Positron Studies of Polymeric Coatings.
Positron Studies of Polymeric Coatings.
(782 K)
Jean, Y. C.; Mallon, P. E.; Zhang, R.; Chen, H.; Li, Y.;
Zhang, J.; Wu, Y. C.; Sandreczki, T. C.; Suzuki, R.;
Ohdaira, T.; Gu, X.; Nguyen, T.
Radiation Physics and Chemistry, Vol. 68, No. 3/4,
395-402, October/November 2003.
Keywords:
coatings; weathering; degradation; polymers; slow
positrons
Abstract:
In complicated coating systems, positrons have shown
sensitivity in detecting the early stage of
deterioration due to weathering, specially, in probing a
specific location or depth of coatings from the surface
through interfaces and the bulk. Existing extensive
experimental positron data show that positron
annihilation signals respond quantitatively to the
deterioration process due to weathering. Now it is
possible to detect the very early stage of coating
deterioration at the atomic and molecular scale by using
positrons, typically in days as compared to years by
conventional methods. This paper summarizes recent
positron studies in polymeric coatings. Correlations
between positron data and a variety of chemical,
physical and engineering data from ESR, AFM, cross-link
density, gloss, and cyclic loading are presented.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899