Dyeing of Oxyanthraquinones on Silk

Abstract

To elucidate the dyeing behavior of colouring matters in a madder, the dyeing properties of four oxyanthraquinones (1-hydroxyanthraquinone (HAQ), Quinizarin (QZ), Alizarin (AZ) and Prupurin (PR)) on silk were examined.
The dyeing isotherms of HAQ and QZ on non-mordanted silk was linear, namely of the partition type and those of AZ and PR were of the Freundlich type. The dyeing process of QZ on silk was exothermic, that is, the dye uptake decreased with a rise in temperature. The dyeing heat and standard affinity of QZ were comparable to those of some disperse dyes which had lower affinity on silk.
The dyeing isotherms of AZ and PZ on silk mordanted with Al³⁺ were of the H type. The dye uptake was large in even low dye concentration.