—monomeric /mon'euh mer"ik/, adj./mon"euh meuhr/, n. Chem.a molecule of low molecular weight capable of reacting with identical or different molecules of low molecular weight to form a polymer.[1910-15; MONO- + -MER]
* * *Molecule of any of a class of mostly organic compounds that can react with other molecules of the same or other compounds to form very large molecules (polymers).The essential feature of monomer molecules is the ability to form chemical bonds (see bonding) with at least two other monomer molecules (polyfunctionality). Those able to react with two others can form only chainlike polymers; those able to react with three or more can form cross-linked, network polymers. Examples of monomers (and their polymers) are styrene (polystyrene), ethylene (polyethylene), and amino acids (proteins).
* * *a molecule of any of a class of compounds, mostly organic, that can react with other molecules of the same or other compound to form very large molecules, or polymers. The essential feature of a monomer is polyfunctionality, the capacity to form chemical bonds to at least two other monomer molecules. Bifunctional monomers can form only linear, chainlike polymers, but monomers of higher functionality yield cross-linked, network polymeric products.Addition reactions are characteristic of monomers that contain either a double bond between two atoms or a ring of from three to seven atoms; examples include styrene, caprolactam (which forms nylon-6), and butadiene and acrylonitrile (which copolymerize to form the synthetic rubber Buna N). Condensation polymerizations are typical of monomers containing two or more reactive atomic groupings; e.g., a compound that is both an alcohol and an acid can undergo repetitive ester formation involving the alcohol group of each molecule with the acid group of the next, to form a long-chain polyester. Similarly, hexamethylenediamine, which contains two amine groups, condenses with adipic acid, which contains two acid groups, to form the polymer nylon-6,6.
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