Generally requires salt to drive the dye into the fibre and alkali to fix it. 🌍 Environmental Impact
The "business end" that reacts with the fibre (e.g., vinyl sulfone or cyanuric chloride).
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: The Chemistry of Synthetic Dyes. Reactive Dyes
A major challenge where the dye reacts with water instead of the fibre, creating "spent" dye that must be washed away.
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 Generally requires salt to drive the dye into
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.
Links the chromophore to the reactive system. ⚗️ The Reaction Mechanism Unlike other dyes that simply "sit" on or
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