Key Difference –ptfevs. PFA
ptfeand PFA are abbreviations for two synthetic聚合物, Polytetrafluoroethylene and Perfluoroalkoxy respectively. They are fluoropolymers and share most properties in common. The most commonly known and widely used fluoropolymer is PTFE; also known asTeflonand the brand name of PFA isTeflon PFA。Thekey differencebetween PTFE and PFAcomes from the resins that are used to make the polymer。PFA融化了可加工的,并且比铁氟龙更通用。但是,PTFE具有良好的特性,例如吸水量较低,不反对风化。
聚四氟乙烯是什么?
The commercial name of PTFE (Polytetrafluoroethylene) isTeflon; a fluoropolymer with advanced properties such as高化学耐药性, low andhigh-temperature能力,抵抗力weathering,low摩擦,electrical andthermal insulation和“滑水。但是,与其他人相比,PTFE的机械性能相对较低plastics; but remains stable over a wide temperature range. Different techniques are used to fabricate PTFE resins to form parts; ram extrusion, screw extrusion, compression molding, and paste extrusion with an extrusion aid. Three basic steps are common in these all techniques: cold forming, sintering, and cooling.
What is PFA?
PFA (Perfluoroalkoxy) is a fully fluorinated, translucent polymer and is commercially popular asTeflon PFA。It is边缘柔性聚合物材料with alow friction系数和exceptional non-stickproperties. Moreover, it is a strong and hard material that shows highresistance to stress crackingand没有反应几乎所有化学物质和溶剂。此外,PFA还有一个good temperature tolerant capacityand can be used in both high and low-temperature conditions. Itsdielectric常数是极好的,化学稳定性也很高。
In producing PFA, it is melted and processed at very high temperatures; therefore it is extremely difficult to mold the PFAresin。Due to this fact, it is highly crystalline, viscous and extremelyshearsensitive.
What is the difference between PTFE and PFA?
Structure:
ptfe:PTFE具有-c的重复单元2F4-, it contains only carbon and fluorine atoms.
PFA:The repeating unit of PFA polymer is given in the below. All the carbon atoms are fully fluorinated, and two carbon atoms are bonded together via an oxygen atom (-C-O-C).
Properties:
ptfe:ptfeis ahydrophobicsynthetic polymer with a low friction coefficient. It has excellent thermal and electrical insulation properties. It has high-density value and cannot be melt processed. To form required shapes, it needs to compress and sinter. Its mechanical properties are comparative to with other plastics; however mechanical properties can be enhanced by adding fillers.
PFA:PFA is known as a flexible polymer with excellent chemical resistant and temperature tolerant properties. However, it is less heat resistant than PTFA. It has gooddielectricproperties, and the dielectric constant is equal to 2.1.
应用程序:
ptfe:Teflon is popular as a non-stick coating in cooking pans and other modern items of cookware. It is also used in containers and pipes when handling corrosive and highly reactive chemicals due to its non-reactive properties. The other common application of PTFE is the use of as a lubricant to reduce friction in machinery.
PFA:PFA is commonly used to produce plastic laboratory equipment since it is optically transparent, flexible and chemically resistant to nearly all chemicals and solvents.It is also commonly used for tubing in handling critical or highly corrosive processes. In addition, PFA is used as sheet linings for chemical equipment, because it can use as an alternative for more expensive alloys and metals as a carbon steel fiber reinforced plastics (FRPs).
Image Courtesy:
1.Teflon itemsBy Cjp24 (Own work) [Public domain], via Wikimedia Commons
2. “Pfa tubing“。[CC BY-SA 3.0]通过Wikipedia
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