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Reduced indentation recovery temperature at the surface of a crosslinked epoxy coating in humid conditions

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Abstract

Relaxation of surface defects shows that the surface of a crosslinked epoxy system, under normal laboratory conditions, apparently has a softening transition temperature that is approximately 20°C lower than calorimetric measures of T g in the bulk. Physical aging data here confirms that this transition does resemble a glass transition. This observation is significant for properties that are determined by the surface of a coating. When ambient humidity is such that an epoxy may absorb significant quantities of moisture, it is plasticized, reducing its T g. When the relaxation of nanoindentations was measured in a humid environment, the value of this softening surface transition temperature was further reduced by 10°C. Thus, the surface properties of a polymer coating, such as wear, durability, friction, will depend not only on the ambient temperature, but also on whether the environment is humid. This is very important when such a coating responds to an environment that changes, e.g., natural weather.

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References

  1. Jones, RAL, Richards, RW, Polymers at Surfaces and Interfaces. Cambridge University Press, UK (1999)

    Google Scholar 

  2. Torkelson, JM, The Distributions of T g Values and Physical Aging Across Thin and Ultrathin Polymer Films and Within Polymer Nanocomposites, American Physical Society, March 2005

  3. Shi, X, Croll, SG, “Thermal-Induced Recovery of Small Deformations and Degradation Defects on Epoxy Coating Surface.” J. Coat. Technol. Res., 7 (1) 73–84 (2010)

    Article  CAS  Google Scholar 

  4. Kiil, S, “Quantification of Simultaneous Solvent Evaporation and Chemical Curing in Thermoset Coatings.” J. Coat. Technol. Res., 7 (5) 569–586 (2010)

    Article  CAS  Google Scholar 

  5. Xian, G, Karbhari, VM, “Segmental Relaxation of Water-Aged Ambient Cured Epoxy.” Polym. Deg. Stab., 92 1650–1659 (2007)

    Article  CAS  Google Scholar 

  6. Ranjbar, Z, Rastegar, S, “Evaluation of Mar/Scratch Resistance of a Two Component Automotive Clear Coat Via Nano-Indenter.” Prog. Org. Coat., 64 4387–4391 (2009)

    Article  Google Scholar 

  7. Jones, RAL, “The Dynamics of Thin Polymer Films.” Curr. Opin. Colloid Interface Sci., 4 (2) 153–158 (1999)

    Article  Google Scholar 

  8. Kerle, T, Lin, Z, Kim, HC, Russell, TP, “Mobility of Polymers at the Air/Polymer Interface.” Macromolecules, 34 3484–3492 (2001)

    Article  CAS  Google Scholar 

  9. Zaitseva, AV, Zaitsev, VB, Rudoy, VM, “The Study of Polystyrene Surface Glass Transition by Luminescent Molecular Probes.” Surf. Sci., 566–568 821–825 (2004)

    Article  Google Scholar 

  10. Fakhraai, Z, Forrest, JA, “Measuring the Surface Dynamics of Glassy Polymers.” Science, 319 600–604 (2008)

    Article  CAS  Google Scholar 

  11. Bliznyuk, VN, Assender, HE, Briggs, GAD, “Surface Glass Transition Temperature of Amorphous Polymers. A New Insight with SFM.” Macromolecules, 35 6613–6622 (2002)

    Article  CAS  Google Scholar 

  12. Shi, X, Fernando, BMD, Croll, SG, “Concurrent Physical Aging and Degradation of Crosslinked Coating Systems in Accelerated Weathering.” J. Coat. Technol. Res., 5 (3) 299–310 (2008)

    Article  CAS  Google Scholar 

  13. Cao-Paz, A, Covelo, A, Fariña, J, Nóvoa, XR, Pérez, C, Rodríguez-Pardo, L, “Ingress of Water into Organic Coatings: Real-Time Monitoring of the Capacitance and Increase in Mass.” Prog. Org. Coat., 69 150–157 (2010)

    Article  CAS  Google Scholar 

  14. Shi, X, Hinderliter, BR, Croll, SG, “Environmental and Time Dependence of Moisture Transportation in an Epoxy Coating and Its Significance for Accelerated Weathering.” J. Coat. Technol. Res., 7 (4) 419–430 (2010)

    Article  CAS  Google Scholar 

Download references

Acknowledgments

This work was funded by the Army Research Laboratory and NSF EPSCoR, North Dakota.

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Authors and Affiliations

  1. Department of Coatings and Polymeric Materials, North Dakota State University, Fargo, ND, 58102, USA

    Xiaodong Shi & Stuart G. Croll

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  1. Xiaodong Shi
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  2. Stuart G. Croll
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Correspondence to Stuart G. Croll.

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Shi, X., Croll, S.G. Reduced indentation recovery temperature at the surface of a crosslinked epoxy coating in humid conditions. J Coat Technol Res 8, 535–539 (2011). https://doi.org/10.1007/s11998-011-9335-0

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