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Polymer degradation is the reduction in the physical properties of a polymer, such as strength, caused by changes in its chemical composition.Polymers and particularly plastics are subject to degradation at all stages of their product life cycle, including during their initial processing, use, disposal into the environment and recycling. [1]
In polymers, such as plastics, thermal degradation refers to a type of polymer degradation where damaging chemical changes take place at elevated temperatures, without the simultaneous involvement of other compounds such as oxygen. [1] [2] Simply put, even in the absence of air, polymers will begin to degrade if heated high enough. It is ...
Here, is the density and k d is known as the specific surface degradation rate (SSDR), which changes depending on the polymer sample's chemical composition and weathering environment. Furthermore, for a microplastic sample, SA is often approximated as the surface area of a cylinder or sphere.
Polymer degradation is a change in the properties—tensile strength, color, shape, or molecular weight—of a polymer or polymer-based product under the influence of one or more environmental factors, such as heat, light, and the presence of certain chemicals, oxygen, and enzymes.
These elementary chemical reactions lead more or less quickly to a deterioration of the physical properties of polymer materials and their precise analysis using infrared spectroscopy methods makes it possible both to understand the degradation mechanism and to make predictions about the long-term behavior of polymers.
In the chemical industry, many organic chemicals are produced by autoxidation: in the cumene process, isopropylbenzene undergoes autoxidation to give cumene hydroperoxide. This compound is then converted to phenol and acetone, both commodity chemicals. are made from benzene and propylene. Many variations of this reaction have been developed, e ...
It is somewhat different from polymer degradation in that stress cracking does not break polymer bonds. Instead, it breaks the secondary linkages between polymers. These are broken when the mechanical stresses cause minute cracks in the polymer and they propagate rapidly under the harsh environmental conditions. [8]
Chain scission is a term used in polymer chemistry describing the degradation of a polymer main chain. [2] It is often caused by thermal stress (heat) or ionizing radiation (e.g. light, UV radiation or gamma radiation), often involving oxygen.