Degradation of PFA

[kevlar49]

Does anyone have information on resistance of perfluoroalkoxy (PFA) composites with carbon fibers to galvanic corrosion and hydrolysis? We're looking to see if it will have issues when exposed to DI water up to 302F.

 

[Compositepro]

PFA resin is virtually immune to hydrolysis. However, electrical contact between carbon and metal will still cause galvanic corrosion of the metal.

 

[kevlar49]

Thanks compositerpro.

Is there a standard test or a reference I can review to determine hydrolysis resistance? Is there any concern for galvanic corrosion between the resin and the fibers as well as a metal couple?

 

[Compositepro]

Galvanic corrosion can only occur between electrically conductive materials (metals and carbon). What is referred to as galvanic corrosion of of some resins is actually the hydrolytic degradation of resin caused by the the caustic byproducts of the galvanic corrosion of aluminum in contact with carbon.

For resin chemical resistance, refer to the resin manufacturer's data sheets. PFA is a melt processable fluoropolymer in the Teflon family, which include PTFE and FEP.

 

[btrueblood]

From experience, PFA is resistant to hydrolysis in saturated water/steam service to at least 250 to 275 deg. F. Likely, it is like Teflon in that it won't suffer hydrolytic attack up to the point where it melts or degrades by oxidation/decomposition, around/above 200 - 260 C (400-500 F).