Nanostructured polyurethane ceramer coatings for aircraft
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A new low VOC (volatile organic compounds) polyurethane/oligosiloxane coating was formulated using 1,6-hexamethylene diisocyanate (HDI) isocyanurate, alkoxysilane-functionalized HDI isocyanurate, tetraethyl orthosilicate (TEOS) oligomers, and three cycloaliphatic polyesters. One series of polyesters was synthesized using 1,4-cyclohexanedimethanol (CHDM) with 1,4-cyclohexanedicarboxylic acid (1,4-CHDA) and 1,3-cyclohexanedicarboxylic acid (1,3-CHDA). A second series of polyesters was synthesized using 2-butyl-2-ethyl-1,3-propanediol (BEPD) with 1,4-CHDA or 1,4-CHDA, and 1,3-CHDA, respectively. The polyurethane provided the general mechanical properties and the polysiloxane functioned as an adhesion promoter and corrosion inhibitor. The continuous organic polyurethane phase was coupled with the inorganic polysiloxane phase via the alkoxysilane-functionalized HDI isocyanurate. The general coatings, tensile, and viscoelastic properties were evaluated for the ceramer coatings as functions of the polyester and concentration of TEOS oligomers. Damage tolerance was evaluated via fracture toughness and development of the film deformation zone prior to crack propagation. The coatings’ properties were dominated by the organic phase. The film morphology was investigated using the combination of SEM (scanning electron microscope) and X-ray analysis. Phase separation was observed for ceramer coatings resulting in SiO2 particles. The size of the preceramic silicon-oxo-particles was controlled by the Tg of the organic phase and the concentration of TEOS oligomers.
KeywordsFracture Toughness Polyurethane Isocyanurate Ceramer Coating Coating Technology
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- (1).Chattopadhyay, A.K. and Zenter, M.R., “Aerospace and Aircraft Coatings,”Federation Series on Coatings Technology, Federation of Societies for Coatings Technology, Philadelphia, PA, 1990.Google Scholar
- (3).Hegedus, C.R., Pulley, D.F., Spadafora, S.J.B., Eng, A.T., and Hirst, D.J., “A Review of Organic Coating Technology for U.S. Naval Aircraft,”Journal of Coatings Technology,61, No. 778, 31 (1989).Google Scholar
- (4).Child, T. and Van Ooij, W.J.Coat. World, 4 (3), 42 (1999).Google Scholar
- (6).Witucki, G.L., “A Silane Primer: Chemistry and Applications of Alkoxy Silanes,”Journal of Coatings Technology,65, No. 822, 57 (1993).Google Scholar
- (7).Brinker, C.J. and Scherer, G.W.,Sol-Gel Science, Chapter 14, p. 849, Academic, New York, 1990.Google Scholar
- (8).Berger, D.M.,Metal Finishing, 77 (4), 27 (1979).Google Scholar
- (13).Ni, H., Skaja, A.D., Sailer, R.A., and Soucek, M.D.,Polym. Prepr., Am. Chem. Soc., Div. Polym. Chem., 39 (1), 367, 1998.Google Scholar
- (14).Ni, H., Skaja, A.D., Sailer, R.A., and Soucek, M.D.,Polym. Mater. Sci. Eng., Am. Chem. Soc., Div. Polym. Mater. Sci. Eng., 79, 21, 1998.Google Scholar
- (17).Johnson, L.K. and Sade, W.T., “New Monomers for Polyester Powder Coating Resins,”Journal of Coatings Technology,65, No. 826, 19 (1993).Google Scholar
- (18).Heidt, P.C. “Cycloaliphatic-Based Thermoset Industrial Coatings,” Waterborne, Higher-Solids, and Power Coatings Symposium, sponsored by The University of Southern Mississippi, New Orleans, LA, February 9–11, 1994.Google Scholar
- (19).Eastman Publication N-341A.Google Scholar
- (20).Eastman Publication N-335A.Google Scholar
- (21).Eastman Publication N-327A.Google Scholar
- (22).Williams, J.G.,Fracture Mechanics of Polymers, John Wiley & Sons, New York, 1987.Google Scholar
- (25).Tuman, S.J. and Soucek, M.D., “Novel Inorganic/Organic Coatings Based on Linseed Oil and Sunflower Oil with Sol-Gel Precursors,”Journal of Coatings Technology,68, No. 854, 73 (1996).Google Scholar
- (26) (a).
- (26) (b).