Work of fragmentation of a thin oxide coating on a polymer film

摘要

Thin oxide coatings adhering on polymer films have experienced considerable development for a large variety of applications, ranging from food packaging to microelectronics. In these applications, the reliability of the materials is mainly determined by the coating integrity and the polymer/coating adhesion. Among the numerous tests available to characterize adhesion [1], the fragmentation technique was found particularly suitable in the case of silicon oxide coatings on poly(ethylene terephtha-late) (PET) substrates [2]. In the fragmentation test, the coated material is strained in uniaxial tension, and the development of the crack pattern is analysed as a function of applied strain. The method allows derivation of the cohesive and adhesive strengths and the thermodynamic work of adhesion [2, 3], which makes the technique a powerful tool for interfacial characterization, providing that only a small amount of delamination develops during the straining process.