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Super Glue mini-bottle that doesn't harden by itself while stored capped?

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Alex Eisenhut:
what about the stuff with separate activator? Maybe the glue part keeps longer in that case?

mzzj:
Hobbyking no-name cyanoacrylate has exceeded all of my expectations with self-life: I had to check from old emails and I have ordered the bottles in 2008/2009!
On top of that it was dirt cheap, 5 usd for large 50g 1.7oz bottle.
I have kept the bottles in fridge but sometimes they have been sitting also half a year in room temperature.

Nowadays it seem to be even cheaper but no guarantees if it  is same stuff as nearly 15! years ago.
https://hobbyking.com/en_us/hobbyking-super-glue-ca-50g-1-7oz-medium.html

jpanhalt:

--- Quote from: edavid on April 23, 2023, 02:24:45 pm ---And I hope everyone understands that it lasts longer in the refrigerator because of the low humidity, not the temperature.  Room temperature + silica gel is just as good.

--- End quote ---

I didn't realize it was only humidity.  The relative humidity in my refrigerator is quite a bit higher than room air.  Absolute humidity is approximately the the same as as room air most of the time.   That is there is no condensation inside the refrigerator except on very humid Summer days.*  Do you have a reference to support your view?

On the other hand, the standard polymerization reaction is base catalyzed as mentioned before (attachment 1).  One might expect that reaction to be affected by temperature.  In addition, the ionization of water is strongly affected by temperature:


--- Code: ---T (°C) Kw (mol2 dm-6) pH pOH
0 0.114 x 10-14 7.47 7.47
10 0.293 x 10-14 7.27 7.27
20 0.681 x 10-14 7.08 7.08
25 1.008 x 10-14 7.00 7.00
30 1.471 x 10-14 6.92

Source: https://chem.libretexts.org

--- End code ---
Thus, at 25°C the concentration of OH- (a base) is almost 10X3X the concentration at 0°C.  Since CA is in great excess, one would expect that 10-fold decrease in the other reactant to have a significant effect.

*EDIT: Assuming you mean open in the refrigerator.  I keep my CA sealed in canning jars whether in the refrigerator or freezer.  The absolute humidity is the same as when put in the jar, except for any decrease related to initiating the polymerization.

EDIT2: Ionization constant is the product of [H+] and [OH-]. Thus it is approximately only 3X not 10X.  Fixed in text.  Sloppy on a Sunday afternoon.  It now agrees with the pOH.

rdl:
From what I've read, before being opened refrigerated storage can extend the usable life of CA glue by up to 50%. After being opened, air enters the container. Any moisture it brings will condense when cooled and lead to problems, so storing opened containers at room temperature is recommended.

antenna:
Heat a hot glue stick with a lighter and apply the hot glue to the tip of the tube.  Thats what I use and those cheap single use tubes they intend to be tossed out actually last until they are empty that way! I get months of use from those, and I am sure the bigger bottles would last a long time like that too.  The glue comes of easy with a twist.

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