Re: Chemical resistance of PTFE against hydrochloric acid |

Posted by Diffusion Polymers on

In Reply to: Chemical
resistance of PTFE against hydrochloric acid posted by Eric Li on

Dear Eric Li,

An increase of temperature,
increases the diffusion coefficient [D: m2/s] and the chemical corrosion rate
[k: m/s]. This effect can be described with the Arrhenius law.

The pressure does not have
an influence on the two described rate constants, nor does it have an influence
on the Solubility for diffusion or on the Hydrochloric acid concentration as
liquids are hardly compressible.

However a pressure increase
with a factor 2 forces 2 times as much liquid through the PTFE liner (Maxwell
Stefan equation). This will lead to a chemical degradation rate increase with a
factor 2 when there is a first order corrosion rate dependence on the
Hydrochloric acid concentration.

If you could state the
exact Hydrochloric concentration that you are
interested in, including the process conditions, then we are able to do the
calculations. Perhaps Hydrofluoric acid is also of interest.

Best Regards,