REACTIVE DYE Meaning and
Definition
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A reactive dye is a type of coloring agent used in textile dyeing that forms a chemical bond with textile fibers. It is specifically developed to chemically react with the fiber molecules, creating a permanent and strong attachment. This characteristic allows the dye to become an integral part of the fabric instead of just coating its surface.
The reactive dye's chemical structure comprises a chromophore, which is responsible for its color, and a reactive group that can chemically connect with specific functional groups found in the textile fibers. The reactive group typically includes a chloride or sulfate group that reacts with hydroxyl or amino groups in the fiber, forming a covalent bond. This strong covalent bond ensures excellent colorfastness and resistance to washing and fading.
The dyeing of textiles with reactive dyes often requires specific conditions, such as alkaline pH, elevated temperatures, and the presence of electrolytes. These conditions aid the chemical reaction between the dye and the fibers, resulting in a vibrant and durable coloration.
Reactive dyes are widely used for the dyeing of natural and synthetic fibers, including cotton, rayon, silk, and polyester. They offer a broad spectrum of bright and intense colors, making them popular in the fashion and textile industries. Furthermore, they are known for their good lightfastness, ensuring the colors remain stable even when exposed to sunlight over time.
Etymology of REACTIVE DYE
The word "reactive dye" is derived from the combination of two components: "reactive" and "dye".
The term "dye" originates from the Old English word "deah", which means "to dye or color". It has its roots in the Proto-Germanic word "daubjanan", meaning "to smear". Over time, this term evolved to specifically refer to substances used to color fabrics and other materials.
The word "reactive" in the context of reactive dye refers to the characteristic of these dyes to chemically react with the fiber they are being applied to. Reactive dyes form covalent bonds with the fibers of the fabric, resulting in excellent colorfastness and wash-fastness. This reactivity distinguishes them from other types of dyes. Hence, the term "reactive dye" is used to describe this specific group of dyes based on their reactive nature.
