TEM morphological analysis of biopolymers: The case of Poly (Lactic Acid) (PLA)

Transmission Electron Microscopy (TEM) is one of several techniques for studying the morphology of polymers, which allows the analysis of their micro- and nano-domains, providing essential insights into their fundamental properties. To achieve such information, this paper proposes an extensive TEM characterisation of a crystalline Poly (Lactic Acid) (PLA), one of the first fully biobased and biodegradable polymers able to compete with traditional polymers in terms of performance. Further, the investigated biopolymer will be manufactured by injection moulding, one of the main industrial processing techniques in the field of biopolymer production. To improve TEM imaging, the best staining/coating conditions of PLA thin sections will be determined. Then, it will be described the arrangements of spherulites in PLA, as well as their lamellar organization within, by exploiting different sample sectioning approaches (i.e., directional and serial).