Activation spectrum of polystyrene

Figure 1 shows the activation spectrum of polystyrene measured by Hirt and co-workers (8). It represents the yellowing, as measured by the increase in absorbance at 4000 A., caused by the various wavelengths of ultraviolet radiation between 2800 and 4000 A. The ultraviolet source used for these measurements was a xenon arc equipped with a borosilicate... 

Figure I. Activation spectrum of polystyrene measured by Hirt et al. (8)...

The authors thank N. Z. Searle for the activation spectrum of polystyrene and M. Maiullo for carrying out part of the experimental work. 

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