Liyang Sun

Polyamide

Polyamide is basically a big word for nylon, and is essentially an organic thermoplastic.There are different types of polyamides that have specific functions and properties.For example polyamide 6 is known for its elasticity, dyability and recyclability while polyamide 6.6 is known for its heat resistance, rigidity, dimensional stability and abrasion resistance.Polyamide (nylon) was considered to be the, or on of the first completely manmade fiber.The history leading up to the discovery of nylon began from as far back as 1664 when a Chinese emperor developed a project to manufacture synthetic yarn.In 1884, Earl Hilarie Bernigaud de Chardonnet discovered nitrocellulose fiber, or synthetic silk, and showed his discovery at the Paris Universal Exhibition in 1889.Following that in 1891, Cross, Bevan and Beadley, three English chemists, succeeded in diluting cellulose through xanthogene, which made it possible to spun cellulose.A major contributor to the manufacture of synthetic fibres by polymerization is German professor Hermann Staudinger.He demonstrated in 1925 the existence of macromolecules, which proves that natural fibres are made by large linear molecules.Even though there is so much pervious research, the person who truly discovered nylon (polyamide 6.6) is Dr. Wallace Hume Carothers in 1933, who lead a team of researchers for Dupont.Polyamide 6 was discovered in 1936 by Paul Slack and sold as Perlon.Also in 1936 Pechiney found polyamide 11, or Rilsan.

A one if the chemical reaction that makes Nylon (a polyamide) combindes hexamethylenediamine and sebacoyl chloride. The product is called 6- 10 nylon and consists of alternating units contributed by the hexamethylened iamine (6 carbon atoms) and the sebacoyl chloride (10 carbon atoms).The name comes from the number of carbon atoms in the repeating units, 6 and 10 in this case. There are other types of Nylons in which the repeating units contain numbers of carbon atoms different from 6 and 10. For example, an important commercial Nylon is called '6-6' in which each repeating unit contains 6 carbon atoms. Incidently, the repeating units also contain hydrogen (H), nitrogen (N), and oxygen atoms (O) in addition to carbon (C) atoms.

Polyamide is used in several areas. For automotive purpose, polyamide helps to reduce the weight of cars, which cuts both fuel consumptions and pollutions.The material is also found in the cooling system, air circulation system, engine parts and electrical components.More products that uses polyamide are rear view mirors, hubcaps and tires.The polyamide found under the carhod is indispensable in the air and cooling sustems, housing and air conditioning.The characteristics that allow polyamide to withstand sudden increase in temperature are : heat endurance, incomparable chem resistant and good mechanical properties.Polyamide also play a role in all the electrical and electronic equiptments used in cars.It offers reliability and durability and contributes to the efficiency of a car's electronic network.Inside the car, there are also many forms of polyamide present.The cabins, dashboard, ashtray and other devices are all made from polyamide.It is also the yarn used to make airbags. Of course, one of the biggest areas where polyamide /nylon is used is the clothing industry.Not only has everyday clothing adapted polyamide, even gears of firefighters, anti-riot garments, and protective jackets of chemical plants uses polyamide because of its resistance against heat and chemicals.Not only that, polyamide made clothing offer more protection, are lighter, more comfortable and more durable than clothes made from natural materials.

The electrical and electronic industry also makes much of its products using polyamide.It offers an excellent compromise between strength, flexibility, and fire resistance with properties that make it easily processable as insulation for electric wires.Polyamide / nylon is also widely used for items like gears and bearings due to its low friction and high wear resistance and is often used as a replacement for metals such as bronze, aluminum, brass, and steel. It is also used to replace wood, rubber, and other kinds of plastics.In the carpeting business polyamide is also a major player because of it's resistances and ability to absorb sound.Along with carpets polyamide is also used in wallcoverings and soundproofing materials.

Polyamide is also found in sporting utilities such as: Mountain bikes, goggles, skis, fishing lines, hang gliders.All these equipments rely on the flexibility, lightweight and high-strength of polyamides.As we head into the future, polyamide will certainly be used even more extensively in all areas, including medical applications.Already it is used in blood transfusion, dialysis, and heart surgery.One example is a blood filter which is made from polyamide yarns that satisfy the demand for total purity of blood during the transfusion phase. Considering the vast amount of possibilities for polyamide now, the potential for its usage will certainly grow over time.Not only that, a mixture of synthetic materials with polyamide can produce desired effects that polyamide itself does not have.We can only experiment with the endless possibilities in order to create a better type of polyamide.