Polymers and composites are ubiquitous in our daily lives, enabling, for example, lighter structural materials and food packaging. Their performance depends not only on their chemical structure, synthesis, architecture and shaping process, but also evolves over time under the effect of processes that modify the structure of the material – sometimes slowly but irreversibly. Users must therefore consider the maximum period of use during which these materials retain acceptable levels of properties. This question is even more crucial as it responds to societal demands related to limiting end-of-life waste flows and preserving the resources needed to produce them. To address these challenges, Aging of Industrial Polymers 2 provides designers with tools to analyze the mechanisms of material degradation under given conditions of use, develop models to predict the rate of degradation, and understand the effect of phenomena occurring at the molecular level on the macroscopic properties of the material.