DCO fatty acids consist essentially of isomeric linoleic acid,which possess excellent drying properties since the usual cause of yellowing is the presence of linolenic acid. The usefulness of DCO fatty acids arises from the fact that the carboxyl group as well as the double bonds of the isomeric linolenic acids serves as reactive points, and the high degree of conjugation gives the double bond very high reactivity. DCO fatty acids with high content of diene conjugation could be dimerised at relatively lower temperatures and much faster than non-conjugated dienic acid to get dimmer acids which are intermediates in the manufacture of a variety of polyamide resins. DCO fatty acids can also be used for the preparation of a veriety  of polycarboxylic acids by Diels-Aldr type reaction.