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Reciprocity Law Experiments in Polymeric Photodegradation: A Critical Review



Jonathan W. Martin, Joannie W. Chin, Tinh Nguyen


celerating the photodegradation of polymeric materials is of great interest in weathering research. One way of achieving acceleration is by exposing polymeric materials to a high radiant flux, but questions have arisen as to whether high radiant flux results can be extrapolated to in-service flux levels. Experiments designed to test this premise are called reciprocity law experiments. An extensive review has been conducted to access the state-of-the-art reciprocity law experiments in the photography, photoconductivity, photo-medicine, photobiology, and polymer photodegradation literatures. From this review, the Schwarzschild law (a power law generalization of the reciprocity law) appears to model adequately photoresponse versus radiant flux for all materials and systems. Moreover, a band theory model appears to explain the observed Schwarzschild law p-coefficient values in addition to other experimental phenomena. Obstacles to the general acceptance of high radiant flux, laboratory-based experiments are discussed.
Progress in Organic Coatings
No. 3-4


band theory, photoconductance, photodegradation, photography, polymers, reciprocity law, Schwarzschild Law


Martin, J. , Chin, J. and Nguyen, T. (2003), Reciprocity Law Experiments in Polymeric Photodegradation: A Critical Review, Progress in Organic Coatings, [online], (Accessed April 23, 2024)
Created September 1, 2003, Updated February 19, 2017