1
$\begingroup$

In my current job we use gloveboxes, but unlike most we use disposable PVC bags on the entry ports instead of fixed gloves. The bags have an O ring which is stretched onto a spigot proud of the porthole and are then clamped into place. They get disposed of and replaced after every use.

Like this but our glovebox is permanent ^ Like this but our glovebox is permanent ^

The problem with the PVC bags is that they are releasing hydrogen chloride. I'm in a team investigating a replacement material; however none of us are chemists or material scientists!

The material needs to be able to fit over 6” and/or 10" spigots, allow hydrogen to pass, and contain no halides.

So far we have considered using HDPE + plasticizer, and are trying to find a way to make it, although we are not sure it will work until we try it. We have also looked into using polyester, but we couldn’t find a clear and stretchy version.

$\endgroup$

closed as too broad by M.A.R., Todd Minehardt, airhuff, ron, DrMoishe Pippik Apr 4 '18 at 21:57

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ What good is speculating about a useful material if you can't find a supplier for useable gloves or bags? Try out what you can get your hands on! And sorry, stupid question: What or whom is this supposed to save from what kind of danger? $\endgroup$ – Karl Apr 3 '18 at 19:54
  • $\begingroup$ Hi @Karl We are doing that as well, but the materials local suppliers can give us might not be the best, or right for the job. Unfortunately I can't tell you what the hazard is, but I can tell you it's big enough that if the best material isn't available in bag form, we'll have it made. $\endgroup$ – Snr Srub Apr 3 '18 at 20:01
  • $\begingroup$ If your PVC gloves are releasing HCl then your problem is not PVC. PVC does not, under normal circumstances, release HCl (unless you expose it to excessive heat of very nasty chemicals). $\endgroup$ – matt_black Apr 4 '18 at 10:20
  • $\begingroup$ Yes the PVC would not normally produce HCl but it does due to the way we're using it, it's a pretty weird situation. We can't change their process so we have to change the material. $\endgroup$ – Snr Srub Apr 4 '18 at 14:06
  • $\begingroup$ An issue is that you expect it to block HCl but to pass H2. It would make more sense to change the process to eliminate the HCl fumes, e.g. absorb it. $\endgroup$ – DrMoishe Pippik Apr 4 '18 at 21:59
1
$\begingroup$

I think what you should try is thermoplastics elastomers. For general descriptive overview, read: https://en.wikipedia.org/wiki/Thermoplastic_elastomer

DUPONT has a long line of Chemical Resistant Elastomers, but may be expensive for your use, yet I mention it here because you said your team may consider custem made units to fix it in your glove boxes, so it could be quite expensive. Following is a cheaper option, but you can find more by just googling under "thermoplastics elastomers": Kent Elastomer Products, Inc., PO Box 668, Kent, OH 44240 (1-800-331.-4762); email: info@kentelastomer.com (https://www.kentelastomer.com/cost-of-cheap/)

$\endgroup$
  • $\begingroup$ Thanks, I have emailed DuPont and currently waiting for an response. $\endgroup$ – Snr Srub Apr 4 '18 at 14:05
0
$\begingroup$

I think what you want is a fluoropolymer, like Teflon PTFE or Viton. These are used to coat magnetic stir bars, they're that unreactive. That is, as long as you don't raise their temperature over 300c - otherwise they'll decompose into HF (not so good).

This company seems to sell COTS fluoropolymer bags (no affiliation, just found them on Google):

http://www.welchfluorocarbon.com/custom-manufacturing/standard-products/teflon-bags/

You can also buy plain Teflon sheets in a variety of thicknesses from standard suppliers like McMaster-Carr (8569K74).

Viton fluorocarbon is a little stretchier, and might be easier to work through - it's also very chemical resistant. Again, sheets are easy to buy.

If you absolutely need a "glove" shape, you can try vacuum-forming or blow-molding - in both cases, just heat an area of the material you want to re-shape (with, say, a heat gun), then either push a glove shaped mandrel through or try injecting a stream of air. This likely won't work with many fluorocarbons, though.

$\endgroup$
  • $\begingroup$ Doesn't Teflon contain Fluorine? Wouldn't that mean it includes halides? $\endgroup$ – Snr Srub Apr 4 '18 at 14:05
  • $\begingroup$ @SnrSrub Whoops, sorry, I totally missed that requirement. $\endgroup$ – 0xDBFB7 Apr 4 '18 at 17:59

Not the answer you're looking for? Browse other questions tagged or ask your own question.