The Chemistry Of Synthetic Dyes. | Reactive Dyes

The "business end" that reacts with the fibre (e.g., vinyl sulfone or cyanuric chloride).

Links the chromophore to the reactive system. ⚗️ The Reaction Mechanism

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 The Chemistry of Synthetic Dyes. Reactive Dyes

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.

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 The "business end" that reacts with the fibre (e

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:

Known for incredibly vivid and brilliant shades. The chlorine atom on the dye molecule is

The dye attaches to the fibre through a chemical reaction triggered by alkaline conditions (high pH). There are two main types of reaction mechanisms: 1. Nucleophilic Substitution