Nylon 6,6 ((C₁₂H₂₂N₂O₂)n) — Properties, Uses & Safety

Overview

Nylon 6,6 is one of the most important synthetic polymers ever created, with the repeating unit formula (C12H22N2O2)n and a monomer molar mass of 226.32 g/mol. Developed by Wallace Carothers at DuPont in 1935, it was the first commercially successful synthetic fiber and revolutionized the textile industry. Nylon 6,6 is a polyamide, meaning its polymer chain is held together by amide bonds formed through a condensation reaction between hexamethylenediamine and adipic acid. This condensation polymerization releases water as a byproduct, making it a classic example studied in polymer chemistry courses. At standard conditions, Nylon 6,6 is a white to off-white opaque solid with excellent mechanical strength, abrasion resistance, and a relatively high melting point of about 264 degrees C — properties that arise from extensive hydrogen bonding between the amide groups of adjacent polymer chains. In everyday life, Nylon 6,6 is found in textiles and stockings, toothbrush bristles, carpet fibers, ropes, guitar strings, and engineering components like gears and bearings. Its combination of toughness, low friction, and chemical resistance makes it ideal for mechanical parts that must withstand repeated stress. Nylon 6,6 has no significant GHS hazard classifications in its solid polymer form, though the monomers used in its production require careful handling. For chemistry students, Nylon 6,6 is an outstanding example of condensation polymerization, intermolecular hydrogen bonding in polymers, and the relationship between molecular structure and macroscopic material properties. The famous nylon rope trick demonstration — where a continuous nylon fiber is pulled from the interface of two immiscible solutions — vividly illustrates interfacial polymerization and remains one of the most memorable experiments in introductory chemistry.

IUPAC Name

poly[imino(1,6-dioxohexamethylene)iminohexamethylene]

CAS Number

32131-17-2

PubChem CID

0

Molecular Formula

(C₁₂H₂₂N₂O₂)n

Molar Mass

226.316 g/mol

State at STP

solid

Appearance

White to off-white opaque solid