Invention of nylon

Nylon (Nylon), named Polyamide in English, is a man-made polymer. Wallace Carothers of DuPont invented the plastic on February 28, 1935, in Wilmington, USA. Nylon was officially marketed in 1938. The first nylon products were nylon brushes for toothbrushes (sold on February 24, 1938) and nylon stockings for women (sold on May 15, 1940). The appearance of nylon makes the textile a new look, its synthesis is a major breakthrough in the synthetic fiber industry, but also a very important milestone in polymer chemistry.

The biggest advantages of nylon are strong wear resistance, low density, light fabric, good elasticity, fatigue damage resistance, chemical stability is also very good, alkali resistance and acid resistance. The biggest disadvantage is that the sun resistance is not good, the fabric will turn yellow after a long time in the sun, strength decline, moisture absorption is not good, but better than acrylic, polyester.

Classification of nylon

Nylon is named mainly by the number of carbon atoms in each repeating amide group. The first digit of the name refers to the number of carbon atoms in the binary amine, and the next digit refers to the number of carbon atoms in the binary carboxylic acid.

PA46

Its outstanding characteristics are high crystallinity, high temperature resistance, high rigidity, high strength. Mainly used for automotive engine and peripheral components, such as cylinder head, cylinder base, oil seal cover, transmission. In the electrical industry, it is used as contactor, socket, coil skeleton, switch and other fields requiring high heat resistance and fatigue strength.

PA4T

The melting point of pure PA4T resin is very high, which exceeds its decomposition temperature. If copolymerization modification is not carried out to reduce its melting point, it cannot be commercialized and it is extremely difficult to popularize. Therefore, the promotion of PA4T in the market generally requires copolymerization modification, and the common means is copolymerization with PA66 and/or PA6 to reduce the melting point. After modification, it has excellent mechanical properties, good fluidity, excellent electrical properties, outstanding chemical corrosion resistance and high temperature resistance, which can meet the requirements of electronic, electrical, mobile terminal and other fields.

PA56

English name: Polyamide56 or Nylon56; For short: PA56. Nylon 56 is a polycondensation of glutarenediamine and adipic acid. The extract of glutarenediamine can come from natural organisms.

Environmental protection, good performance, can improve the comfort of the terminal fabric. Its water absorption rate, glass transition temperature, strength, softness, moisture absorption, resilience are better than nylon 6, nylon 66, polyester part of the products.

PA6

Translucent or opaque opalescent resin, with superior mechanical properties, stiffness, toughness, wear resistance and mechanical shock absorption, good insulation and chemical resistance. Widely used in automotive parts, electronic and electrical components and other fields.

PA66

Compared with nylon 6, its mechanical strength, stiffness, heat and wear resistance, creep resistance is better, but the impact strength and mechanical shock absorption performance are decreased. It is widely used in automobile, UAV, electronic and electrical.

Semi-aromatic nylon

The transmittance of visible light reaches 85% ~ 90%. It is added in nylon components with copolymerization and three-dimensional barriers to inhibit the crystallization of nylon, resulting in non-crystalline and difficult to crystallize the structure, it maintains the original strength and toughness of nylon, and get transparent thick wall products. The mechanical properties, electrical properties, mechanical strength and rigidity of transparent nylon almost belong to the same level as PC and polysulfone.

PA6T

Its outstanding characteristics are high temperature resistance (melting point 370℃, glass temperature 180℃, can be used at 200℃ for a long time), high strength, stable size, good welding resistance, making PA6T especially suitable for adhesion technology (SMT) for electronic connectors. Mainly used in automobile parts, oil pump cover, air filter, heat resistant electrical parts such as wiring harness wiring board, fuse, etc.

MXD6

It is a crystalline polyamide produced by the condensation of m-benzoylamine mxda and adipic acid. Unlike nylon 6 and 66, nylon mxd6 is an aliphatic polyamide that contains an aromatic ring in its main chain.

Compared with nylon 6 and nylon 66, nylon MXD6 has the following favorable characteristics:
1. Greater strength and elastic modulus;
2. High glass transition temperature;
3. Low water absorption and moisture permeability;
4. Good crystallization speed and easy to form and manufacture;
5. Good gas barrier performance.

These characteristics have led to many different applications of nylon-mxd6 as a packaging and molding material, as well as the production of monofilaments.

PA610

It is translucent milky white. Its strength is between nylon 6 and nylon 66. Small proportion, low crystallizability, low water absorption, good dimensional stability, good wear resistance, self-extinguishing. Used for precision plastic parts, oil pipelines, containers, ropes, conveyor belts, bearings, textile machinery parts, electrical and electronic insulation materials and instrument shells.

PA9T

Its outstanding characteristics are: low water absorption, water absorption rate of 0.17%; Good heat resistance (melting point 308℃, glass transition temperature 126℃), its welding temperature up to 290℃. Mainly used in electronics, electrical appliances, information equipment and automotive parts.

PA10T

Its main characteristics are very low hygroscopicity, high temperature resistance, excellent toughness, rigidity and dimensional stability, good fluidity and processing performance, easy coloring, high strength welding fusion line, melting point up to 300~316℃, density of 1.42g/cm3. PA10T has benzene ring and a long flexible long chain of diamine, which makes the macromolecule have a certain degree of flexibility, and thus has a high crystallization rate and crystallinity, which is suitable for rapid prototyping. Widely used in LED reflection bracket, motor end cover, brush bracket, gear and so on.

PA1010

Its biggest characteristic is that it has a high ductility, can be stretched to 3 ~ 4 times the original length, and high tensile strength, impact and low temperature is excellent, not brittle at -60℃, at the same time has excellent wear resistance, ultra-high toughness and good oil resistance, widely used in aerospace, cable, optical cable, metal or cable surface coating.

PA11

It is a white semi-transparent body. Its outstanding characteristics are low melting temperature and wide processing temperature, low water absorption, good low temperature performance, can be maintained in -40℃ ~ 120℃ good flexibility. Mainly used in automobile oil pipeline, brake system hose, fiber optic cable coating, packaging film, daily necessities, etc.

PA12

It is similar to nylon 11 but has lower density, melting point and water absorption than nylon 11. Because it contains a large amount of toughening agent, it has the property of combining polyamide and polyolefin. Its outstanding characteristics are high decomposition temperature, low water absorption and good low temperature resistance. Mainly used in automobile oil pipeline, instrument panel, accelerator pedal, brake hose, electronic and electrical muffler parts, cable sheathing.

PA1212

It is obtained by polycondensation of twelve diamine and twelve diacetic acid. PA1212 has the lowest water absorption rate in nylon, good dimensional stability, good oil resistance, alkali resistance, wear resistance, chemical resistance, good transparency, excellent toughness at low temperature. Widely used in aerospace, automobile, textile, instrument, medical equipment and so on.

Aramid 1313

Nomex has mechanical properties and heat resistance that are much higher than aliphatic PA (as a fiber fabric, its life is 8 times longer than aliphatic PA fiber cloth and 20 times longer than cotton fabric), good heat resistance aging (surface resistivity and volume resistance remain unchanged after thermal aging at 250℃ for 2000h), and good electrical properties can still be maintained under high temperature or humid environment. Mainly used for H class electrical insulation materials and preparation of high performance fiber (HT-1 fiber).

PA1414

The molecule is mainly composed of rigid benzene ring, which belongs to the high rigidity polymer. Its molecular structure has a high degree of symmetry and regularity, and there is a strong hydrogen bond between the large molecular chains, which makes the polymer has the characteristics of high strength, high modulus, high temperature resistance, low density, small thermal shrinkage, good dimensional stability and so on. It can be made into high strength and high modulus fiber.