Dreifunktionelle

Dreifunktionelle is a term used in chemistry and materials science to describe molecules or polymers that bear three reactive functional groups. These groups are sites where chemical bonds can form, allowing branching and crosslinking within a material. The term is commonly encountered in German-language texts and is related to the concepts of monofunctional, difunktionell, and tetrafunctional compounds.

In polymer and resin chemistry, trifunctional components act as crosslinking points that connect three polymer chains or network segments. This threefold connectivity increases network density, influencing properties such as gelation behavior, mechanical strength, thermal stability, and the glass transition temperature. Compared with bifunctional reagents, trifunctional agents typically yield more highly crosslinked, potentially more rigid and less soluble networks.

Common examples include glycerol, which has three hydroxyl groups, trimethylolpropane (TMP), and triethanolamine. Tri-functional reagents also appear as carboxyl-, acrylate-, or isocyanate-bearing compounds such as trimesic acid or trimethylolpropane triacrylate, used as crosslinkers in polyesters, epoxies, and polyurethane systems. The selection of a dreifunktionelle component depends on the desired balance of crosslink density, processing, and final material properties.

Outside polymer synthesis, the term can apply to any molecule with three reactive sites used for covalent modification, bioconjugation, or network formation. Overall, dreifunktionelle describes a key aspect of multifunctionality that enables branching, network formation, and tailored material performance.