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Interdiffusion and crosslinking in thermoset latex films

  • Technical Articles
  • Published:
Journal of Coatings Technology

Abstract

Thermoset latex systems represent an attractive approach to obtaining the high performance needed in many different kinds of industrial coatings, while satisfying the growing requirement for environmental friendliness. In these coatings in the dispersed state, the reactive groups are packaged inside of polymer particles. These latex particles deform as the coating dries to form a transparent binder phase. The useful properties of mechanical strength, as well as scrub and solvent resistance, develop over time. This paper focuses on the idea that to achieve the desired properties in a thermoset latex coating, one has to pay proper attention to the relative rates of polymer diffusion and crosslinking in the coating. Strength in these films develops as a consequence of chains that connect crosslink points on opposite sides of interface formed between adjacent particles in the film. Thus polymer diffusion must precede extensive bond formation created by the crosslinking chemistry. This paper reviews fundamental concepts and then describes experiments in three separate systems. These experiments show that the formulator has three main strategies to vary the relative rates of these processes: 1. Catalyst strength and concentration will affect the reaction rate. 2. Polymer chain length will affect the polymer diffusion rate. 3. Temperature changes will normally have a larger affect on the polymer diffusion rate than on the crosslinking reaction rate.

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References

  1. Taylor, J.W. and Winnik, M.A., “Functional Latex and Thermoset Latex Films,” to be published.

  2. Bufkin, B.G. and Grawe, J.R., “Survey of the Applications, Properties, and Technology of Crosslinking Emulsions Part I,”Journal of Coatings Technology,50, No. 641, 41–55 (1978);

    CAS  Google Scholar 

  3. Grawe, J.R. and Bufkin, B.G., “Survey of the Applications, Properties, and Technology of Crosslinking Emulsions Part II,”Journal of Coatings Technology,50, No. 643, 67–83 (1978);

    CAS  Google Scholar 

  4. Bufkin, B.G. and Grawe, J.R., “Survey of the Applications, Properties, and Technology of Crosslinking Emulsions Part III,”Journal of Coatings Technology,50, No. 644, 83–109 (1978);

    CAS  Google Scholar 

  5. Grawe, J.R. and Bufkin, B.G., “Survey of the Applications, Properties, and Technology of Crosslinking Emulsions Part IV,”Journal of Coatings Technology,50, No. 645, 70–100 (1978);

    CAS  Google Scholar 

  6. Bufkin, B.G. and Grawe, J.R., “Survey of the Applications, Properties, and Technology of Crosslinking Emulsions Part V,”Journal of Coatings Technology,50, No. 647, 65–96 (1978);

    CAS  Google Scholar 

  7. Grawe, J.R. and Bufkin, B.G., “Survey of the Applications, Properties, and Technology of Crosslinking Emulsions Part VI,”Journal of Coatings Technology,51, No. 649, 34–67 (1978);

    Google Scholar 

  8. Yeliseeva, V. I. “Crosslinking of Latex Polymers,”Br. Polym. J., 7, 33–49 (1975).

    Article  Google Scholar 

  9. Winnik, M.A., “Latex Film Formation,”Curr. Op. Coll. Interfac. Sci., 2, 192–199 (1997);

    Article  CAS  Google Scholar 

  10. Winnik, M.A., “The Formation and Properties of Latex Films,” inEmulsion Polymerization and Emulsion Polymers, Lovell, P. and El-Aasser, M.S. (Eds.), Ch. 14, 467–518, 1997;

  11. Keddie, J.L., “Film Formation of Latex,”Mat. Sci. Eng., 21, 101–170 (1997);

    Article  Google Scholar 

  12. Provder, T., Winnik, M.A., and Urban, M.W. (Eds.), “Film Formation in Waterborne Coatings,”ACS Symp. Ser. 648, Amer. Chem. Soc., Washington, D.C., 1996.

    Google Scholar 

  13. Zosel, A. and Ley, G., “Influence of Crosslinking on Structure, Mechanical Properties and Strength of Latex Films,”Macromolecules, 26, 2222–2227 (1993);

    Article  ADS  CAS  Google Scholar 

  14. Tamai, T., Pinenq, P., and Winnik, M.A., “Effect of Crosslinking on Polymer Diffusion in Poly(butyl methacrylate-co-butyl acrylate) Latex Films,”Macromolecules, 32, 6102–6110 (1999).

    Article  ADS  CAS  Google Scholar 

  15. Doi, M. and Edwards, S.F.,The Theory of Polymer Dynamics, Oxford University Press, Oxford, England, 1986.

    Google Scholar 

  16. de Gennes, P.G.,Scaling Concepts in Polymer Physics, Cornell University Press, Ithaca, NY, 1979.

    Google Scholar 

  17. de Gennes, P.G. “Couples de Polymères Compatibles: Propriétés Spéciales en Diffusion et en Adhésion,”C. R. Seances Acad. Sci., Ser. 2, 292, 1505–1507 (1981);

    Google Scholar 

  18. de Gennes, P.G., “Dynamics of Fluctuations and Spinodal Decomposition in Polymer Blends,”J. Chem. Phys., 72, 4756–4763 (1980);

    Article  MATH  ADS  MathSciNet  Google Scholar 

  19. de Gennes, P.G. “Tension Superficielle des Polymères Fondus,”C. R. Acad. Sci., Ser. 2, 307, 1841–1844, 1988.

    Google Scholar 

  20. Prager, S. and Tirrell, M., “The Healing Process at Polymer-Polymer Interfaces,”J. Chem. Phys., 5194–5198 (1981).

  21. Wool, R.P. and O’Connor, K.M., “A Theory of Crack Healing in Polymers,”J. Appl. Phys., 52, 5953–5963 (1981);

    Article  ADS  CAS  Google Scholar 

  22. Wool, R.P. and O’Connor, K.M., “Time Dependence of Crack Healing,”J. Polym. Sci., Polym. Lett. Ed., 20, 7–16 (1982).

    Article  CAS  Google Scholar 

  23. Wool, R.P.,Polymer Interfaces, Hanser Publishers, 1995.

  24. Crank, J.,The Mathematics of Diffusion, Clarendon, Oxford, U.K., 1975.

    Google Scholar 

  25. Ferry, J.D.,Viscoelastic Properties of Polymers, 3rd ed, Wiley, New York, Chapter 11, 1980.

    Google Scholar 

  26. Nemoto, N., Landry, M.R., Nob, I., and Yu, H., “Temperature Dependence of the Self Diffusion Coefficient of Polyisoprene in the Bulk State,”Polymer Commun., 25, 141–143 (1984);

    CAS  Google Scholar 

  27. Chen, S.J. and Ferry, J.D., “The Diffusion of Radioactively Tagged n-Hexadecane and n-Dodecane Through Rubbery Polymers. Effects of Temperature, Crosslinking and Chemical Structure,”Macromolecules, 1, 270–278 (1968).

    Article  ADS  CAS  Google Scholar 

  28. Birks, J.B.,Photophysics of Aromatic Molecules, Wiley-Interscience, London, 1970.

    Google Scholar 

  29. Liu, Y.S., Feng, J., and Winnik, M.A., “Study of Polymer Diffusion Across the Interface in Latex Films Through Direct Energy Transfer Experiments,”J. Chem. Phys., 101, 9096–9103 (1994);

    Article  ADS  CAS  Google Scholar 

  30. Winnik, M.A., Li, L., and Liu, Y.S., “Fluorescence Decay Studies of Polymer Diffusion Across Interfaces in Latex Films,” inMicrochemistry: Spectroscopy and Chemistry in Small Domains, Masuhara, H. and Kitamura, N. (Eds.), Elsevier, Holland, pp. 387–400, (1994);

    Google Scholar 

  31. Dhinojwala, A. and Torkelson, J.M., “A Reconsideration of the Measurement of Polymer Interdiffusion by Fluorescence Nonradiative Energy Transfer,”Macromolecules, 27, 4817–4824 (1994).

    Article  ADS  CAS  Google Scholar 

  32. Kim, H.-B. and Winnik, M.A., “Factors Affecting Interdiffusion Rates in Films Prepared from Latex Particles with a Surface Rich in Acid Groups and Their Salts,”Macromolecules, 28, 2033–2041 (1995).

    Article  ADS  CAS  Google Scholar 

  33. Yekta, A., Duhamel, J., and Winnik, M.A., “Dipole-Dipole Electronic Energy Transfer. Fluorescence Decay Functions for Arbitrary Distributions of Donors and Acceptors: Systems With Planar Geometry,”Chem. Phys. Lett., 235, 119–125 (1995).

    Article  ADS  CAS  Google Scholar 

  34. Farinha, J.P.S., Martinho, J.M.G., Yekta, A., and Winnik, M.A., “Direct Nonradiative Energy Transfer in Polymer Interphases: Fluorescence Decay Functions from Concentration Profiles Generated by Fickian Diffusion,”Macromolecules, 28, 6084–6088 (1995).

    Article  ADS  CAS  Google Scholar 

  35. Winnik, M.A., Wang, Y., and Haley, F., “Latex Film Formation at the Molecular Level: The Effect of Coalescing Aids on Polymer Diffusion,”Journal of Coatings Technology,64, No. 811, 51–61 (1992);

    CAS  Google Scholar 

  36. Wang, Y. and Winnik, M.A., “Polymer Diffusion Across Interfaces in Latex Films,”J. Phys. Chem. 97, 2507–2515 (1993);

    Article  CAS  Google Scholar 

  37. Goh, M.C., Juhué, D., Leung, O.-M., Wang, Y., and Winnik, M.A., “Annealing Effects on the Surface Structure of Latex Films Studied by Atomic Force Microscopy,”Langmuir, 9, 1319–1322 (1993);

    Article  CAS  Google Scholar 

  38. Kim, H.-B., Wang, Y., and Winnik, M.A., “Synthesis, Structure and Film-Forming Properties of Poly(butyl methacrylate)-poly(methacrylic acid) Core-Shell Latex,”Polymer, 35, 1779–1786 (1994);

    Article  CAS  Google Scholar 

  39. Winnik, M.A. and Liu, Y.S., “Direct Non-Radiative Energy Transfer Studies of Interdiffusion Latex Films: Strategies for Data Analysis,”Makromol. Symp., 92, 321–331 (1995);

    CAS  Google Scholar 

  40. Feng, J., Winnik, M.A., Shivers, R.R., and Clubb, B., “Polymer Blend Latex Films: Morphology and Transparency,”Macromolecules, 28, 7671–7682 (1995);

    Article  ADS  CAS  Google Scholar 

  41. Winnik, M.A. and Feng, J., “Latex Blends: An Approach to Zero VOC Coatings,”Journal of Coatings Technology,68, No. 852, 39–50 (1996);

    Google Scholar 

  42. Farinha, J.P.S., Martinho, J.M.G., Kawaguchi, S., Yekta, A., and Winnik, M.A., “Latex Film Formation Probed by Nonradiative Energy Transfer: Effect of Grafted and Free Poly(ethylene oxide) on a Poly(n-butyl methacrylate) Latex,”J. Phys. Chem., 100, 12552–12558 (1996);

    Article  Google Scholar 

  43. Feng, J., Winnik, M.A., and Siemiarczuk, A., “Interface Characterization in Latex Blend Films by Fluorescence Energy Transfer,”J. Polym. Sci: Part B: Polym. Phys., 36, 1115–1128 (1998);

    Article  CAS  ADS  Google Scholar 

  44. Feng, J., Pham, H., Stoeva, V., and Winnik, M.A., “Polymer Diffusion in Latex Films at Ambient Temperature,”J. Polym. Sci.: Part B: Polym. Phys., 36, 1129–1139 (1998);

    Article  CAS  ADS  Google Scholar 

  45. Feng, J., Odrobina, E., and Winnik, M.A., “Effect of Hard Polymer Filler Particles on Polymer Diffusion in a Low-T8 Latex Film,”Macromolecules, 31, 5290–5299 (1998);

    Article  ADS  CAS  Google Scholar 

  46. Odrobina, E., Feng, J., and Winnik, M.A., “Effect of Oligomers on the Polymer Diffusion Rate in Poly(butyl methacrylate) Latex Films.,”J. Polym. Sci. Part A: Polym. Chem., 39, 3933–3943 (2000).

    Article  ADS  Google Scholar 

  47. Boczar, E.M., Dionne, B.C., Fu, Z., Kirk, A.B., Lesko, P.M., and Koller, A.D., “Spectroscopic Studies of Polymer Inter-Diffusion During Film Formation,”Macromolecules, 28, 5772–5781 (1993).

    Article  ADS  Google Scholar 

  48. Juhué, D. and Lang, J., “Film Formation from Dispersion of Core-Shell Latex Particles,”Macromolecules, 28, 1306–1308 (1995).

    Article  ADS  Google Scholar 

  49. Feng, J., Pham, H., Macdonald, P., Winnik, M.A., Geurts, J.M., Zirkzee, H., van Es, S., and German, A.L., “Formation and Crosslinking of Latex Films through the Reaction of Acetoacetoxy Groups with Diamines under Ambient Conditions,”Journal of Coatings Technology,70, No. 881, 57–68 (1998).

    Article  CAS  Google Scholar 

  50. Liu, R., Winnik, M.A., DiStefano, F., and Vanketessan, J., “Interdiffusion vs. Crosslinking Rates in Isobutoxyacrylamide-Containing Latex Coatings,”Macromolecules, 34, 7306–7314 (2001).

    Article  ADS  CAS  Google Scholar 

  51. The value of 38 kcal/mol we obtained for experiments in the range of 70 to 100°C were essentially identical to that obtained by the Ferry group from dynamic mechanical measurements on PBMA (37 kcal/mol at 100°C): Child, W.C. and Ferry, J.D., “Dynamic Mechanical Properties of Poly(butyl methacrylate),”J. Colloid Sci., 12, 327–341 (1957);

    Article  CAS  Google Scholar 

  52. Ferry, J.D. and Strella, S., “Dielectric Dispersion of Methacrylate Polymers and Its Correlation with Mechanical Properties,”J. Colloid Sci., 13, 459–471 (1958).

    Article  CAS  Google Scholar 

  53. Wang, Y. and Winnik, M.A., “Energy-Transfer Study of Polymer Diffusion in Melt-Pressed Films of Poly(methyl methacrylate),”Macromolecules, 26, 3147–3150 (1993).

    Article  ADS  CAS  Google Scholar 

  54. Winnik, M.A., Pinenq, P., Krüger, C., Zhang, J., and Yaneff, P.V., “Crosslinking vs. Interdiffusion Rates in Melamine-Formaldehyde Cured Latex Coatings: A Model for Waterborne Automotive Basecoat,”Journal of Coatings Technology,71, No. 892, 47–60 (1999).

    Article  CAS  Google Scholar 

  55. Hahn, K.G., Thermosetting Acrylic Latexes, U.S. Patent 4,812,491 (1989);

  56. Kunz, B.L. and Hahn, K.G., Pigmented Low Cure Emulsion Polymers, U.S. Patent 4,981,883 (1991).

  57. Taylor, J.W., “A Study on the Chemistry of Alkylcarbodiimide Ethyl Methacrylates as Reactive Monomers for Acrylic and Vinyl Ester-based Latexes,”Proc. XXIVth International Conference in Organic Coatings Science and Technology, Athens, Greece, (1995);

  58. Taylor, J.W., Collins, M.-J., and Bassett, D.R., “A Study on the Chemistry of Alkylcarbodiimide Ethyl Methacrylates as Reactive Monomers for Acrylic and Vinyl Ester-based Latexes,”Prog. Org. Coat., 35, 215–221 (1999).

    Article  CAS  Google Scholar 

  59. Pham, H.H. “Polymer Interdiffusion vs. Crosslinking in Carboxylic Acid-Carbodiimide Latex Films,” Ph.D. Thesis, University of Toronto, 1999.

  60. Pham, H.H. and Winnik, M.A., “Synthesis, Characterization, and Stability of Carbodiimide Groups in Carbodiimide-Functionalized Latex Dispersions and Films,”J. Polym. Sci. Part A, Polym. Chem., 38, 855–869 (2000).

    Article  CAS  ADS  Google Scholar 

  61. Pham, H.H., Farinha, J.P.S., and Winnik, M.A., “Crosslinking, Miscibility, and Interface Structure in Blends of Poly(2-Ethylhexyl Methacrylate) Copolymers. An Energy Transfer Study,”Macromolecules, 33, 5850–5862 (2000);

    Article  ADS  CAS  Google Scholar 

  62. Pham, H.H. and Winnik, M.A., “Film Formation from Blends of Carbodiimide and Carboxylic Acid-Functional Latex,” inFilm Formation in Coatings, Provder, T., Urban, M.W. (Eds.), ACS Symposium Series 790, Chapter 5, pp. 88–102, Washington, D.C. (2001).

  63. Pham, H.H. and Winnik, M.A., “Polymer Interdiffusion vs. Crosslinking in Carboxylic Acid-Carbodiimide Latex Films,”Macromolecules, 32, 7692–7695 (1999).

    Article  ADS  CAS  Google Scholar 

  64. Aradian, A., Raphaël, E., and de Gennes, P.-G. “Strengthening of a Polymer Interface: Interdiffusion and Crosslinking,”Macromolecules, 33, 9444–9451 (2000).

    Article  ADS  CAS  Google Scholar 

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Department of Chemistry, Toronto, Ont., M5S 3H6, Canada.

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Winnik, M.A. Interdiffusion and crosslinking in thermoset latex films. Journal of Coatings Technology 74, 49–63 (2002). https://doi.org/10.1007/BF02720150

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