materials chemical compatibilty study

When making acetyl chloride I used gaseous HCl. During that experiment I learned that natural rubber tubing and nylon tubing connectors degraded. During "foamovers" of the con H2SO4 moisture absorber further degradation was apparent, especially for the nylon connectors.

Using Cole-Parmer's chemical compatibility chart:

http://www.coleparmer.com/Chemical-Resistance

I found what appeared to be compatible materials not only for HCl generation but also for Cl2 generation. I assumed both would be dried using con H2SO4 and therefore likely to be also subjected to this acid during foamovers.

Here is what I came up with:

1. PVDF tubing connectors (not too expensive, reuseable)
2. Tygon tubing (cheap, expendable)
3. 1/4" ID Viton (soft) tubing (not too expensive, reuseable)

I used these materials yesterday during an experiment with gaseous Cl2. The results were entirely acceptable. The PVDF and Viton showed no degradation when exposed to Cl2 and con H2SO4. The Tygon tubing turned from clear to frost white internally but easily retained its functionality.

Shown below are pictures of the connectors, Tygon tubing, and some standard rubber stoppers of unknown composition. You can see that the end of the small holed stopper has become severely swollen. But it is a veteran of several exposures to HCl gas and Cl2. It must now be taken out of service.



[Edited on 18-9-2014 by Magpie]