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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: alibaba on August 31, 2007, 01:48:17 PM

Title: chemical resistance question
Post by: alibaba on August 31, 2007, 01:48:17 PM

i know this may sound silly, but i was wondering. If a packing material has excellent chemical resistance to a specific chemical (according to chem resistance charts) does that mean that if the chemical is packed in that material there will be absolutely no leak in any form(smell) - perfect packaging, no loss due to molecules breaching the package??

thanks

Title: Re: chemical resistance question
Post by: Bakegaku on September 01, 2007, 12:53:38 PM

I'm not entirely sure what you mean, but I think what it means is that the chemical won't corrode or otherwise react with the packaging.  I suppose if there are no openings in the packaging then none of the chemical would escape, though.

Title: Re: chemical resistance question
Post by: Dan on September 01, 2007, 04:12:02 PM

Quote from: alibaba on August 31, 2007, 01:48:17 PM

does that mean that if the chemical is packed in that material there will be absolutely no leak in any form(smell)

I suppose that this is theoretically possible to do, but it relies on a perfect seal, and no contamination on the outside of the package while you were putting it into the contianer.
I'm not familiar with these chemical resistance charts, but I don't think that chemical resistance would necessarily be an indicator of permeability. That would have more to do with the structure of the material. For example, a cotton T-shirt is chemically resistant to nitrogen gas, but permeable to it because the fibres are far apart in comparison to the size of nitrogen molecules.

If the consequences of this "smell" being detectable are particularly unfavourable, I wouldn't bet on anything. Some compounds smells can be detected at extremely low concentrations, especially if you have some highly specialised equipment, for example: a dog's nose.

Title: Re: chemical resistance question
Post by: alibaba on September 03, 2007, 04:16:04 AM

hi, thanks for your replies,
i just wanted to clarify just one more thing. i have the follwoing setup:

I intend to pour MTBE (methyl-t-Buthyl ether) into a polyamide bag (nylon -cooking grade, heat resisatnt,guaranteed to retain all odours within bag, 100% resistant to MTBE). this will have a 100% airtight heatseal.

will this mean that there will be no leak of any kind?

I really aprreciate your *delete me*  :)
Thank you