Study of the influence of stretching on the macromolecular dynamics of polylactide by means of Xray Photon Correlation Spectroscopy (XPCS) m

The goal of this proposal is twofold. On the one hand it aims at improving the previously developed setup allowing simultaneous WAXS/XPCS measurements besides by adding a SAXS detector in order to track the structural evolution at the nanometer scale. On the other hand, the goal is to consolidate the previously carried out measurements and to go deeper in order to answer the remaining questions. In this way, one aim is to determine if the slowdown of the relaxation times observed with the increase of crystallinity arises from a constraining effect due to the formation of crystalline lamellae and/or originates from an increase of nanoparticles concentration (i.e. tracers) into the amorphous domains involved by a segregation effect. Also, more precise and exhaustive measurements will be carried out on stretched samples in order to confirm the fact the dynamics heterogeneities and to determine the critical orientation degree above which they are observed.