Reactive Orange 5 CAS 70210-21-8

What is Reactive Orange 5 CAS 70210-21-8?

Reactive Orange 5 CAS 70210-21-8 is a water-soluble azo dye featuring a sulfatoethylsulfone reactive group that undergoes nucleophilic substitution under alkaline conditions (pH 9–11) to form stable β-sulfatoethyl ether bonds with hydroxyl groups on cotton and viscose, ensuring high fixation efficiency and color fastness; it is synthesized via diazotization and coupling of aromatic amines followed by sulfation of the reactive moiety, but its use generates colored wastewater that requires treatment through adsorption or biodegradation to mitigate environmental impact.

Specification

Feature

• Physical Properties: Orange to brownish-orange powder with a molecular weight of 573.57 g/mol, high water solubility due to sulfonate groups, and absorption maximum around 490–500 nm; exhibits low volatility and decomposes above 250°C without a defined melting point.
• Chemical Reactivity: Contains a vinyl sulfone precursor (sulfatoethylsulfone) that activates under alkaline conditions for covalent bonding to cellulose; stable in neutral media but hydrolyzes to inactive vinyl sulfone if unfixed; incompatible with strong acids or oxidants that may degrade the azo chromophore.
• Synthesis: Involves diazotization of a substituted aniline (e.g., 4-(2-hydroxyethylsulfonyl)aniline), coupling with a naphthalenesulfonic acid derivative like H-acid or J-acid, followed by acetylation and sulfation to introduce the reactive group, yielding technical-grade products with 50–70% purity.
• Safety Profile: May cause skin, eye, or respiratory irritation upon exposure; low acute toxicity (LD50 >2000 mg/kg oral, rat) but potentially mutagenic or allergenic due to azo structure; harmful to aquatic life with long-term effects, necessitating PPE handling and effluent treatment.

Application

• Textile Dyeing: Used in exhaust, cold-pad-batch, and continuous dyeing of cotton, rayon, and linen for vibrant orange hues in apparel, towels, and upholstery with good to excellent wash and light fastness.
• Printing: Incorporated into reactive printing pastes for precise orange patterns on cellulosic fabrics, offering high color yield and resistance to bleeding.
• Paper and Ink Coloration: Applied for surface dyeing of paper and in water-based inks where stable, bright orange pigmentation is needed.
• Research and Wastewater Studies: Serves as a model azo dye in investigations of photocatalytic degradation, biosorption, and advanced oxidation processes for dye effluent remediation.

Packaging

Mikem offers flexible packaging options, including 25 kg of fiber drums for liquid products and 15–25 kg PP/PE bags for powder products, all customizable to meet your specific needs.