The reinforced elastomer formulations offer superior mechanical properties compared with the nonreinforced formulations, and can handle higher forces before succumbing to substrate failure. Consequently, adhesive bond failure is more likely than substrate failure, making differences in bond strength easier to identify between adhesive types. In Table II, those elastomers are highlighted that achieved a significant improvement in bond strength when the plastic primer was used. Elastomers that showed an improvement in bond strength when a plastic primer was used along with a cyanoacrylate. A surface-insensitive ethyl cyanoacrylate was used in all testing.
All bond strengths are in psi.
Adding antistatic agents to plastic formulations has proven to significantly improve the bond strength of cyanoacrylates to many materials. In order to determine whether this effect could offer a similar benefit for elastomeric materials, antistatic agents were compounded with each of the elastomers studied. Table IV illustrates those elastomers that consistently showed improved bond strength when compounded with antistatic agents. Elastomers that benefited from the addition of an antistatic additive. Black rubber-toughened cyanoacrylate was used in all testing.