Nylon 66[3]

Updated: 2026-09-15

Overview

Nylon 66 (PA66) is a synthetic polyamide first developed by DuPont in the 1930s. It is produced through the polycondensation of adipic acid and hexamethylenediamine, resulting in a polymer with alternating six-carbon units. This structure gives Nylon 66 its characteristic strength and durability, making it one of the most widely used engineering plastics. Compared to other nylons like Nylon 6, PA66 offers higher melting points and better mechanical properties, though it is more sensitive to moisture absorption. Its versatility has led to adoption across industries from automotive to consumer goods, where its balance of performance and processability is valued.

Physical and Chemical Properties

Nylon 66 exhibits a crystalline structure that contributes to its high tensile strength (up to 80 MPa) and stiffness. It maintains dimensional stability up to 180°C, with short-term tolerance to higher temperatures. The material absorbs up to 2.5% moisture at equilibrium, which can affect mechanical properties and requires pre-drying before processing. Chemically, PA66 resists oils, fuels, and many solvents but is attacked by strong acids and oxidizers. Its abrasion resistance exceeds most plastics, with a low coefficient of friction in bearing applications. UV stabilizers are often added for outdoor use, as untreated nylon degrades under prolonged sunlight exposure.

Main Applications

In automotive engineering, PA66 is used for radiator end tanks, intake manifolds, and cable ties due to its heat resistance. Electrical applications include circuit board components and connector housings, leveraging its dielectric properties. Industrial uses encompass gears, bushings, and conveyor belts where wear resistance is critical. The textile industry employs Nylon 66 fibers for carpets, ropes, and high-performance apparel like firefighter gear. Consumer goods range from power tool housings to kitchen utensils. Glass or mineral-filled grades enhance stiffness for structural parts, while impact-modified variants suit snap-fit components.

Safety and Storage

PA66 pellets pose minimal hazard at room temperature but generate hazardous fumes if overheated during processing (>300°C). Adequate ventilation is required to prevent inhalation of decomposition products containing carbon monoxide and nitrogen oxides. Dust control measures should be implemented during handling to avoid respiratory irritation. Storage recommendations include sealed moisture-proof packaging with desiccants, as absorbed water can cause hydrolysis during high-temperature processing. Bulk containers should be kept at <50% relative humidity and below 40°C to prevent property degradation over extended periods.

B2B Procurement Guide

When sourcing Nylon 66, specify required certifications such as ISO 9001, UL listings, or automotive standards like IATF 16949 for critical applications. Key parameters to verify include melt flow index (MFI), tensile modulus, and impact strength values relevant to your use case. Consider regional supply chains: major producers operate in North America, Europe, and Asia, with price variations based on raw material (adipic acid) costs. For large-volume purchases, negotiate contracts with price adjustment clauses linked to feedstock markets. Always request material data sheets (MDS) and batch test reports for quality assurance.