PHB nanostructured: Production and characterization by NMR relaxometry

Nanostructured materials based on PHB and different types of nanoclay were prepared and characterized as regards changes in the thermal behavior and morphological/structural characteristics. With respect to the thermal degradation profile, the addition of nanoclays to the PHB matrix did not, in general, cause loss of thermal stability. Regarding morphology/structure, X-ray diffraction revealed that the addition of the nanonoclays altered the crystallinity profile of some samples and suggested that the materials containing 1 wt% nanoclay have a predominantly exfoliated structure. In turn, the information obtained by NMR relaxometry provided a more precise and detailed understanding of the nanomaterials' structure, including the systems with 1 wt% nanoclay. The T1H values provided details on the degree of intercalation/exfoliation attained by the different systems, and the domain distribution curves allowed insight into the homogeneity of the systems. According to the NMR relaxometry data, the system formed by PHB/S7 presented the best exfoliated/intercalated relation.