A simple controlled-temperature irradiator is described, which permits fabric samples to be irradiated at air temperatures in the range 35°C to 85°C. Photodegradation of wool fabrics, as assessed by measurement of breaking loads, tear strengths, and yel lowness indexes, increases rapidly as the temperature of irradiation is raised, and occurs 3 to 4 times faster at 75°C than at 35°C. A procedure is described for assessing the level of photoprotection conferred on wool by treatment with a UV absorber of the 2-hydroxybenzophenone type. Consistent lifetime improvement factors are ob tained for most levels of photodegradation, and for exposure either to the artificial light source or to sunlight through window glass.
References
1.
Evans, N. A., Leaver, I. H., Rosevear, J., Waters, P. J., and Wilshire, J. F. K., Use of Substituted 2-(2'-Hydroxyaryl)-2H-Benzotriazole-Sulfonates as Photoprotective Agents, Australian patent application PF 7151/ 82, 1982.
2.
Fincher, K.W. , Leeder, J.D., Sinclair , J.F., and White, M.A., An Economical Method for Accelerated Sunlight-Exposure Testing, J. Textile Inst.66, 268-270 (1975).
3.
Leaver, I.H. , Waters, P.J., and Evans, N.A., Dual Role of a Hydroxyphenylbenzotriazole UV-Absorber in the Photooxidation of Wool, J. Polym. Sci. Polym. Chem. Ed.17, 1531-1541 (1979 ).
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5.
Milligan, B. , and Holt, L.A., Ultraviolet Absorbers for Retarding Wool Photodegradation and Dye Fading: Sulfonated 2-Hydroxybenzophenone; and 2,2'-Dihydroxybenzophenones , Polym. Degr. Stab. (accepted for publication).
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Waters, P.J., Evans, N.A., Holt, L.A., and Milligan, B., The Use of Ultraviolet Absorbers for Reducing the Chemical and Physical Damage Caused by Prolonged Exposure of Wool to Light, in " Proc. 6th Int. Wool Text. Res. Conf, Pretoria ," V, 1980, pp. 195-204.
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