Polükondensatsioonis

Polükondensatsioonis is a type of step-growth polymerization reaction where monomer units join together by eliminating smaller molecules, such as water, methanol, or hydrogen chloride. This process results in the formation of a polymer chain and the release of the byproduct. Unlike chain-growth polymerization, where monomers add sequentially to a growing chain, polükondensatsioonis involves reactions between functional groups on different monomer molecules.

The monomers used in polükondensatsioonis typically contain at least two reactive functional groups. For example, dicarboxylic acids and diols can react to form polyesters with the elimination of water. Similarly, diamines and dicarboxylic acids can form polyamides, also releasing water. The reaction proceeds in stages, with the formation of dimers, trimers, and eventually long polymer chains. The rate of polymerization is influenced by factors such as temperature, catalyst presence, and the concentration of reactants.

Polükondensatsioonis is a crucial method for synthesizing a wide range of important polymers, including polyesters (like PET), polyamides (like nylon), polycarbonates, and polyurethanes. These polymers find extensive applications in industries such as textiles, packaging, automotive, and construction due to their diverse properties, which can be tailored by the choice of monomers and reaction conditions. The molecular weight of the resulting polymer is controlled by the extent of the reaction and the removal of the small molecule byproduct.