Nylon Fiber: Properties, Advantages and Disadvantages

The term nylon fiber refers to a group of linear polyamides. There are two approaches to creating nylon for making fibers. In the first method, molecules with an acidic group (COOH) at each end react with molecules that have amino (NH2) groups at each end. The resulting type of nylon is named based on the number of carbon atoms between the two acidic groups and two amines. For example, nylon 6,6, made from adipic acid and hexamethylenediamine, is frequently used in fiber production. Nylon molecules are fairly flexible, with weak forces like hydrogen bonds between the polymer chains. To create strong fibers, the polymer must be heated and drawn out. The combination of two compounds in an exact 1:1 ratio of acid to base is known as “nylon salt.” This salt is then dried and heated under a vacuum to remove water and create the polymer. In the second method, a compound with an amine at one end and an acid at the other end is polymerized to produce a chain with repeating units of −NH−[CH2]n−CO−)x. If n equals 5, it’s called nylon 6, another common form of this polymer. Commercial production of nylon 6 starts with caprolactam, using an open-ring polymerization process. In both methods, the polyamide is melted and then drawn out after cooling to achieve the desired properties for the intended use. In the 1930s, a research team led by American chemist Wallace H. Carothers, working for E.I. du Pont de Nemours & Company, developed nylons. The successful production of fiber through chemical synthesis using compounds readily available from air, water, coal, or petroleum prompted further research into polymers, leading to the rapid expansion of synthetic materials.