basic-dyes-1.pptx

BASIC DYE Textile Processing And Finishing Presented by ABDUL HASEEB SAEED ( TE-032 ) MUNTAZIR MEHDI (TE-036) MUHAMMAD ISMAIL UDDIN (TE-033) ❖ Basic dye Basic dyes are also known as cationic dyes , it acts as base when made soluble in water, they form a c...

BASIC DYE Textile Processing And Finishing Presented by ABDUL HASEEB SAEED ( TE-032 ) MUNTAZIR MEHDI (TE-036) MUHAMMAD ISMAIL UDDIN (TE-033) ❖ Basic dye Basic dyes are also known as cationic dyes , it acts as base when made soluble in water, they form a colored cationic salt which can react with the anionic sites on the surface of substrate. There are less hydrophilic groups in basic dyes so that they are insoluble in water. When we dissolve them, we use alcohol or acetic acid and then dilute with water. Basic dyes are sensitive to temperature, so that both temperature of the dissolution-dilution and dye-bath should not be too high. ❖ Chemical structure of basic dye: The chemical structure of basic dyes includes aromatic methane, triarylmethane, azo type and nitrogen-containing heterocyclic compounds (such as xanthene, oxazine and thiazine, etc.). Basic Violet Basic Blue 2 11 Here's a breakdown of the key terms to understand how color is generated in basic dyes:  Chromophore This is the part of the molecule that is responsible for absorbing visible light and giving the dye its color. Common chromophores in basic dyes include azo groups (–N=N–), conjugated imine groups (–C=N–), heterocyclic rings (like pyridinium and thiazolium rings), and triphenylmethane groups. Chemical structure of the triphenylmethane dyes Basic Fuchsin (BF), Crystal Violet (CV), Malachite Green (MG) and the boroxine derivative BO. R 1 and R 2 denote donor-substituent group  Auxochrome An auxochrome is a functional group in a dye molecule that influences properties like solubility, ionization, and the intensity or shade of the color. Common auxochromes in basic dyes include amino groups (-NH2), alkylamino groups (-NHR), and dialkylamino groups (-NR2). While auxochromes don't directly affect the color itself, they can influence the way the chromophore interacts with light, resulting in deepening or brightening of the color.  The auxochrome in Methyl Orange is the dimethylamino group (-N(CH3)2) attached to the benzene ring. This positively charged group makes the dye a cationic dye (basic dye). While it doesn't directly affect the base color (orange from the azo group), it can intensify the color and influence its solubility. ❖ Advantages of basic dye: 1. Moderate substantively 2. Relatively economical 3. High Tinctorial strength 4. Wide shade range 5. Shows good brightness 6. Includes some of the most brilliant synthetic dyes ❖ Applications of Basic Dye: ▪ Basic dyes are extensively used for dyeing of: ▪ Jute ▪ Silk ▪ Wool ▪ Coir ▪ Acrylic fibers ▪ Leathers ▪ Paper ▪ Dried flower  ❖ Limitations Of Basic Dye: □ Poor shade stability □ Poor lightfastness. □ High Acid Content □ Colored Backwaters □ Preferential dyeing ▪ This dye is toxic in nature, just like any other die. Therefore, it is extremely important to make sure that safety precautions are always followed, before buying and using these dyes. ❖ Modified Basic Dyes: Having same chemistry as basic dyes, modified basic dyes have a bit longer molecular structures in comparison to typical conventional basic dyes. Though still cationic in nature, modified basic dyes exhibit improved fiber coverage and substantivity on many furnishes, making them ideal for dyeing applications. Some of the key advantages over conventional basic dyes include: ✔ Better Light fastness ✔ Clear backwaters ✔ Covers all fibers ✔ Excellent substantively THANKYOU