Relationship between Dyeing Condition and Dyeability in Hair Colouring by Using Catechinone Prepared Enzymatically or Chemically from (+)-Catechin

Hair colouring was carried out by using catechinone prepared from (+)-catechin by enzymatic or chemical oxidation reaction. The difference of dyeability between the catechinone produced by enzymatic reaction (EC) and that produced by chemical reaction (CC) was studied changing the dyeing condition such as dye concentration, dyeing temperature, pH or the sort and concentration of salts. The colour of the hair dyed by EC or CC at 30°C is yellowish or reddish brown, respectively. The colour of the hair dyed by EC and CC is deeper at a higher dye concentration and at a higher temperature. Hair is dyed deepest by EC or CC at the solution pH = 6.04 or 5.45, respectively. The dyeability is increased by adding NaCl (≤4 M) or CaCl2 (≤1 M), while it is decreased by adding AlCl3. The colour fastness of the dyed hair to washing or ultraviolet light is high enough for practical use. Furthermore, it was found that colourants are obtained from tea extracts which contain catechin derivatives. Hair is dyed reddish brown by the colourants.

SURFACE MODIFICATION OF POLYPROPYLENE MICROFIBRE BY PLASMA-INDUCED VAPOR GRAFTING WITH ACRYLIC ACID

The hydrophilicity, dyeing and antistatic ability of polypropylene microfibre (PPMF) were improved by plasma-induced vapor grafting with acrylic acid. The effects of plasma discharge time, power, liquid phase acrylic acid temperature and environmental temperature on grafting yield were investigated. The existence of grafted polyacrylic acid (PAA) was verified by ESCA and ATR FT-IR. The morphology of grafted PAA was directly observed by SEM. The wicking test shows that the hydrophilicity of modified PPMF is greatly enhanced. The dyeability test of modified PPMF was carried out using Dispersion Yellow. It was found that the dye uptake ratio is linear to the weight percent of grafting. The antistatic ability was indicated by specific resistance. The specific resistance of modified PPMF was reduced to 10(6) similar to 10(7) Ohm . cm, thus the antistatic ability was considerably improved.

The effect of atmospheric pressure glow discharge plasma treatment on the dyeing properties of silk fabric

In this study,the effects of plasma treatment parameters on surface morphology,chemical constituent,dycabiliiy and color fastness of silk fabric were investigated.Atmospheric pressure glow discharge plasma generated with different applied voltages(0 kV to 45 kV)was used to treat the surface of silk fabrics.C I Natural Yellow 3 was used to dye untreated and plasma-treated silk fabrics.The physical analysis based on scanning electron microscopy showed that the surface of silk fabrics was affected by plasma treatment.The chemical analysis was investigated with x-ray photi>elcctron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy.The results showed that the content of C Is decreased with the increasing applied voltage,the content of N Is and O Is increased with the increasing applied voltage.The increasing K/S values represented that the dyeability of silk fabrics was improved after plasma treatment.The color fastness to dry and wet rubbing was decreased after plasma treatment.

Cationic Modification of Cellulosic Fibres with Polyepichloro-hydrinamine Resins to Offer a Potential Dyeing Process Producing Cleaner Dyeing Effluent

Cationic modifying agent ( PECH- amine) with lower molecular weight and containing less nitrogen was prepared and characterized. The water-soluble cationic modification agent has high reactivity for cotton. Cotton modified by this agent can be dyed under salt-free and neutral conditions with direct and reactive dyes. Dyes in the dyebath could be completely exhausted and a dyeing effluent without residual dyes and salt could be expected.

Synthesis and Characterization of Easily Colored Meta-aramid Copolymer Containing Ether Bonds

This work described the preparation of easily colored meta-aramid(PMIA) copolymers from m-phenylenediamine(MPD),isophthaloyl dichloride(IPC), and 3,4′-oxydianiline(3,4′-ODA) via solution polycondensation in N,N-dimethylacetamide(DMAc). The novel co-PMIAs were obtained in relatively high inherent viscosities ranging from 1.32 dL/g to 2.53 dL/g, which could be easily cast into flexible films with high transparence or spun into fibers. All the newly synthesized copolymers possessed excellent thermal stabilities even better than that of commercial PMIA, with 5% weight loss temperatures higher than 430 °C in nitrogen measured by TGA and glass transition temperature of 267–277 °C measured by DSC. The cast films exhibited good mechanical properties with a tensile strength up to107 MPa and a tensile modulus up to 2.2 GPa. The resultant PMIAs also showed good solubility and better dye ability for cationic dyes.