Surface Modification of a Polyurethane Film by Low Pressure Nitrogen Plasma for Improved Adhesion to Polyethylene Foam for Automotive Industry Laminates

A low pressure glow discharge nitrogen plasma has been used to modify wettability of a polyurethane film and, consequently, improve adhesion properties to polyolefin foam in order to obtain technical laminates for uses in automotive industry. A significant increase in surface wettability is achieved after the plasma treatment as observed by contact angle measurements. Surface changes have been studied by X-ray photoelectron spectroscopy (insertion of polar groups) and atomic force microscopy (changes in surface roughness and topography). Laminates based on plasma-treated polyurethane film and polyolefin foam show a considerable increase in the T-peel strength of the adhesion joint; furthermore we can observe a slight ageing process under aggressive conditions (high temperature and relative humidity).