Cyanoacrylates plasma treatment

Epoxies, isocyanate cured polyester, and cyanoacrylates are used to bond acetal copolymer. Generally, the surface is treated with a sulfuric-chromic acid treatment. Epoxies have shown 150 to 500 psi shear strength on sanded surfaces and 500 to 1000 psi on chemically treated surfaces. Plasma treatment has also been shown to be effective on acetal substrates. Acetal homopolymer surfaces should be chemically treated prior to bonding. This is accomplished with a sulfuric-chromic acid treatment followed by a solvent wipe. Epoxies, nitrile, and nitrile-phenolics can be used as adhesives. 

Ammonia plasma treatment of PE gives strong bonds with cyanoacrylate adhesives coupled with excellent strength retention upon water immersion [41]. It is argued that covalent bonding between the surface amine groups and the cyanoacrylate is more resistant to water than physical bonding alone. 

Plasma treatment of a plastic surface can remove all the surface moisture and parts may need to be left to re-acclimatise prior to bonding with cyanoacrylates. 

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