The Chemistry Of Synthetic Dyes. Reactive Dyes Guide

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 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 Chemistry of Synthetic Dyes. Reactive Dyes

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. Typical of dyes (like Remazol)

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

Excellent, because the dye is chemically locked to the fibre. ⚡ Key Properties The chemistry of reactive dyes

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