Application of benzotriazole reactive UV absorbers to cellulose and determining sun protection of treated fabric spectrophotometrically

Abstract

UV absorbers for treating cotton textiles with the aim of increased protection against harmful effects of UV component of solar radiation have been prepared by reactions of five different aminophenylsulfobenzotriazoles with the condensation product of 4-aminophenyl-sulfatoethylsulfone and cyanuric chloride. The UV absorbers with two different reactive groups (monochlorotriazine and aromatic vinylsulfone), capable of formation of covalent bonds with hydroxyl groups of cellulose, were applied to one cellophane foil and two cotton fabrics of different porosities. This treatment increased the ultraviolet protection factor from a value of UPF 5 3 to UPF 5 100 and above. For attaining a high UPF value, the cotton material should exhibit low porosity. The UV absorbers with 2-hydroxyphenyl group are stable in light and do not fluoresce on the fabric on contrary to derivatives without 2-hydroxyphenyl group or with 2-methoxyphenyl group. The high photostability of absorbers is explained by the possibility to disperse the absorbed energy of UV radiation in the form of harmless energy such as IR radiation (heat) through the reversible hydrogen bond between phenolic hydroxyl group and triazine cycle. The UV filters block the effect of optical brightening agents on cotton by quenching the fluorescence.

Effect of reactive dyeing on theUVprotection affected by knitted fabric made from different types of cotton fibre

“…The extent of improvement in UPF values is dependent upon how much more dyestuff is available in the fabric. Moreover, the reactive dye interacts vigorously with the hydroxyl groups on the cellulose chains which form covalent bonds with the cellulose fibre . The excellent dye affinity and uptake imply that the dye is sufficient to absorb ultraviolet radiation in the visible and UV radiation band .…”

Quartz plates for determining sun protection in vitro and testing photostability of commercial sunscreens

“…The spectrophotometer extension is designed for measuring the SPF of textiles and sun glasses [7,8]. The spectrophotometer has a horizontal table on which the plate with sunscreen is placed.…”

Multi-functional properties of cotton fabrics treated with UV absorber and N-halamine

“…The anti-UV finishing of cotton fabric is necessary due to its inferior anti-UV property. Organic UV absorbers and inorganic UV shielding agents are widely used as UV protecting agents of cotton fabrics, and the UPF value could be improved obviously [10][11][12][13][14][15]. The chemical bond formed between UV protecting agent and cotton fabrics could enhance the fastness of UV protecting agent.…”