Nylon

Nylon is a special kind of material made by scientists, called a synthetic polymer. It has special links between its parts, called amide linkages, that help it stay strong and flexible. Nylon can come in different colors, often looking brownish, and feels soft, almost like silk.

Because nylon is a thermoplastic, it can be melted and shaped into many forms, like threads, thin sheets, and even solid pieces. People add different things to nylon to change how it looks and works even more.

There are many kinds of nylon. Some are named with numbers, like nylon-6,6, which comes from two different building blocks. Others, like nylon-6, come from a single building block. Nylon is used in lots of everyday things, such as clothes, car parts, electrical equipment, and even the plastic wrap used to keep food fresh.

History

Researchers at DuPont began developing new fibers, leading to the creation of rayon. This experience helped them invent nylon. The development of nylon took eleven years, starting in 1927 and ending in 1938, just before the 1939 New York World's Fair. The project started when Charles Stine suggested a new way to organize DuPont's chemical department. Wallace Hume Carothers, a Harvard instructor, led the polymer research group. He built on the work of German chemist Hermann Staudinger and made big advances in polymer science.

Nylon was the first successful synthetic thermoplastic polymer. DuPont started researching it in 1927. The first type, nylon 66, was made on February 28, 1935, by Wallace Hume Carothers. Another type, nylon 6, was developed by Paul Schlack in 1938.

In 1930, Carothers' team made two new polymers: neoprene, a synthetic rubber used in World War II, and another elastic paste that later became nylon. By 1935, they created "polymer 6-6," which became nylon. Julian W. Hill used a cold drawing method to make a polyester in 1930, and Carothers used this method in 1935 to fully develop nylon. The first nylon, nylon 6.6, was made on February 28, 1935. It had the right elasticity and strength but needed a complex manufacturing process. DuPont patented the polymer in 1938 and quickly became the only producer. Carothers died before nylon was announced. The name "Nylon" came from changing "norun" to a marketable name.

Nylon was first sold commercially in a nylon-bristled toothbrush in 1938 and became famous when women's stockings, called "nylons," were shown at the 1939 New York World's Fair and sold in 1940. They were very popular, with 64 million pairs sold in the first year. During World War II, almost all nylon was used for military parachutes and parachute cord. After the war, people eagerly waited for nylon to return. When it did, there were delays, leading to high demand and shortages. Women even made clothes from old nylon tents and parachutes.

DuPont worked with fashion designers to show the beauty of nylon fabrics. Blending nylon with other fibers like cotton, polyester, and spandex solved problems with pure nylon, such as discomfort and static electricity. These blends kept the good qualities of nylon while making clothes more comfortable and affordable.

The name "Nylon" was created through a process. It was originally meant to be "No-Run" but was changed to avoid claiming it was run-proof. The letters "nyl" were arbitrary, and "on" was chosen to match other fiber names like cotton and rayon.

Nylon became very popular in the 1940s and 1950s for its durability and thinness. It grew in popularity again in the 1970s for its flexibility and lower cost. Even with concerns about oil use and environmental impact, nylon remained important. Today, nylon is used in many things, including the flag planted on the moon.

Chemistry

The words "PA" and "Nylon" mean the same thing. Scientists use special names to describe different types of nylon. These names use numbers to show how many carbon atoms are in the building blocks that make the nylon.

For example, "Nylon 6" is made from one kind of building block, and "Nylon 6,10" is made from two different building blocks. The numbers tell us how many carbon atoms are in each building block.

Types

Nylon 66 and related heteropolymers

Nylon 66 and similar types are made from two different building blocks that fit together. These blocks have special ends that let them link up in a special way. This linking creates the nylon material. Wallace Carothers at DuPont was the first to make nylon 66. Getting the right amounts of these building blocks can be tricky, but scientists found a way to make a special solid that helps ensure the right mix.

Nylon 6 and related homopolymers

Nylon 6 is made from a single building block that folds into a ring shape. When heated, this ring opens up and links with others to form the nylon material. Paul Schlack discovered this method, and it creates nylon with a lower melting point than nylon 66.

Nylon 1,6

Nylon can also be made using different starting materials, such as special chemicals that help form the links in the material.

Copolymers

Mixing different building blocks when making nylon can change how the material behaves. This can lower how hot the nylon needs to be to change shape.

Blends

Many types of nylon can mix together, creating new materials with different properties.

Crystallinity

Nylon can be organized in different ways. Some types pack together tightly, while others are more mixed and less organized. This affects how the nylon behaves when heated or used.

Environmental impact

Nylons can break down when they come into contact with strong acids, which can cause the material to crack. To keep nylon safe during production, it must be dried well to prevent damage from water.

Making nylon can create greenhouse gases, similar to making wool, but nylon lasts longer, which helps reduce its overall impact on the environment. However, when nylon burns, it can release harmful fumes. Because recycling nylon is difficult and expensive, much of it ends up in landfills, where it can take many years to break down. Nylon from old fishing nets can harm ocean life, but some companies are working to recycle this material into new products.

Properties

Nylon is a special kind of plastic that can be shaped into many forms. When it is made into fibers, it can be very strong and stretchy. Nylon can also be made into smooth, silky fabrics.

Nylon comes in different types, each with its own qualities. Some types are very strong and good for things like seatbelts, while others are soft and good for clothing. Nylon can be dyed many colors and is often used in clothes, carpets, and even stockings. It is also used in many military items because it is strong and can resist damage from sunlight, insects, and chemicals.

Uses

Nylon was first used in a toothbrush in 1938 and then became famous for women's stockings shown at the 1939 New York World's Fair. Its use grew a lot during World War II because there was a big need for fabrics.

Nylon replaced natural materials like silk and hemp in things like parachutes, tires, tents, ropes, and other military supplies. After the war, nylon was used in carpets and car parts. It is also used in food packaging, like oven bags, and in filaments for things like toothbrushes and fishing lines. Nylon can be shaped into many forms, such as rods, tubes, and sheets, and is used in 3D printing.

Main article: Nylon