Editing Polyamide (section)

==Classification==
Polymers of [[Amino acid|amino acids]] are known as [[polypeptides]] or [[proteins]].

According to the composition of their main chain, synthetic polyamides are classified as follows:

{| class="wikitable"
|-
! Family !! Main chain !! Examples !! Commercial products
|-
| [[Aliphatic compound|Aliphatic]] polyamides || Aliphatic || [[Nylon]] [[Nylon 6|PA 6]] and [[Nylon 6-6|PA 66]] || [[Zytel]] from [[DuPont]], Technyl from [[Solvay (company)|Solvay]], Rilsan and Rilsamid from [[Arkema]], Radipol from [[Radici Group]]
|-
| [[Polyphthalamide]]s ||Semi-aromatic || PA 6T = [[hexamethylenediamine]] + [[terephthalic acid]] || Trogamid T from [[Evonik]] Industries, Amodel from [[Solvay (company)|Solvay]]
|-
| Aromatic polyamides, or [[aramid]]s || Aromatic || [[Paraphenylenediamine]] + terephthalic acid || [[Kevlar]] and [[Nomex]] from DuPont, Teijinconex, [[Twaron]] and [[Technora]] from [[Teijin Aramid]], Kermel from Kermel.
|}

All polyamides are made by the formation of an amide function to link two molecules of monomer together. The monomers can be amides themselves (usually in the form of a cyclic lactam such as [[caprolactam]]), α,ω-amino acids or a stoichiometric mixture of a diamine and a diacid. Both these kinds of precursors give a homopolymer. Polyamides are easily copolymerized, and thus many mixtures of monomers are possible which can in turn lead to many copolymers. Additionally many nylon polymers are miscible with one another allowing the creation of blends.