Chemical changes in a @M03667@ material that usually result in undesirable changes in the in-use properties of the material.
- In most cases (e.g., in vinyl polymers, polyamides) degradation is accompanied by a decrease in molar mass. In some cases (e.g., in polymers with aromatic rings in the main chain), degradation means changes in chemical structure. It can also be accompanied by @CT07136@.
- Usually, degradation results in the loss of, or deterioration in, useful properties of the material. However, in the case of @B00656@ (degradation by biological activity), polymers may change into environmentally acceptable substances with desirable properties.