plastic and strong base

[Doodazzle]

I feel this deserves a seperate thread from the phthalates one.

I read in the book Emergency by Neil Strauss that one should not store plastic water jugs on aconcrete surface as this will cause toxins to leach from the plastic. So, I've been wondering for some time--one of the principle components in cement is lime. Pour some muriatic acid on concrete and it will sizzle just like the baking soda and vinegar from your 7th grade science project volcano.

Internet searches into the matter yield up vague and conflicting information so...


Anyone have any knowledge on the matter? If it merely is the alkalinity of the concrete causing a reaction with the platic then we have more than just solvents to worry about, we also need to worry about our lye and lime.

 

[benzyme]

plastics are nonpolar polymers, lye dissociates in polar solvents; they don't tend to degrade
common plastics like PP, LDPE, HDPE, PET, etc. They do tend to oxidize metals though

 

[SHroomtroll]

i sometime use coke bottles and similar but they always crack in the lid after a few extractions, guess something makes them degrade a bit.

 

[elphologist1]

Back when I was more active with (mostly inorganic) chemistry, I used to keep various common reagents in 1 liter plastic drink bottles. I recall with sodium hydroxide and water solution (if I recall it was 1M or 40g per liter), one day I saw it had leaked out of the plastic bottle because the sodium hydroxide gradually ate away at the plastic. It took several months for this to happen, but it does show that the sodium hydroxide did slowly dissolve the plastic.

 

[benzyme]

I worked in an inorg environmental testing lab, where they stored 12N NaOH in HDPE carboys (they didn't degrade).

for all practical purposes, it's generally a good idea to just prep lye solution as needed.