Dyeing process and mechanism of eucalyptus veneer with Dalbergia bariensis heartwood pigment as dye

ObjectiveIn order to make full use of the processing residues of Dalbergia bariensis and improve the added value of eucalyptu, natural dye has been extracted from the Dalbergia bariensis heartwood.

MethodThe main components of Dalbergia bariensis heartwood content were analyzed by ultra-high performance liquid chromatography with quadrupole-electrostatic field orbitrap high resolution mass spectrometry. The best dyeing process and color fastness were measured. The binding mechanism of Dalbergia bariensis dye and eucalyptus veneer was analyzed by Fourier transform infrared spectroscopy (FTIR).The distribution characteristics of the dye in eucalyptus veneer were observed by the field emission scanning electron microscope (FESEM).

ResultNine phenols were identified from the pigment of Dalbergia bariensis heartwood by UPLC-Q-EXACTIVE-MS: malvidin, rhamnetin, butein, sakuranetin, alizarin, luteolin, hemotoxylin, pinocembrin, taxifolin. The optimal dyeing process of eucalyptus veneer was: dyeing temperature 90 ℃, dyeing time 12 hours, pigment mass fraction 4%, NaCl mass fraction 2%. The order of influencing factors of dyeing test was: temperature > pigment mass fraction > dyeing time > NaCl mass fraction. The order of influencing factors of color fastness was: temperature > pigment mass fraction > dyeing time > NaCl mass fraction. It was preliminarily determined as physical adsorption and intermolecular hydrogen bonding through the analysis of FTIR’s and FESEM’s reaction to the dyeing mechanism.

ConclusionNatural dye extracted from Dalbergia bariensis heartwood is used to imitate the precious rosewood by dyeing eucalyptus veneer, which blazes a trail in the full utilization of precious rosewood and explores the high value-added utilization of fast-growing wood.