Surface Energy Modification by Radiofrequency Inductive and Capacitive Plasmas at Low Pressures on Sugar Maple: An Exploratory Study
Keywords:Surface energy surface properties, plasma, adhesion, sugar maple, wettability, ICP, CCP, mechanical properties, wood, confocal Raman spectroscopy, XPS
AbstractThe wood products industry is going through hard times in both Canada and the US. It is faced with competition from emerging economies and substitution products. The North American economy is slowing down with decreasing demand for wood products. Under these conditions, the industry should be innovative and develop the next generation of wood products. Plasma technology could be used to improve wood surface properties and compensate for the variations to be expected from an organic living material, which is sensitive to its environment (moisture, water, temperature, ultraviolet light). In recent years, the plastic and textile industries have begun experimenting with plasma technology to activate surfaces, mainly to improve coating/substrate adhesion. The literature on potential applications of plasma treatment to wood surfaces is very limited. This report describes the results of an exploratory study on the effect of plasma treatments on sugar maple wood using different gases and mixtures (N2, H2, O2, and Ar) at different pressures (13.3-665 Pa). Water wettability and adhesion between surface and waterborne polyurethane acrylate coatings were also studied. The results show that it was possible, under certain conditions, to significantly increase wood/coating adhesion by 30-100%. This improvement is correlated with improvements in wood surface energy and coating penetration depth. In addition, chemical analyses showed that, with some plasma types, the treatment led to new atoms being grafted.
Anon (1999) Wood handbook—Wood as an engineering material. Gen Tech Rep FPL-GTR-113. USDA For Serv Forest Products Laboratory, Madison, WI. 463 pp.nASTM (2002) ASTM D4541-2, standard test method for pull-off strength of coatings using portable adhesion testers. American Society for Testing and Materials, West Conshohocken, PAnBlanchard V, Riedl B, Blanchet P, Evans P (2009) Sugar maple wood board surface modification by plasma treatments at low pressure, in Proc Sixth International Symposium on Contact Angle, Wettability and Adhesion, K. L. Mittal, ed., 14-16 July 2008, Orono, ME.nBlantocas GQ, Manteum PER, Odille RWM, Ramos RJU, Monasterial JLC, Ramos HJ, Bo-ot LM (2007) Inhibited flammability and surface inactivation of wood irradiated by low energy hydrogen ion showers (LEHIS). Nucl Instrum Meth B 259:875-883.nCastell P, Wouters M, Fischer H, De With G (2007) Study of wettability and improvement of adhesion of UV curable powder coatings on polypropylene substrates. J Appl Polym Sci 5:3348-3358.nChen H, Zavarin E (1990) Interactions of cold radiofrequency plasma with solid wood. J Wood Chem Technol 10:387-400.nCollett BM (1972) A review of surface and interfacial adhesion in wood science and related fields. Wood Sci Technol 6:1-42.nConrads H, Schmidt M (2000) Plasma generation and plasma sources. Plasma Sources Sci Technol 9:441-545.nDe Meijer M, Militz H (1998) Wet adhesion measurements of wood coatings. Holz Roh Werkst 56:306.nDenez FS, Cruz-Barba LE, Manolache S (2005) Handbook of wood chemistry and wood composites. Pages 447-474 in RM Rowell, ed. Taylor and Francis, Boca Raton, FL.nElbez G, Bentz D (1991) Le collage du bois [Wood gluing]. CTBA, Paris, France. 215 pp.nEvans PD, Ramos M, Senden T (2007) Modification of wood using a glow-discharge plasma derived from water. Pages 123-133 in CAS Hill, D Jones, H Militz, GA Ormondro, eds. European Conference on Wood Modification, 15-16 October, Wales, UK.nHuntsberger JR (1963) The relationship between wetting and adhesion. Pages 180-188 in Kendall Award Symposium, 2-3 April, Los Angeles, CA.nHuntsberger JR (1967) The mechanisms of adhesion. Pages 119-149 in RL Patrick, ed. Treatise on adhesion and adhesives. Marcel Dekker, New York, NY.nKim BS, Chun BH, Lee WI, Hwang BS (2009) Effect of plasma treatment on the wood flour/PP composites. J Thermoplast Compos 22(1):21-28.nLewis AF, Forrestal LJ (1969) Adhesion of coatings. Pages 57-98 in Treatise on coatings. Marcel Dekker, New York, NY.nLieberman MA, Lichtenberg AJ (1994) Principles of plasma discharges and materials processing. John Wiley & Sons, New York, NY.nLipska-Quinn AE (1994) The effect of RF plasma on the chemical and physical properties of wood. PhD Thesis, University of California, Berkeley, CA.nLiptáková E, Kúdela J (1994) Analysis of the wood-wetting process. Holzforschung 48:139-144.nMagalhães WLF, Souza MF (2002) Solid softwood coated with plasma-polymer for water repellence. Surf Coat Tech 155:11-15.nManolache S, Jiang H, Rowell RM, Denes FS (2008) Hydrophobic wood surfaces generated by non-equilibrium, atmospheric pressure (NEAPP) plasma-enhanced coating. Mol Cryst Liq Cryst 483:348-351.nPodgorski L, Boustas C, Schambourg F, Maguin J, Chevet B (2002) Surface modification of wood by plasma polymerization. Pigm Resin Technol 31(1):33-40.nPodgorski L, Chevet B, Onic L, Merlin A (2000) Modification of wood wettability by plasma and corona treatments. Int J Adhes Adhes 20:102-111.nRehn P, Wolkenhauer A, Bente M, Forster S, Viol W (2003) Wood surface modification in dielectric barrier discharges at atmospheric pressure. Surf Technol 174:515-518.nSharpe LH, Schonhorn H (1963) Surface energetics, adhesion, and adhesive joints. Pages 189-201 in Kendall Award Symposium, 2-3 April, Los Angeles, CA.nTendro C, Tixier C, Tristant P, Desmaison J, Leprince P (2006) Atmospheric pressure plasmas: A review. Atom Spectrosc 61:2-30.nVasishth RC, Giltrow FR, Koran Z (1974) SEM studies of weathered varnish on wood. Wood Sci 6:278-284.nWolkenhauer A, Avramidis G, Cai Y, Militz H, Viöl W (2007) Investigation of wood and timber surface modification by dielectric barrier discharge at atmospheric pressure. Plasma Process Polym 4:470-474.nWolkenhauer A, Avramidis G, Hauswald E, Militz H, Viöl W (2009) Sanding vs plasma treatment of aged wood: A comparison with respect to surface energy. Int J Adhes Adhes 29:18-22.nWolkenhauer A, Militz H, Viöl W (2008) Plasma treatment of heat treated beech wood investigation on surface free energy. Holzforschung 62(4):472-474.nWolkenhauer A, Militz H, Viöl W (2008) Increased PVA-glue adhesion on particle board and fibre board by plasma treatment. Holz Roh Werkst 66:143-145.nYang XK, Du GB, Quan TC, Yang XY, Wang TD, Zhang J (2004) XPS studies on microwave plasma modifications of wood surfaces in Proc 31st International Conference on Plasma Science, 28 June -1 July, Baltimore, MD.n
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