Tackiness of pressure-sensitive adhesives: An ultra-small-angle X-ray scattering investigation
Abstract
The debonding of a model pressure-sensitive adhesive (PSA) poly-n-buthylacrylate is investigated by a combination of the mechanical tack test, optical microscopy and in situ ultra-small-angle X-ray scattering. From the mechanical test, macroscopic values such as force-distance curves are determined. The force-distance curve exhibits the typical non-linear behavior. With microscopy the macroscopic cavitation structure is observed. Scattering addresses the structure of the PSA on a microscopic level for the first time. As a new feature, a sub-structure of the usual optically resolvable macroscopic fibrils between the PSA surface and the probe punch is detected. The sub-structure exists over a large distance between the PSA and the probe surface and remains constant in diameter. This behavior of the sub-structure as well as the dependence of the force plateau on the film thickness are compared with theoretical predictions.
- Publication:
-
EPL (Europhysics Letters)
- Pub Date:
- May 2004
- DOI:
- 10.1209/epl/i2003-10231-y
- Bibcode:
- 2004EL.....66..513M