Abstract
This study aims at investigating the degradation mechanism of an automotive clearcoat caused by bird droppings. Natural bird droppings and their synthetic equivalent (pancreatin) were utilized for this purpose. The presence of highly-etched areas on the surface of coatings and structural variations of clearcoat after being attacked by these materials corresponded to a catalyzed hydrolytic degradation. This finding was obtained using different analytical techniques. Based on these studies, three possible hypotheses were presented, including acid catalysis, metal ion catalysis, and enzymatic catalysis. The conditions required for the occurrence of each hypothesis were discussed. It was found that acid and metal ions have a weak contribution to catalyze the hydrolysis reaction of clearcoat, whereas enzymes existing in bird droppings were mainly responsible for this hydrolytic degradation.
This is a preview of subscription content, access via your institution.









References
Nguyen, T, Martin, JW, Byrd, E, Embree, N, “Relating Laboratory and Outdoor Exposure of Coatings III. Effect of Relative Humidity on Moisture-Enhanced Photolysis of Acrylic-Melamine Coatings.” Polym. Degrad. Stab., 77 1–16 (2002)
Yari, H, Moradian, S, Ramezanzadeh, B, Kashani, A, Tahmasebi, N, “The Effect of Basecoat Pigmentation on Mechanical Properties of an Automotive Basecoat/Clearcoat System During Weathering.” Polym. Degrad. Stab., 94 1281–1289 (2009)
Martin, JW, Nguyen, T, Byrd, E, Dickens, B, Embree, N, “Relating Laboratory and Outdoor Exposures of Acrylic Melamine Coatings I. Cumulative Damage Model and Laboratory Exposure Apparatus.” Polym. Degrad. Stab., 75 193–210 (2002)
Yari, H, Mohseni, M, Ramezanzadeh, B, “Comparisons of Weathering Performance of Two Automotive Refinish Coatings: A Case Study.” J. Appl. Polym. Sci., 111 2946–2956 (2009)
Tahmassebi, N, Moradian, S, “Predicting the Performances of Basecoat/Clear Coat Automotive Paint Systems by the Use of Adhesion, Scratch and Mar Resistance Measurements.” Polym. Degrad. Stab., 83 405–410 (2004)
Gerlock, JL, Smith, CA, Cooper, VA, Dusbiber, TG, Weber, WH, “On the Use of Fourier Transform Infrared Spectroscopy and Ultraviolet Spectroscopy to Assess the Weathering Performance of Isolated Clearcoats From Different Chemical Families.” Polym. Degrad. Stab., 62 225–234 (1998)
Stevani, CV, Faria, DLA, Porto, JS, Trindade, DJ, Bechara, JH, “Mechanism of Automotive Clearcoat Damage by Dragonfly Eggs Investigated by Surface Enhanced Raman Scattering.” Polym. Degrad. Stab., 68 61–66 (2000)
PSA PEUGEOT—CITROËN test method D27 5415, “Paint Coatings Resistance to Biological Attacks”
Ramezanzadeh, B, Mohseni, M, Yari, H, “The Role of Basecoat Pigmentation on the Biological Resistance of an Automotive Clearcoat.” J. Coat. Technol. Res., 2010. doi:10.1007/s11998-010-9254-5
Ramezanzadeh, B, Mohseni, M, Yari, H. Sabbaghian, S, “A Study of Thermal-Mechanical Properties of an Automotive Coating Exposed to Natural and Simulated Bird Droppings.” J. Therm. Anal. Calorim. (in press). doi:10.1007/s10973-009-0442-4
Ramezanzadeh, B, Mohseni, M, Yari, H, Sabbaghian, S, “An Evaluation of an Automotive Clear Coat Performance Exposed to Bird Droppings Under Different Testing Approaches.” Prog. Org. Coat., 66 149–160 (2009)
Yari, H, Mohseni, M, Ramazanzade, B, Naderi, N, “Use of Analytical Techniques to Reveal the Influence of Chemical Structure of Clearcoat on Its Biological Degradation Caused by Bird-Droppings.” Prog. Org. Coat., 66 281–290 (2009)
Gaszner, K, Neher-Schmitz, H, Kuntz, T, A Report by Forschungsinstitut for Pigment and Lake eV (FPL), pp. 1–4. Global Automotive Manufacturing & Technology (2003)
Ramazanzade, B, Moradian, S, Yari, H, Kashani, A, Niknahad, M, Chadle, H, Motamed, M, Adeli, M, Shirakbari, N, “The Effect of Basecoat Pigmentation on Weathering Performance of an Acrylic/Melaminebasecoat/Clearcoat Automotive Finishes.” Proceeding of Automotive Adhesive, Sealants and Coatings, Stuttgart, Germany, 2008
Nguyen, T, Martin, JW, Byrd, E, “Relating Laboratory and Outdoor Exposures of Acrylic Melamine Coatings IV. Mode and Mechanism for Hydrolytic Degradation of Acrylic-Melamine Coatings Exposed to Water Vapor in the Absence of Light.” J. Coat. Technol., 75(941) 37–50 (2003)
Bauer, DR, “Degradation of Organic Coatings I. Hydrolysis of Melamine Formaldehyde/Acrylic Copolymer Films.” J. Appl. Polym. Sci., 27 3651–3662 (1982)
Nguyen, T, Martin, J, Byrd, E, Embree, N, “Relating Laboratory and Outdoor Exposure of Coatings II. Effects of Relative Humidity on Photodegradation and the Apparent Quantum Yield of Acrylic Melamine Coatings.” J. Coat. Technol., 74(932) 65–80 (2002)
Mori, K, Tachi, K, Muramatsu, M, Torita, K, “Mechanism of Acid Rain Etching of Acrylic/Melamine Coatings.” Prog. Org. Coat., 36 34–38 (1999)
Schulz, U, Trubiroha, P, Schernau, U, Baumgart, H, “The Effects of Acid Rain on the Appearance of Automotive Paint Systems Studied Outdoors and in a New Artificial Weathering Test.” Prog. Org. Coat., 40 151–165 (2000)
Palm, M, Carlsson, B, “New Accelerated Weathering Tests Including Acid Rains.” J. Coat. Technol., 74(924) 69–74 (2002)
Huang, C, Stone, AT, “Hydrolysis of Naptalam and Structurally Related Amides: Inhibition by Dissolved Metal Ions and Metal (Hydr)Oxide Surfaces.” J. Agric. Food Chem., 47 4425–4434 (1999)
Huang, C, Stone, A, “Synergistic Catalysis of Dimetilan Hydrolysis by Metal Ions and Organic Ligands.” Environ. Sci. Technol., 34 4117–4122 (2000)
Smolen, JM, Stone, AT, “Divalent Metal Ion-Catalyzed Hydrolysis of Phosphorothionate Ester Pesticides and Their Corresponding Oxonates.” Environ. Sci. Technol., 31 1664–1673 (1997)
Zagórowska, I, Kuusela, S, Lönnberg, H, “Metal Ion-Dependent Hydrolysis of RNA Phosphodiester Bonds Within Hairpin Loops. A Comparative Kinetic Study on Chimeric Ribo/24-O-Methylribo Oligonucleotides.” Nucl. Acid Res., 26 3392–3396 (1998)
Brueckner, T, Eberl, A, Heumann, S, Rabe, M, Guebitz, GM, “Enzymatic and Chemical Hydrolysis of Poly(Ethylene Terephthalate) Fabrics.” J. Polym. Sci. A: Polym. Chem., 46 6435–6443 (2008)
Nathalie, V, Lalot, T, Brigodiot, M, Maréchal, E, “Enzyme-Catalyzed Hydrolysis of Unsaturated Polyester Networks. I. Study of the Hydrolysis of a Precursor: Poly(1,2-Propanediyl Fumarate).” J. Polym. Sci. A: Polym. Chem., 35 27–34 (1997)
Nathalie, V, Lalot, T, Brigodiot, M, Maréchal, E, “Enzyme-Catalyzed Hydrolysis of Unsaturated Polyester Networks. II. Enzyme-Catalyzed Hydrolysis of Polyester Networks Prepared From Poly(1,2-Propanediyl Fumarate).” J. Polym. Sci. A: Polym. Chem., 35 35–40 (1997)
Calil, MR, Gaboardi, F, Bardi, MAG, Rezende, ML, Rosa, DS, “Enzymatic Degradation of Poly(e-Caprolactone) and Cellulose Acetate Blends by Lipase and α-Amylase.” Polym. Test., 26 257–261 (2007)
Xi, Z, Yoshida, T, Funaoka, M, “Enzymatic Degradation of Highly Phenolic Lignin-Based Polymers (Lignophenols).” Eur. Polym. J., 39 909–914 (2003)
Montaudo, G, Rizzarelli, P, “Synthesis and Enzymatic Degradation of Aliphatic Copolyesters.” Polym. Degrad. Stab., 70 305–314 (2000)
Kurokawa, K, Yamashita, K, Doi, Y, Abe, H, “Surface Properties and Enzymatic Degradation of End-Capped Poly(L-Lactide).” Polym. Degrad. Stab., 91 1300–1310 (2006)
Sangaj, S, Malshe, VC, “Permeability of Polymers in Protective Organic Coatings.” Prog. Org. Coat., 50 28–39 (2004)
Nielsen, AD, Fuglsang, CC, Westh, P, “Effect of Calcium Ions on the Irreversible Denaturation of a Recombinant Bacillus halmapalus α-Amylase: A Calorimetric Investigation.” Biochem. J., 373 337–343 (2003)
Polaina, J, MacCabe, AP, Industrial Enzymes: Structure Function and Applications. Springer, Netheralnds (2007)
Schandl, A, Pittner, F, “The Role of Na+ and Ca2+ Ions on the Action of Pancreatic Lipase Studied with the Help of Immobilisation Techniques.” Eur. J. Biochem., 140 547–551 (1984)
Deegan, RD, Bakajin, O, Dupont, TF, Huber, G, Nagel, S, Witten, TA, “Capillary Flow as the Cause of Ring Stains from Dried Liquid Drops.” Nature, 389 827–829 (1997)
Ratner, B, Haffman, AS, Schoen, FJ, Lemons, JE, Biomaterials Science. An Introduction to Materials in Medicine, 1st ed. Academic press, New York (1997)
Acknowledgment
The authors thank the Iran Khodro Co., for providing the coating samples.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Yari, H., Mohseni, M. & Ramezanzadeh, B. A mechanistic study of degradation of a typical automotive clearcoat caused by bird droppings. J Coat Technol Res 8, 83–95 (2011). https://doi.org/10.1007/s11998-010-9273-2
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11998-010-9273-2