UCSB Science Line (2024)

Are you sure that the superglue "reacts"with thesodium bicarbonate. Are you sure that is would notdo the same with chalk (calcium carbonate). Ifsuperglue sets around some powder, it usuallyresults in very strong cement. Do try with chalkpowder, or with sawdust. Please be very carefulwith superglue.

The question seems to be whether the supergluejust sticks the baking soda together really wellor whether there is some additional chemistryinvolved. I haven't read enough to have an opinionabout it. I left a drop of superglue on mydesktop, and it dried into a super-hard spot; Idon't know if the baking soda makes it harder andstronger or not.

The bicarbonate (even water) starts the reactionbetween one cyanoacrylate and another one. Thebicarbonate and cyanoacrylate form an ion whichreacts with another cyanoacrylate molecule. Thisstarts a chain reaction (polymerization) whichends up a very good adhesive.

A monomer, such as methylcyanoacrylate (thesubstance in super glue), with two electron-withdrawing substituents can be polymerized withvery mild nucleophiles such as Br, CN, amines orOH. The monomer polymerizes on contact with manysurfaces. Most often it is initialized by thepresence of water (the OH ions from water). If youhave sodium bicarbonte present, traces of water(from the surface or air) will react and makeNaOH. The reaction is thefollowing:

NaHCO₃ + H₂O-----> NaOH + H₂CO₃NaOH

is avery good starter of the polymerization reaction.It will make the reaction go very fast. Since thisis an exothermic reaction (energy gets released)the H₂CO₃ will break up intoH₂O and CO₂ . The water willevaporate and that should be the fume you havenoticed. You should also see theCO₂. This is my guess on what ishappening.