Effect of Topical Applications of Antioxidants and Quenchers on the Photoyellowing of Fluorescently Whitened Wool Fabric

Abstract

Wool that has been optically whitened with fluorescent whitening agents is susceptible to photoyellowing at a much accelerated rate compared to unwhitened wool. This effect is especially noticeable when the wool is exposed in the presence of moisture (the "wet" state). Topical applications of several antioxidants and singlet oxygen quenchers applied to fluorescently whitened wool fabric have been evaluated with regard to their effect on "wet" and "dry" exposures to ultraviolet radiation. A com pound from the sulfide class of antioxidants was most effective for wet exposures. This effect was moisture related. A hindered phenol antioxidant had the greatest effect on dry exposures. A nickel chelate compound was equally effective for both wet and dry states. The decrease in the tryptophan content of wet exposed fabric was related to the degree of yellowing that developed in the fabric.