Homopolymer polyamides derived from pairs of diamines and diacids (or diacid derivatives). Maleic Anhydride is a commonly used raw material with diacid functionality. Later Flory (1946) proposed an improved synthesis of aliphatic polyesters with diacid chloride. It is the diacid chloride derivative of glutaric acid. It is the acyl chloride derivative of succinic acid and a simple diacid chloride. In addition, lysine at position 26 is in its derivative form (acylated with stearic diacid). The name can be abbreviated to diacid. Short aliphatic dialdehydes are sometimes named after the diacid from which they can be derived. The diacid is produced industrially by oxidation waste sugars. The diacid is converted to the diamine via the dinitrile.