Nylon (polyamide) is a synthetic fiber, polydiamine diamine obtained by condensation of diamine and diacid. The relative molecular weight of this type of nylon is generally 17000-23000. Depending on the number of carbon atoms of the diamine and dibasic acid used, different nylon products can be obtained.
It can be distinguished by the number added after the nylon, where the first number is the number of carbon atoms of the diamine, and the latter number is the number of carbon atoms of the dibasic acid. For example, nylon 66 indicates that it is made by the polycondensation of hexamethylenediamine and adipic acid; nylon 610 indicates that it is made from hexamethylenediamine and sebacic acid.
Uses
Nylon is mainly used for synthetic fibers. Its most prominent advantage is that its wear resistance is higher than that of all other fibers, 10 times higher than cotton and 20 times higher than wool. times, adding a little polyamide fiber to the blended fabric can greatly improve its wear resistance; when stretched to 3-6, the elastic recovery rate can reach 100; it can withstand tens of thousands of bends without breaking.
The strength of polyamide fiber is 1-2 times higher than cotton, 4-5 times higher than wool, and 3 times stronger than viscose fiber. However, polyamide fiber has poor heat resistance and light resistance, as well as poor retention, and the clothes made from it are not as crisp as polyester.
In addition, nylon-66 and nylon-6 used for clothing have the disadvantages of poor hygroscopicity and dyeability. For this reason, new varieties of polyamide fibers-nylon-3 and nylon-4 have been developed. The new polyamide fiber has the characteristics of light weight, excellent wrinkle resistance, good breathability, good durability, dyeability and heat setting, so it is considered to be very promising.
In industry, nylon is widely used to make cords, industrial fabrics, cables, conveyor belts, tents, fishing nets, etc. Mainly used in national defense as parachutes and other military fabrics.