polycondensaatioreaktioihin

Polycondensation reactions are a class of polymerization processes where monomers react to form a polymer with the simultaneous elimination of a small molecule, such as water, methanol, or hydrogen chloride. This is in contrast to addition polymerization, where monomers add to one another without the loss of any atoms. The characteristic feature of polycondensation is the formation of a new functional group as the monomer units link together. For example, the reaction between a dicarboxylic acid and a diamine forms a polyamide, with water being eliminated. Similarly, the reaction between a diol and a dicarboxylic acid yields a polyester, also with water as a byproduct.

The rate of polycondensation reactions is often dependent on the concentration of the reacting functional groups and can be influenced by catalysts. The molecular weight of the resulting polymer is controlled by the stoichiometry of the reacting monomers and the extent of the reaction. Incomplete reactions or unequal molar amounts of reactants will limit the chain length. These reactions are fundamental to the synthesis of many important industrial polymers, including nylons, polyesters like PET, and polycarbonates. The specific small molecule eliminated is determined by the types of functional groups involved in the polymerization.