite and can prevent the spread of
flame. It has excellent weather resistance, low friction coefficient, and can be used from low temperature to 392 ° F. The
material can be made into granular products for extrusion and molding, powder for fluidized bed and electrostatic coating, and
water dispersion. Semi-finished products have films and plates. Bar and single fiber. The FEP distributed in the U.S. market
includes DuIPont's Teflon brand, Daikin's Neoflo brand, and Hoechst Cellanese's IHoustaflow brand. Its main purpose is to make the
inner village of pipes and chemical equipment, the surface layer of drums, and various wires and cables, such as aircraft hook
line, booster cable, alarm cable, flat cable and oil well logging cable. FEP film has been seen as a thin coating for solar
collectors. F46 resin not only has the characteristics similar to polytetrafluoroethylene, but also has the good processing
properties of thermoplastic. Therefore, it makes up for the difficulty in processing PTFE and makes it a substitute for PTFE. It
is widely used in the production of wires and cables in the transmission lines of electronic equipment used at high temperature
and high frequency, the connecting lines inside electronic computers, aerospace wires and their special purpose installation
lines, oil pump cables and the insulation layer of the winding lines of submersible motors. According to the processing needs, F46
can be divided into three types: granular, dispersion and paint. Granular materials can be used for molding, extrusion and
injection molding according to their melt index; The dispersion solution is used for impregnation and sintering; The paint is used
for spraying, etc. 1. Structural characteristics of PFEP Like polytetrafluoroethylene, F46 resin is also a completely fluorinated
structure. The difference is that part of the fluorine atoms in the main chain of F46 are replaced by trifluoromethyl (- CF3), as
shown in the following figure: picture PTFE structure picture FEP structure It can be seen that although F46 resin and
polytetrafluoroethylene are composed of carbon and fluorine elements, and the carbon chain is completely surrounded by fluorine
atoms, there are branches and side chains on the main chain of F46 macromolecules. This difference in structure has no significant
impact on the upper limit of temperature range of materials under long-term stress. The upper limit temperature of F46 is 200 ℃,
while the maximum service temperature of PTFE is 260 ℃. However, this structural difference makes F46 resin have a fairly definite
melting point and can be processed by general thermoplastic processing methods, which greatly simplifies the processing process.
This is what polytetrafluoroethylene does not have. This is the main purpose of modifying polytetrafluoroethylene with
hexafluoropropylene. 2. Performance of PFEP The content of hexafluoropropylene in F46 has a certain effect on the properties of
the copolymer. At present, the content of hexafluoropropylene in F46 resin is usually about 14%~15% (mass fraction). 2.1. Physical
properties At present, there is no feasible method to determine the molecular weight of F46 resin. However, its melting viscosity
at 380 ℃ is lower than that of polytetrafluoroethylene, which is 103~104Pa. s. It can be seen that the molecular weight of F46 is
much lower than that of PTFE. The melting point of F46 varies with the composition of the copolymer. When the content of
hexafluoropropylene in the copolymer increases, the melting point decreases. According to the results measured by differential
thermal analysis, the melting point of domestic F46 resin is mostly between 250~270 ℃, which is lower than that of
polytetrafluoroethylene. F46 resin is a crystalline polymer with lower crystallinity than polytetrafluoroethylene. When F46 melt
slowly cools to the temperature below the crystal melting point, macromolecules will recrystallize with crystallinity between 50%
and 60%; When the melt is rapidly cooled by quenching, the crystallinity is small, between 40% and 50%. The crystal structure and
morphology of F46 are spherulite, which varies with the resin, processing and molding temperature and heat treatment methods. 2.2.
Electrical insulation performance The electrical insulation performance of F46 is very similar to that of PTFE. Its dielectric
coefficient is almost constant in the wide range from deep cold to the maximum operating temperature, from 50Hz to 1010Hz UHF, and
very low, only about 2.1. The dielectric loss tangent changes with frequency, but it does not change with temperature. The volume
resistivity of F46 resin is very high, generally greater than 1015 Ω. m, and changes slightly with temperature, and is not
affected by water and moisture. Arc resistance is greater than 165s. The breakdown field of F46 increases with the decrease of
thickness. When the thickness is greater than 1mm, the breakdown field strength is above 30KV/mm, but does not change with the
change of temperature. 2.3. Thermal performance The heat resistance of F46 resin is only inferior to that of
polytetrafluoroethylene, and it can be used continuously in the temperature range of - 85~+200 ℃. Even under the limit of - 200 ℃
and+260 ℃, its performance will not deteriorate and can be used for a short time. The thermal decomposition temperature of F46
resin is higher than the melting point temperature, and significant thermal decomposition occurs only when the temperature is
above 400 ℃. The decomposition products are mainly tetrafluoroethylene and hexafluoropropylene. Due to the fact that F46
macromolecules usually have the same terminal groups that will decompose at temperatures above the melting point, proper
ventilation must also be paid attention to when processing at temperatures above 300 ℃. F46 is quite stable below the melting
point temperature, but the mechanical strength loss is large at 200 ℃. The increase of melt index can be used to analyze the
decrease of melt viscosity and the thermal decomposition of copolymer. F46 is still not completely hard and brittle at - 250 ℃,
and still has a small elongation and certain flexibility, which is even better than polytetrafluoroethylene, and is inferior to
all other types of plastics. 2.4. Chemical resistance The chemical resistance of F46 is similar to that of
polytetrafluoroethylene, and has excellent chemical resistance. Except for the reaction with fluorine element, molten alkali metal
and chlorine trifluoride at high temperature, it will not be corroded when contacting with other chemicals. 2.5. Mechanical
properties Compared with PTFE, F46 has a slightly higher hardness and tensile strength, and a slightly higher friction
coefficient. F46 has good creep resistance at room temperature; However, when the temperature is higher than 100 ℃, the creep
resistance is less than that of PTFE. 2.6. Other performance F46 resin has excellent oxidation resistance in the atmosphere and
high atmospheric stability. The irradiation resistance of F46 is better than that of polytetrafluoroethylene and slightly inferior
to that of polyethylene. In air and at room temperature, the minimum absorbed dose for F46 to begin to change its performance is
105-106rad (103-104Gy), so it can be used as an irradiation resistant material.