Chemical Properties of Cotton Fiber

Chemical properties of cotton fiber:
1. Effect of acid: Cotton is attack by hot dilute acids or cold concentrated acids in which it disintegrates. It is not affected by cold weak acids.
2. Effect of alkali: To alkali there is an excellent resistance for Cotton. Cotton swells on caustic alkali's but it never damaged.
3. Effect of solvent: There are very few solvent that will dissolve cotton completely. It has a high resistance to normal solvents but is dispersed by the copper complexes cuprammonium hydroxide and cupriethelene diamine and by concentrated H2SO4 (70%).
4. Action of microorganism: Cotton fibers can resist moths and most insects but it can be attacked by fungi and bacteria.
5. Action of water: Water, which is very strong polar in nature, easily attacked by the polar –OH group of the cotton fiber. So that water is able to penetrate into the cellulose network of the cotton fiber. This water absorption causes swelling of the fiber.
6. Effect of temperature: Cotton fiber shows an excellent resistance to thermal decomposition. Prolonged heating at 100ºC shows the cotton no visible change heat at 120ºC for several hours shows the cotton little or no change in strength. But begin to turn yellow gradually. Cotton decomposes markedly at 150ºC.