Chain scission

{{Short description|A chemical reaction resulting in the breaking of skeletal bonds.}}

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|title = IUPAC definition

|quote = chain scission: A chemical reaction resulting in the breaking of skeletal bond.{{cite journal |title=chain scission |url=https://goldbook.iupac.org/terms/view/C00961 |website=Gold Book |date=2014 |publisher=IUPAC |access-date=1 April 2024 |ref=Gold Book C00961 |doi=10.1351/goldbook.C00961|doi-access=free }}}}

Chain scission is a term used in polymer chemistry describing the degradation of a polymer main chain.{{GoldBookRef|title=chain scission|file=C00961|doi=10.1351/goldbook.C00961}} It is often caused by thermal stress (heat) or ionizing radiation (e.g. light, UV radiation or gamma radiation), often involving oxygen. During chain cleavage, the polymer chain is broken at a random point in the backbone to form two - mostly still highly molecular - fragments.Sebastian Kotzenburg, Michael Maskus, Oskar Nuyken: Polymere – Synthese, Eigenschaften und Anwendungen, Springer Spektrum, 2014, S. 440–441, {{ISBN|978-3-642-34772-6}}.

Depolymerization, on the other hand, is the elimination of low molecular weight substances (monomers, dimers and suchlike) from a polymer.Otto-Albrecht Neumüller (Herausgeber): Römpps Chemie Lexikon, Frank’sche Verlagshandlung, Stuttgart, 1983, 8. Auflage, S. 891, {{ISBN|3-440-04513-7}}.