Chemical aging of polymers

With the massive and ever-increasing use of plastics, and the need to control the risk of failure while optimizing the development costs of an industrial part, it has become necessary to rigorously address issues relating to the ageing of a polymer part under service conditions. It should be pointed out that the expected service life of a polymer part often makes prediction based exclusively on observation in service conditions incompatible with the requirements of Research and Development departments.

As a result, engineers need reliable simulation tools to predict material service life, and possibly propose more appropriate formulations, without having to resort to lengthy and costly testing campaigns. Tools already exist for selecting materials to meet specific requirements, and for sizing parts accordingly. However, the part's resistance to creep, for example, can no longer be guaranteed if chemical modifications induced by the material's interactions with its environment cause its properties to evolve beyond an acceptable threshold.

A series of dossiers is dedicated to aging processes resulting primarily from changes in the chemical structure of polymer materials.

Any prediction of service life must be based on kinetic analysis of the chemical processes at work. However, the study of chemical ageing is of practical interest because the resulting structural modifications translate into changes in the physical properties of use. Any durability study must therefore include a "structure – properties" section.

The main degradation mechanisms are the subject of this first dossier [AM3151v2].

The next two dossiers deal with kinetic modeling [AM3152v2] and stabilization strategies [AM3153v2] .