Tihana Dekanić

Impact of Artificial UV-Light on Optical and Protective Effects of Cotton After Washing with Detergent Containing Fluorescent Compounds

Abstract Bleached cotton and polyester/cotton blend fabrics were laundered at 60°C and 90°C with standard ECE detergent with addition of selected fluorescent compounds through 10 cycles. As fluorescent whitening agents for cellulosic materials are most often used in detergents, two types of these were selected – stilbene and biphenyl. UV absorber, a stilbene derivative, as a separate type of fluorescent compounds, was added on its own and in a combination with both types of fluorescent whitening agents. After each laundering cycle cotton and PES/cotton blend fabrics were exposed to artificial light for 60 and 180 minutes. Obtained optical and protective effects were monitored through whiteness degree, remission and Ultraviolet Protection Factor (UPF). Optical effects of cotton fabrics laundered in a detergent containing fluorescent whitening agents of stilbene and biphenyl type exhibit considerable sensitivity to light. It was not found that irradiation reduces the UPF meaning that even decomposition products of fluorescent compounds, created by irradiation, absorb UV radiation as well.