Monomerer

Monomerer are small molecules capable of covalently bonding to form larger macromolecules called polymers. In polymer chemistry, a monomer unit provides a reactive site that links with others to create repeating units along a polymer chain. Polymers may consist of identical monomers (homopolymers) or different monomers (copolymers).

Two main classes of monomers are distinguished by how they form polymers. Addition or chain-growth monomers, such as vinyl compounds with carbon–carbon double bonds, polymerize without eliminating small molecules. Condensation or step-growth monomers react to form polymers while releasing a byproduct such as water or methanol. Natural monomers include amino acids, nucleotides, and simple sugars that assemble into biopolymers like proteins, nucleic acids, and polysaccharides.

Common synthetic monomers include ethylene, propylene, styrene, vinyl chloride, acrylics, and lactic acid derivatives. The reactive group and molecular functionality (the number of reactive sites) determine polymer architecture: difunctional monomers yield linear chains, while trifunctional or higher functionality can create crosslinked networks. Stereochemistry and purity also influence material properties.

Polymerization methods vary from radical, cationic, and anionic processes to condensation with catalysts. Controlled radical polymerization techniques enable more precise control over molecular weight and architecture. The choice of monomer and polymerization conditions affects properties such as strength, elasticity, thermal stability, and compatibility with other materials.

Monomers underpin a wide range of materials, from everyday plastics to fibers, elastomers, resins, hydrogels, and biopolymers used in medicine and biotechnology.