Polymers materials can undergo long term, irreversible microstructure changes due to oxidation/hydrolysis/biodegradation, which will inevitably lead to embrittlement and ultimately make them unsuitable for an application requiring mechanical strength. Predicting and extending the lifetime of systems based on such materials is a major challenge today, as it directly addresses issues related to global environmental impact and waste management.

To predict the lifetime of polymers, it is necessary to identify structure-property relationships of the materials as they undergo a process of majority chain scission. In particular it is crucial to identify new macromolecular criteria governing the experimentally observed embrittlement using a multi-scale approach. This involves detailed characterization of the microstructure (using XR measurements) alongside a relevant characterization of the mechanical behaviour at fracture.

The objective of this internship is to characterize and understand the impact of aging on the microstructures of polymers using X-ray techniques. The study will first involve conducting SAXS and WAXS tests on aged samples, focusing on two types of polymers: polyurethanes and a biodegradable polymer (polybutylene succinate). In the second phase, the microstructural changes will be correlated with variations in mechanical behavior to better understand the origin of embrittlement during aging.

Publié le 03/11/2024