Ultimate performances of technical polymer are most of the time related to the phases present as well as the level of crystallinity. Most of time, when metastable states are encountered, complete thermal path from synthesis up to final state has to be taken into consideration. Hence, process departments determine empirical routes, by the mean of annealing protocols prior delivery the material to end user. But duration of such a step is usually overestimated and even sometimes not necessary. In addition, this is time and energy consuming but still minimal one remains often necessary in the attempt to erase any prior thermal history. These protocols are usually predefined using standard tool i.e. differential calorimetry (DSC) but do not evidence the precise phase content or distribution. It is also usually observed the interdependence of a structure present at the atomic scale (crystalline phase) and at the mesoscale (i.e. lamellar, hexagonal…) but the related signature in the DSC remains imprecise with this respect. It is therefore of particular interest to perform a simultaneous investigation of the structures present, both at the atomic and mesoscopic scale. Simultaneous data collection is here of particular interest since both scales will be probed in the course of the thermal treatment, enabling to reveal crystalline phase and morphology without ambiguity.<br/>Small Angle X-Ray Scattering (SAXS) is a technique well suited for investigating nano-materials and nano-structures of polymers. The technique gives information on sample structure parameters such as particle shape or size, size distribution, orientation, surface to volume ratio,… in the range from 1 nm to beyond 100 nm. In combination with Wide Angle X-ray Scattering (WAXS), the technique can provide information on length-scales down to 0.1 nm, thus allowing measuring both crystalline and nano-structure properties. In this paper, we will present recent results on the thermal behavior of polymeric films undergoing crystalline phase transformation during a thermal process immediately after film formation.

Simultaneous SAXS/WAXS investigation of out-of-equilibrium polymer films

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.