Ellagic acid from gallnut (Quercus infectoria): Extraction and determination of its dyeing conditions for natural fibres

The dyestuff of ellagic acid in gallnut (Quercus infectoria) was extracted and used in dyeing of woolen strips, feathered-leather and cotton using three types of mordanting methods at various pH values. Selected transition element salts [CuSO₄ 5H₂O, FeSO₄ 7H₂O, ZnSO₄ 7H₂O, Al(NO₃)₃. 9H₂O] were used as mordant agent at various pH. The dyed samples with highest fastness were obtained by Cu(II) for all samples except for cotton and by Al(III) for only cotton at pH 8 in the pre-mordanting method. It was also observed that gallnut plant based ellagic acid dyestuff would probably be an important raw material in dyeing process of natural textile fibers.