Page 394 - Handbook of Properties of Textile and Technical Fibres

The chemistry, manufacture, and 12

tensile behavior of polyamide
fibers

Ji rí Militký, Mohanapriya Venkataraman, Rajesh Mishra
Technical University of Liberec, Liberec, Czech Republic

12.1 Introduction

Polyamides are tough, strong, and durable polymers useful in a wide range of industrial
applications. Aliphatic PA 6 and PA 66 are the most widely used polyamides for
fibers and for engineering materials. Aliphatic polyamides with structural units derived
predominantly from aliphatic monomers are members of the generic class of nylons,
whereas, aromatic polyamides, in which at least 85% of the amide linkages are directly
adjacent to aromatic structures, have been designated aramids (Richards, 2005). The
nylons are generally tough, strong, durable fibers, useful in a wide range of textile
applications. The distinguishing characteristics are being highly elastic, tear and
abrasion resistant, having low humidity absorption capability, fast drying, no loss of
solidity in a wet condition, crease-resistant, and rot and seawater proof. Some of the
applications of polyamides include fine stockings, outer sporting and motorcycle
garments, female underclothes, ropes, and parachutes.
The number of carbon atoms in each monomer or comonomer unit is commonly
designated for nylons (according to the standard, it is abbreviated PA). The two
main types of fibers are PA 6, usually known as Perlon (or Nylon 6), and PA 66, which
is generally called Nylon. The number or numbers after the word “polyamide” or “PA”
indicate how many carbon atoms there are in each monomeric unit. The fact that there
is only one number in one instance and two in the other shows that PA 6 contains
only one monomer and polyamide 66 contains two, with six carbon atoms in each
monomeric unit (Richards, 2005; Deopura et al., 2008).
The development of nylon started in 1927 by many researchers, notable among them
were W.H. Carothers and P. Schlack. Nylon (PA 66) was first produced in the DuPont
USA laboratory in 1935 by Gerard Berchet, which started commercial production in
1937 (Carothers, February 1937). DuPont announced nylon as the first synthetic fiber
on October 27, 1938, completed the pilot plant in Wilmington, Delaware, in July
1938, and introduced nylon to the market as Exton bristles for Dr. West’stoothbrushes
(Najafi et al., 2017a). In 1939, the introduction of nylon into sheer stockings revolution-
ized the women’s hosiery market. Paul Schlack polymerized caprolactam to PA 6 and
wasgranted a patentin1941assignedtoI.G.Farbenindustrie (U.S. Pat. 2241321).
PA 6 was developed and commercially introduced as Perlon in 1940 in Germany.

Handbook of Properties of Textile and Technical Fibres. https://doi.org/10.1016/B978-0-08-101272-7.00012-2
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