in polymer chemistry
Also contains definition of: covalent network
https://doi.org/10.1351/goldbook.N04112
A highly ramified
macromolecule
in which essentially each
constitutional unit
is connected to each other
constitutional unit
and to the macroscopic phase boundary by many permanent paths through the macromolecule, the number of such paths increasing with the average number of intervening bonds; the paths must on the average be co-extensive with the macromolecule.
Notes:
  1. Usually, and in all systems that exhibit rubber elasticity, the number of distinct paths is very high, but, in most cases, some constitutional units exist which are connected by a single path only.
  2. If the permanent paths through the structure of a
    network
    are all formed by covalent bonds, the term covalent network may be used.
  3. The term
    physical network
    may be used if the permanent paths through the structure of a
    network
    are not all formed by covalent bonds but, at least in part, by physical interactions, such that removal of the interactions leaves individual macromolecules or a macromolecule that is not a
    network
    .
Source:
PAC, 1996, 68, 2287. (Glossary of basic terms in polymer science (IUPAC Recommendations 1996)) on page 2298 [Terms] [Paper]