Chemistry Forum

I can make some glue now, here is the recipe.

INGREDIENTS
copper sulphate
glycerine
methanol
citric acid
oxalic acid

METHOD

Solute the copper sulphate in glycerine, use a bit of heat and wait till fully dissolved.
Then add 3:1 citric acid to the liquid, and then put on low heat until it gets double thickened.
Then you add methanol, and u keep topping it up with methanol on the heat because ur
continuing the rest of the esterification soluted in methanol. the methanol is evaporating as
it is happening, so for the next 45 minutes or so, you have to keep replacing the methanol as
it evaporates. It may take 2/3 of a litre. You want to complete the esterification inside of
the methanol, so I think it stops bubbling when its done.

But once its gone for long enough, you take it off, and u add enough oxalic acid to make it 1:1
with the copper sulphate and that makes it water resistant, (cause copper oxalate is highly water insoluable)
You could think that the copper oxalate would precipitate out now, (It would if it were in water)
but it actually doesn't, it stays locked inside the polymer.
And there is your air drying glue inside of a methanol solvent. Its like varnish, when the methanol evaporates
it leaves behind a connected solid.

I was wondering if I replace the glycerine with ethyl citrate, will I get a stronger glue from it?

It is occurring, hence you have to continuously refilling the methanol as it evaporates for the next 45 minutes or so. Two thirds of a liter might be needed. I believe it stops bubbling whenever you desire to finish the esterification inside the methanol.

fencerrooster wrote: ↑Wed Aug 14, 2024 6:08 pm It is occurring, hence you have to continuously refilling the methanol as it evaporates for the next 45 minutes or so. Two thirds of a liter might be needed. I believe it stops bubbling whenever you desire to finish the esterification inside the methanol. doodle baseball

thanks for your instructions. I followed it and it successfully esterified inside the methanol.

hiiiii,
Replacing glycerine with ethyl citrate in your glue recipe may lead to different adhesive properties. While glycerine acts as a plasticizer, enhancing flexibility, ethyl citrate could alter viscosity and bonding strength. Its compatibility with copper sulfate, citric acid, and methanol is crucial, so testing is essential to determine if it produces a stronger glue. Conduct experiments to compare the adhesion strength and drying properties of both formulations for the best results.

Regard,