Abstract

• Tamarind (Tamarindus indica L.) is abundantly found in Myanmar and is also a commercially used plant. In natural dyeing tannins play an important role as a mordant and have an affinity to cellulose as well as to protein fiber. This study is aimed to the extraction of natural tannin from tamarind seed testa and application of cotton and silk fabric as natural mordant. The color compounds present in tamarind seed testa were identified by phytochemical tests. The mineral content of tamarind seed testa was analyzed by Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopy. Tannin was extracted from tamarind seed testa using ethanol-water mixture by simple distillation method. The effects of extraction temperature, time and ethanol-water ratio on the yield percent of tannin powder were investigated. In the extraction with 95 % ethanol-water mixture, ethanol-water ratio (35:15), extraction time 60 min and temperature 50 °C were suitable conditions for the preparation of extracted tannin. The functional groups present in extracted tannin was determined by using FTIR spectrometer. The extracted tannin powder was applied as a natural mordant alone and the tannin treated fabric was further mordanted with copper sulphate for dyeing of cotton and silk fabrics. The washing and rubbing fastness of dyed fabrics were tested by grey scale.