Beschreibung
Cyanoacrylate adhesives cure within seconds due to water in a normal atmosphere, which can lead to problems in processing and in large-area bonding. The aim of this work is therefore to overcome the problem by using a water-free process atmosphere. In the scope of this work, a standard argon protective atmosphere and a novel argon/silane atmosphere are compared with an air atmosphere. To validate the influence of the atmosphere the adhesive strength is investigated by tensile tests as well as the curing process via Raman spectroscopy. In order to explain differences in curing and strength the fracture surfaces of selected samples are examined by confocal microscopy. While the argon atmosphere shows slower curing and thus longer processing capability, only low tensile strengths after 72 h are achieved. The novel oxygen-free argon/silane atmosphere shows a similar delayed cure, but the tensile strengths achieved after 72 h are comparable to those in air. The addition of silane thus allows a more flexible processing without disadvantages in the final mechanical strength.
