rikkitikkitavi - 28-9-2002 at 05:43
I was cleaning out some old chemicals at my parents house. To my great surprise and joy I found a 5 l plastic container with 2,5 l of 53 % HNO3!
It is most likely made out of PP and has withstand the HNO3 for more than a decade!
I m believe I purchased it in ´91-92!
(at a time when it still was possible to purchase strong acid OTC in Sweden)
It has been in a unisolated, unheated storage subjectet to the full climate changes in south of Sweden (-25 C to + 30 C , at the extremes) However it
has of course been stored in darkness.
The plastic container had obtained a yellow colour but I couldnt see any tendency to other damage.
The nitric acid was clear as water. No signs of NOx dissolved´or decomposition.
I will later test the strength by titration, density measured at about 1,35-1,40 gr/l.
Since the plastic container has the manufacurer stamped on it I will try to verify what kind of plastic material it is made of.
/rickard
vulture - 28-9-2002 at 05:49
I have a bottle of 70% HNO3 from fisher scientific which is made of brown HDPE. Odd, because normally PE ain't resistant to nitric acid. It's a UN
certified bottle...
Microtek - 28-9-2002 at 05:57
Many types of plastic will endure HNO3 at, say, 60 % concentration and normal temperatures. Most of them will break down if employed for distillation,
either from HNO3 attack or due to the NOx that is evolved when distilling at atmospheric pressure.