science

Nylon 66

Nylon 66 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nylon 66 rather than just read about it. In short: Nylon 66 (loosely written nylon 6-6, nylon 6/6, nylon 6,6, or nylon 6:6) is a type of polyamide or nylon. It, and nylon 6, are the two most common for textile and plastic industries.

Key takeaways

Nylon 66 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nylon 66 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nylon 66 from memory before moving on to harder problems.

Reference excerpt

Nylon 66 (loosely written nylon 6-6, nylon 6/6, nylon 6,6, or nylon 6:6) is a type of polyamide or nylon. It, and nylon 6, are the two most common for textile and plastic industries. Nylon 66 is made of two monomers each containing six carbon atoms, hexamethylenediamine and adipic acid, which give nylon 66 its name. Aside from its superior physical characteristics, nylon 66 is attractive because its precursors are inexpensive.

Synthesis and manufacturing

Nylon 66 is synthesized by polycondensation of hexamethylenediamine and adipic acid. Equivalent amounts of hexamethylenediamine and adipic acid are combined in water. In the original implementation, the resulting ammonium/carboxylate salt was isolated and then heated either in batches or continuously to induce polycondensation.

n(HOOC−(CH2)4−COOH) + n(H2N−(CH2)6−NH2) → [−OC−(CH2)4−CO−NH−(CH2)6−NH−]n + (2n-1) H2O Removing water drives the reaction toward polymerization through the formation of amide bonds from the acid and amine functions. Alternatively, the polymerization is conducted on a concentrated aqueous mixture formed of hexamethylenediamine and adipic acid. It can either be extruded and granulated at this point or directly spun into fibers by extrusion through a spinneret (a small metal plate with fine holes) and cooling to form filaments.

Applications In 2011 worldwide production was two million tons. At that time, fibers consumed just over half of production and engineering resins the rest. It is not used in film applications as it cannot be biaxially oriented. Fiber markets represented 55% of the 2010 demand with engineering thermoplastics being the remainder. Nylon 66 is frequently used when high mechanical strength, rigidity, good stability under heat and/or chemical resistance are required. It is used in fibers for textiles and carpets and molded parts. For textiles, fibers are sold under various brands, for example Nilit brands or the Cordura brand for luggage, but it is also used in airbags, apparel, and for carpet fibres under the Ultron brand. Nylon 66 lends itself well to make 3D structural objects, mostly by injection molding. It has broad use in automotive applications; these include "under the hood" parts such as radiator end tanks, rocker covers, air intake manifolds, and oil pans, as well as numerous other structural parts such as hinges, and ball bearing cages. Other applications include electro-insulating elements, pipes, profiles, various machine parts, zip ties, conveyor belts, hoses, polymer-framed weapons, and the outer layer of turnout blankets. Nylon 66 is also a popular guitar nut material. Nylon 66, especially glass fiber reinforced grades, can be effectively fire retardant with halogen-free products. Phosphorus-based flame retardant systems are used in these fire-safe polymers and are based on aluminium diethyl phosphinate and synergists. They are designed to meet UL 94 flammability tests as well as Glow Wire Ignition Tests (GWIT), Glow Wire Flammability Test (GWFI) and Comparative Tracking Index (CTI). Its main applications are in the electrical and electronics (E&E) industry.

Illustrations

Worked examples

Example 1 — a first encounter with Nylon 66

Start with the simplest possible case. Write down what Nylon 66 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nylon 66 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nylon 66 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nylon 66

In research: Nylon 66 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nylon 66 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nylon 66 is common in secondary-school and first-year university syllabi. It links to neighbouring topics American inventions, DuPont products, Plastics, so understanding it makes those chapters shorter.
In everyday life: Look for Nylon 66 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Nylon 66 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nylon 66 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nylon 66 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nylon 66 in simple terms?

Nylon 66 (loosely written nylon 6-6, nylon 6/6, nylon 6,6, or nylon 6:6) is a type of polyamide or nylon. It, and nylon 6, are the two most common for textile and plastic industries.

Why does Nylon 66 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nylon 66?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nylon 66.