High Adhesive Force between Laminated Sheets of Titanium and Polyurethane Improved by Homogeneous Low Energy Electron Beam Irradiation Prior to Hot-Press

摘要

2-layer Titanium/Polyurethane (Ti/PU) laminated sheets were prepared by a new adhesion method, a double-step treatment consisting of applying low dose (<= 0.43 MGy) homogeneous low energy electron beam irradiation (HLEBI) prior to hot-press under 5 MPa and 413 K. Although the weak hot-press adhesion of the Ti/PU was observed without HLEBI, the new adhesion raised the bonding forces as evidenced by the mean adhesive forces of peeling resistance (F-o(p)). Based on the 3-parameter Weibull equation, the lowest F-o(p) value at peeling probability (P-p) of zero (F-s) could be estimated. An increasing trend in F-s occurred by the double-step treatment applying HLEBI up to 0.22 MGy reaching a maximum at 123 Nm(-1), improving the safety level without radiation damage. XPS (X-Ray Photoelectron Spectroscopy) observations of the peeled 0.22 MGy irradiated Ti revealed generation of a TiO2 peak at 530.6 eV possibly explaining the increased adhesion. The residual PU deposition is apparently found to be retained on the Ti sheet by inter-matrix fracture of PU further into the thickness. This can be explained by the adhesion force between Ti/PU being stronger than the cohesive force of PU polymer itself.