Known for incredibly vivid and brilliant shades.
While reactive dyes are safer than many older synthetics (like those using heavy metals), they require large amounts of salt and water for the fixation and rinsing processes. Modern research focuses on "low-salt" dyes and increasing the to reduce chemical waste.
The part that provides color (usually azo, anthraquinone, or phthalocyanine groups). Solubilising Group: Often sulfonic acid salts ( SO3Nacap S cap O sub 3 cap N a ) that make the dye water-soluble. The Chemistry of Synthetic Dyes. Reactive Dyes
Typical of dyes (like Remazol). In an alkaline bath, the dye undergoes an elimination reaction to form a vinyl sulfone group, which then adds across the fiber's functional groups. Result: A highly durable covalent linkage. ⚡ Key Properties
Common in dyes. The chlorine atom on the dye molecule is displaced by the hydroxyl ( OHcap O cap H ) group of the cellulose or the amino ( NH2cap N cap H sub 2 ) group of protein fibres. Result: A stable carbon-oxygen or carbon-nitrogen bond. 2. Nucleophilic Addition Known for incredibly vivid and brilliant shades
The "business end" that reacts with the fibre (e.g., vinyl sulfone or cyanuric chloride).
Generally requires salt to drive the dye into the fibre and alkali to fix it. 🌍 Environmental Impact The part that provides color (usually azo, anthraquinone,
The chemistry of reactive dyes centers on their unique ability to form a permanent covalent bond with the substrate, typically cellulose (cotton) or protein fibres (wool/silk). Unlike other dyes that simply "sit" on or inside the fibre, reactive dyes become a chemical part of the fibre itself. 🧪 Chemical Structure Reactive dyes consist of four primary components: