Durable anti-fogging effect and adhesion improvement on polymer surfaces

¹ hepia Geneva, University of Applied Sciences Western Switzerland, 4 rue de la Prairie, 1202 Geneva, Switzerland
² Institut Jean Lamour, UMR CNRS – Nancy Université – UPV-Metz, Département Chimie et Physique des Solides et des Surfaces, École des Mines, Parc de Saurupt, CS14234, 54042 Nancy, France

Corresponding author: eva-maria.moser@hesge.ch

Received: 30 June 2009
Revised: 28 October 2009
Accepted: 6 November 2009
Published online: 11 December 2009

Abstract

The hydrophobic properties of polymeric surfaces may cause fogging in transparent packaging and poor adhesion to printing colours and coatings. Novel plasma processes for durable functionalization of polypropylene and polyethylene terephthalate substrates were developed and analysed using optical emission spectroscopy. A worm-like nano pattern was created on the polypropylene surface prior to the deposition of thin polar plasma polymerised layers. For both substrates, highly polar surfaces exhibiting a surface tension of up to 69 mN/m and a water contact angle of about 10° were produced – providing the anti-fogging effect. The deposition of thin plasma polymerised layers protects the increased surface areas and enables to tailoring the surface energy of the substrate in a wide range. Wetting characteristics were determined by dynamic contact angle measurements. Investigations of the chemical composition of several layers using X-ray photoelectron spectroscopy and FT-infrared spectroscopy were correlated with functional testing. The surface topography was investigated using atomic force microscopy. The weldability and peeling-off characteristics of the plasma treated polymer films could be adjusted by varying the process parameters. Global and specific migration analyses were undertaken in order to ensure the manufacturing of plasma treated polymer surfaces for direct food contact purposes.