Chemical reaction that leads to the formation of ring structures in or from polymer chains.
Notes: - Examples of @C01494@ along polymer chains are: (a) @C01494@ of polyacrylonitrile, (b) acetalization of poly(vinyl alcohol) with an aldehyde, (c) @C01494@ of polymers of conjugated @D01699@, such as polyisoprene or polybutadiene, leading to macrocycles.
- Examples of @C01494@ of polymer molecules are: (a) @C01494@ of poly(dimethylsiloxane), (b) back-biting reaction during ionic polymerizations of heterocyclic monomers.
Source:
PAC, 2004, 76, 889. 'Definitions of terms relating to reactions of polymers and to functional polymeric materials (IUPAC Recommendations 2003)' on page 893 (https://doi.org/10.1351/pac200476040889)