What Are Fluoropolymers?
A fluoropolymer is a fluorocarbon-based polymer that features multiple strong Carbon-Fluorine bonds, and are characterized by their high resistance not just to solvents, but to acids and bases as well. They are quite stable, due to the strong stability of the multiple carbon-fluorine bonds, which is considered to be one of the strongest of bonds in organic chemistry. When characterized mechanically, they can be referred to as thermosets, or thermoplastics. They are capable of being either homopolymers, or copolymers.
PTFE - Also known as Polytetrafluoroethylene, PTFE is a synthetic fluoropolymer of tetrafluoroethylene, it is a hydrophobic solid. A white solid thermoplastic polymer, it combines high strength, toughness and self lubrication. Additionally, it has superior chemically resistant properties to most other substances, making it ideal for use in a multitude of laboratory applications. It has a melting point of approximately 335°C/635°F.
FEP - Also known as Fluorinated ethylene-propylene, FEP is copolymer that is composed of hexafluorophopylene and tetrafluoroethylene. It shares many of the same properties as PTFE, including its resistance to caustic agents. While FEP does have a lower melting point of 260°C/500°F, it is vastly superior to PTFE when exposed to detergents.
PFA - Also known as Perfluoroalkoxy, it is a copolymer that has been composed of tetrafluoroethylene and perfluoroethers. Like FEP, it has many of the same properties to PTFE, but is considered to be more of a premium resin, as it has better resistance to hostile environments than PEF. Its melting point is roughly in between that of PTFE and FEP, coming in at approximately 305°C/582°F.
ETP - One of the newer polymers, ETP has been steadily gaining ground as a replacement for expensive materials such as FFKM or fluoropolymer, while at the same time providing even greater chemical compatibility to the standard FKM grades. It has excellent resistance to acids, hydrocarbons, and low weight molecular weight esters, ketones and aldehydes, with an inherent resistance to attack by bases and volume changes in highly caustic solutions and hot water. ETP is a tetra-polymer, combined of ethylene, tetrafluorethylene (TFE), and perfluoromethylvinylether (PMVE). This gives it a chain structer that is designed to give it excellent resistance to base and polar fluids, while maintaining good flexibility at low temperatures and general fluid resistance that is comparable to other FFKM materials.