Number of covalent bonds that a @[email protected] or monomeric unit in a macromolecule or @[email protected] can form with other reactants.
  1. There are no monofunctional monomers.
  2. If \(f = 2\), a @[email protected] macromolecule or a @[email protected] can be formed.
  3. If \(f > 2\), a branch point can be formed leading to a branched macromolecule, a @[email protected] or a micronetwork.
  4. Ethene and ethylene glycol are examples of difunctional monomers, glycerol is an example of a trifunctional @[email protected], and divinylbenzene and pentaerythritol are examples of tetrafunctional monomers.
PAC, 2007, 79, 1801. (Definitions of terms relating to the structure and processing of sols, gels, networks, and inorganic-organic hybrid materials (IUPAC Recommendations 2007)) on page 1805 [Terms] [Paper]