Condensation polymers are obtained by reacting two monomers with the elimination of a simpler substance.
This substance may be HCl, H2O, NH3, etc., sometimes by rearrangements between the monomer molecules.
Examples of condensation polymers are nylon, polyester, bakelite and polycarbonates.
Nylon is a polymer resulting from condensation of diamines with diacids. It is a polyamide (nylon-66).
It is widely used in textile fibers, fishing lines, etc.