INVESTIGATION OF ECO-FRIENDLY DYEING TECHNIQUE FOR VIETNAMESE BAMBOO STRIPS USING A NATURAL COLORANT EXTRACTED FROM ANNATTO SEEDS

Abstract

In this paper, dyeing of Vietnamese bamboo strips using a natural colorant derived from Vietnam annatto seeds have been studied. The annatto colorant extracted using boiling water in various pH was dyed on bamboo strips by exhaustion. The effects of various dyeing factors including temperature, pH and various mordant species on the chromatic behaviour of bamboo strips were investigated and optimized. The optimal dyeing conditions were high temperature (85-90 °C), alkaline medium (pH = 9-10), liquor ratio 1:20 and dyeing time 60 min. Fourier transform infrared spectroscopy (FTIR) was also conducted to get insight into the bonding mechanism between the extracted colorant and bamboo material. The chromatic behaviour of dyed bamboo strips was changed using different mordants such as aluminum potassium sulfate, copper sulphate, potassium dichromate and ferrous sulfate via post-treatment method.