What is Nylon Plastic?

Definition of Nylon Plastic

What is nylon plastic? Nylon, chemically known as polyamide (PA), is also known as polyurethane fiber, the world’s first synthetic fiber. It is a general term for thermoplastic resins containing repeating amide groups in their molecular backbone. Therefore, there are many types of nylon, not just one specific substance. These include aliphatic PA, aliphatic-aromatic PA, and aromatic PA. Aliphatic PAs are numerous, have high production volumes, and are widely used. Therefore, their name is determined by the specific number of carbon atoms in their synthetic monomers.

The history of nylon plastics

Research on synthetic polyamides dates back to 1928. In 1935, American scientist Carothers and his collaborators, while conducting theoretical research on polycondensation reactions, produced a high-molecular-weight linear polycondensate, polyhexamethylene adipamide (polyamide 66), in their laboratory from adipic acid and hexamethylenediamine.

From 1936 to 1937, DuPont, based on Carothers’s research, melt-spinned polyamide 66 fiber, naming it nylon. This was the first polyamide, and industrial production began in 1939. Separately, Schlack of Germany invented the synthesis of polycaprolactam (polyamide 6) from caprolactam in 1938, along with fiber production technology, which began industrial production in 1941.

After more than half a century of development, many polyamide products have emerged. Aliphatic polyamides (PA) include PA-6, PA-610, PA-612, PA-1010, PA-11, PA-12, and PA-46.
Aromatic polyamides include poly(p-phenylene terephthalamide) fiber, commonly known as aramid 1414 in my country, and poly(m-phenylene isophthalamide) fiber (known as aramid 1313 in my country).
Blended polyamides include poly(m-phenylene adipamide) (MXD16) and poly(hexamethylene terephthalamide) (polyamide 6T).

Characteristics of nylon plastic

Excellent mechanical properties, high mechanical strength, and good toughness. As a synthetic fiber, nylon’s most prominent advantage is its abrasion resistance, surpassing all other fibers—10 times greater than cotton and 20 times greater than wool. Adding a small amount of polyamide fiber to blended fabrics can significantly improve wear resistance. When stretched to 3-6%, its elastic recovery can reach 100%, and it can withstand tens of thousands of flexing cycles without breaking.
Self-lubricating and excellent friction resistance: Nylon has excellent self-lubricating properties and a low coefficient of friction.
Heat resistance: Excellent weather resistance.
Electrical insulation Nylon has high volume resistivity and a high breakdown voltage, making it an excellent insulating material for electrical and electronic appliances.
Water absorption Nylon’s high water absorption can easily lead to changes in the dimensions and performance of finished products. However, the polyamide macromolecules contain terminal amino and carboxyl groups at their ends, which can exhibit a certain degree of reactivity under certain conditions. Therefore, chemical and physical modifications can be carried out through methods such as blocking, grafting, blending, reinforcement and filling to overcome the changes in size and performance caused by high water absorption.

Applications of nylon plastics

Nylon brush filaments, made by melting and drawing nylon, are characterized by their high toughness, excellent wear resistance, and strong resilience. They are widely used in:
Personal Care Industry: Such as toothbrush filaments, hair comb filaments, and makeup brush filaments;
Household Cleaning Industry: Such as vacuum cleaner filaments, clothes brush filaments, shoe brush filaments, and pot scrubber filaments;
Industrial Industry: Such as glass polishing filaments, escalator brush filaments, and roller brush filaments.