Bedlasky - 1-7-2021 at 20:33
Hi.
I opened yesterday jar with MEK and saw some white crust on the lid. Lid was was covered before with some thin plastic film inside, so I think that
the crust is just plastic destroyed by ketone. But I am not sure and think that this also may be peroxide. Is it possible or it is nonsense?
macckone - 1-7-2021 at 20:37
It is possible and if it is then it is dangerous.
Bedlasky - 1-7-2021 at 21:04
Thanks. I opened the jar, put in to the lid some acetone, ammonium ferrous sulfate and little bit of HCl. In to MEK I added some ammonium ferrous
sulfate and little bit of HCl. Ammonium ferrous sulfate make nice green solution, no signs of rusty Fe(III). And that solid in the lid looks like
wierd goo. When I carefully mixed ferrous salt in the lid and I very easily scraped off some plastic during mixing and see metal underneath it. So it
seems that white solid is just plastic.
macckone - 1-7-2021 at 21:08
plastic is much better than organic peroxide.
Bedlasky - 1-7-2021 at 21:13
Yeah it is 
.