restricts PLA chain mobility, increasing Tg and reducing Tm and Xc, whereas Organo Chocolate clay acts as a nucleation agent, increasing Tm and Xc, with amorphous chains having greater mobility due to distance from clay particles. Figure 7 - DSC curves of PLA organoclay samples: (a) Casting, (b) Extrusion. 1- PLA; 2- PLA/Organo Bofe clay and 3- PLA/Organo Chocoloate clay. 3.4 MEV/EDS 3.4.1 Morphology of bentonite samples The SEM images of natural and organo bentonites are presented in Figure 8, providing insight into their surface morphology and microstructure. Natural bentonites exhibit an aggregated morphology with a homogeneous particle size distribution, featuring small flakes approximately 2.0 µm in size, and a layered structure. In contrast, the organo bentonites display an expanded structure due to CTAB intercalation, appearing swollen with a multilayered shape and varying particle sizes (2-7 µm in diameter). The CTAB intercalation increases the basal spacing and reduces the attraction between adjacent lamellas, leading to a more open structure. Notably, some large flakes are observed in certain instances. Figure 8 - SEM-BSE electron images for natural and organo clays: (a) Natural Bofe clay; (b) Natural Chocolate clay; (c) Organo Bofe clay and (d) Organo Chocolate clay. 3.4.2 Morphology of PLA biocomposites SEM images of cryo-fractured surfaces (Figure 9) show a smooth matrix and good adhesion in PLA/organoclay biocomposites, indicating well-distributed organoclays. Extruded sheets exhibit heterogeneity and roughness, but no micropores or cracks are observed. High temperature, mechanical shearing, and interactions with plasticizers likely contribute to this morphology, enhancing mechanical and barrier properties.
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