Overcoming oxygen inhibition in UV-curing of acrylate coatings by carbon dioxide inerting, Part I

• Published in: Progress in organic coatings Vol. 48; no. 1; pp. 92 - 100
• Main Authors: Studer, Katia, Decker, Christian, Beck, Erich, Schwalm, Reinhold
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.11.2003; Elsevier Sequoia
• Subjects: Acrylate coatings; Applied sciences; Carbon dioxide inerting; Coatings. Paints, varnishes and inks; Components, formulation; Exact sciences and technology; Oxygen inhibition; Photopolymerization; Polymer industry, paints, wood; Oxygen inhibition; Carbon dioxide inerting; Photopolymerization; Acrylate coatings; Oxygen molecules; Free radical polymerization; Coating material; Acrylate polymer; Conversion rate; Formulation; Carbon dioxide; Reaction inhibition; Kinetic parameter; Binders
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/S0300-9440(03)00120-6

The inhibitory effect of molecular oxygen in the photoinitiated polymerization of acrylate resins has been completely eliminated by operating in a carbon dioxide atmosphere. The high speed polymerization was followed in situ by real time infrared spectroscopy, thus allowing conversion versus time curves to be recorded for curing reactions occurring within a fraction of a second. The influence of the O 2 concentration and of the sample temperature on the polymerization kinetics has been quantified for a polyurethane-acrylate resin. Replacing air by CO 2 proved to be particularly beneficial for polymerizations carried out under conditions where O 2 diffusion was enhanced, i.e. thin films of a highly fluid resin exposed to low intensity light at high temperatures.