Good Alternative for Plasticized PVC [closed]

Question

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 ^

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.

Answer 1

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: [email protected] (https://www.kentelastomer.com/cost-of-cheap/)

Answer 2

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.