Difference between nylon 66 and nylon 6

The main variety of nylon is the aliphatic polyamide fibre, which can be synthesised from one monomer, such as a lactam or an amino acid. At this time, the arabic numerals after the name of nylon, that is, the number of carbon atoms used in the lactam or amino acid, such as nylon 6, nylon 11, etc.; can also be synthesised with two monomers, that is, a diamine and a dicarboxylic acid. At this time, nylon name after the two groups of Arabic numerals, the first group represents the number of carbon atoms of the diamine, the second group represents the number of carbon atoms of the dibasic acid, such as nylon 66, nylon 610, nylon 1010 and so on.
Generally speaking, Nylon 66 feels better than Nylon 6, and Nylon 66 is also more comfortable than Nylon 6, but it is difficult to distinguish Nylon 6 from Nylon 66 on the surface.
Nylon 6 products have the characteristics of high strength, abrasion resistance, softness and mildness to the touch of the skin, and have a wide range of applications in the field of garments, silk, umbrellas, fishnet yarns, cordage, BCF carpet yarns and engineering plastics.
The polymerisation degree of nylon 6 is 140~200, and the polymerisation degree of nylon 66 is 55~77.
Nylon molecular chain contains a large number of amide groups, and adjacent molecular chain of amide groups can form a strong attraction of hydrogen Jian, chain segment a CH2-CH2 - has excellent flexibility, molecular chain structure is relatively neat, no huge side groups, the molecular chain is easy to form a crystalline when stretching, its crystallinity is 50% ~ 60%. Nylon is made by melt spinning method, the morphology under the microscope is similar to polyester, the cross-section is round, the longitudinal direction is smooth and straight. The density is small, about 1.14g/cm3.