Chain scission is a term used in

polymer chemistry Polymer chemistry is a sub-discipline of chemistry that focuses on the structures of chemicals, chemical synthesis, and chemical and physical properties of polymers and macromolecules. The principles and methods used within polymer chemistry are ...

describing the degradation of a

polymer main chain A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and ...

. It is often caused by

thermal stress In mechanics and thermodynamics, thermal stress is mechanical stress created by any change in temperature of a material. These stresses can lead to fracturing or plastic deformation depending on the other variables of heating, which include mat ...

(heat) or ionizing radiation (e.g. light,

UV radiation Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

gamma radiation A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically s ...

), often involving

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...

. 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, . Depolymerization, on the other hand, is the elimination of low molecular weight substances (

monomer In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification ...

s, dimers and suchlike) from a polymer.Otto-Albrecht Neumüller (Herausgeber): ''Römpps Chemie Lexikon'', Frank’sche Verlagshandlung, Stuttgart, 1983, 8. Auflage, S. 891, .

References

{{Reflist Chemical reactions Biochemistry