Evaluation of Surface Viscoelastic Properties for Pressure Sensitive Adhesives Using Force Measurement of Atomic Force Microscope

摘要

The understanding of properties of polymer surface is crucial for the development of new applications in area such as adhesion, wetting and friction. Precise quantitative surface mechanical characterizations have been a long-standing academic and technological challenge. Atomic force microscopy is a tool that analyzes surface nano-mechanical properties and the interaction force between a probe and polymer surface. The Hertz theory is frequently used for analyzing force-distance curves. But we could not obtain precise Young's modulus for pressure sensitive adhesives (PSA) with the Hertz theory because the adhesive interaction could not be neglected. Johnson-Kendall-Roberts (JKR) contact mechanics is used as the most appropriate solution of the actual contact between AFM probe tip and sample surface. It is possible to obtain precise Young's modulus (E) and adhesive energy (w) simultaneously by JKR-based two point method.