Zdrojový dokument:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 23/2017
ISSN:1211-5541
Abstrakt:
In this contribution, the results of measurements are presented concerning
rheological and mechanical properties of polyurethane adhesives used in the
automotive industry. The work is focused on the determination of rheological
characteristics of the individual components of polymeric adhesives tested and on
rheological and mechanical properties of the adhesives in the hardening process.
Experiments were performed with one type of single-component adhesive and
three types of two-component adhesives. All the components of PUR adhesives
tested were viscoplastic with a certain degree of yield stress. The respective flow
curves showed a shear-thinning and thixotropic behaviour; the results of
oscillatory tests demonstrating that elastic behaviour dominated for all adhesive
components. The elasticity of an adhesive evidently depended on their mixing
ratio. Finally, it has been found out that adhesive gelation points measured in the
hardening process could be detected much faster at a higher temperature than at
a lower one.