Solving Problems with Chemicals


Super Glue : Reaction & Bonding Mechanism

Many of us might use the cyanoacrylate adhesive ( CA )  before, and impressed by its great performance of
rapid setting, high bonding strength and ease of handling, among the popular brands and types : Loctite Prism instant adhesives, 3M Pronto instant adhesives , Krazy glue, Super Glue, Gorilla super glue, elephant glue to name but a few.

These CA adhesives react with moisture on slight-alkaline surfaces, polymerization takes place in a few seconds, meaning bonding begins and holds two mating surfaces together.

The following illustrations  may be explaining the reaction and bonding mechanisms in a simpler way.
CA monomers ( black )  in a container are kept in liquid state, prevented from polymerization by acid stabilizers (  rings ).

CA monomers ( black ) come into contact wiith surface moisture / water molecules ( blue ) and neutralise the acid stabilizers (  rings ).

Polymerization chain reaction is triggered, CA monomers undergo polymerization and a massive complicated polymer structure is formed. This solid state substance bonds two mating surfaces firmly, with high shear strength, typically ranges from 2000 - 3900 psi.

Tips & Tricks of CA adhesives
* CA adhesives perform best under the condition with relative humidity 40 - 60%.
* Apply CA adhesive sparingly on the surface to be bonded.
* Apply to only one surface.
* Curing speed can be acceleratedd and excessive CA adhesive can be post-cured with accelerators . Loctite 712, Loctite 7452, Loctite 7113 may be used  according to specific conditions.
* Low surface energy plastics, eg Polyolefins, can be bonded by applying adhesion promoters. Loctite 770, Loctite 793 may be used according to specific conditions.

For more information on  Loctite instant adhesive, do feel free to contact us : ,