A polyamide is a
polymercontaining monomers of amides joined by peptide bonds. They can occur both naturally, examples being proteins, such as wooland silk, and can be made artificially, examples being nylons, aramids, and sodium poly(aspartate).
Production from monomers
The amide link is produced from the
condensation reactionof an aminogroup and a carboxylic acidor acid chloridegroup. A small molecule, usually water, or hydrogen chloride, is eliminated.
The amino group and the carboxylic acid group can be on the same monomer, or the polymer can be constituted of two different
bifunctionalmonomers, one with two amino groups, the other with two carboxylic acid or acid chloride groups. Amino acids can be taken as examples of single monomer (if the difference between R groups is ignored) reacting with identical molecules to form a polyamide: Aramid(pictured below) is made from two different monomers which continuously alternate to form the polymer and is an aromatic polyamide:
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