Dyeing of silk yarn with the natural extract from the underutilized tropical fruit pericarp of Ptychosperma macarthurii

Abstract

Flavonoid constituents from the aqueous extract of the fruit pericarp of P. macarthurii have potential use as dyestuffs for silk. In this work, silk yarn which was pretreated with a microcrystalline chitosan as well as a polydopamine, followed by dyeing with the P. macarthurii extract provided better depth of shade (K/S) and also gave better fastness to light and washing than the untreated dyed silk yarn. In addition, it was found that simultaneous mordanting with copper sulfate exhibited better fastness to light compared with the other samples. Post-mordanting silk yarn with a bio-mordant solution from Memecylon scutellatum leaves or alum gave good light and wash fastness of the resultant dyed yarn compared with the untreated dyed silk yarn. Moreover, the dyed silk yarn with this extract showed antifungal activity against Aspergillus niger, Penicillium chrysogenum and Candida albicans.