The Mechanism of Condensation-Polymerization
Condensation-Polymerization is a process where Monomers with multiple Functional-Groups react to form a Polymer chain, while simultaneously releasing small molecules as byproducts, such as Water, Methanol, or Ammonia. This reaction mechanism is a form of Step-Growth-Polymerization, where the molecular weight of the polymer increases steadily throughout the reaction as dimers, trimers, and Oligomers react with one another. This contrasts with Addition-Polymerization, in which the entire Monomer molecule is incorporated into the polymer without the loss of any atoms.
Industrial and Biological Significance
Many essential synthetic materials are produced via Condensation-Polymerization. A primary example is the production of Polyamides like Nylon-6,6, which is synthesized from Adipic-Acid and Hexamethylenediamine. Another critical application is the formation of Polyesters, such as Polyethylene-Terephthalate (PET), used extensively in the textile and packaging industries. In biological systems, Condensation-Polymerization is the fundamental process for synthesizing Proteins from Amino-Acids, resulting in the formation of Peptide-Bonds. Other natural polymers like Cellulose and Starch are also formed through similar condensation processes.
Technical details on these chemical pathways can be found at Encyclopedia Britannica and the IUPAC Gold Book.