ABSTRACT This study investigated the thermal and spectroscopic properties of composites produced from Polyamide 12 (PA 12) and montmorillonite (MMT) or sepiolite (SEP) clays, for application in additive manufacturing. These properties are critical during the printing process, as they directly affect the balance between the energy input to the parts and their resulting mechanical properties and surface quality. The polymer/clay mixtures were prepared using a twin‐screw extruder, with PA 12 sourced from recycled material obtained through the Multi Jet Fusion (MJF) AM process. The clay concentrations evaluated were 2%, 5%, and 8%. The thermal stability of PA 12 improved with the incorporation of clays, with the effect being more pronounced in compositions containing MMT. This enhancement is attributed to the superior barrier effect provided by the layered structure of MMT compared to SEP. Under the experimental conditions employed in differential scanning calorimetry (DSC), no significant changes were observed in the crystallization and melting behavior of PA 12 upon filler incorporation, even at higher loading levels. These results indicate that the presence of the filler did not markedly affect the thermal transitions of the material. However, the addition of filler may restrict polymer chain mobility, acting as a physical barrier that hinders structural rearrangements and potentially influences the dynamics of the crystallization process. FTIR‐ATR spectra confirmed the preservation of the characteristic peaks of PA 12 and revealed additional bands associated with the clay structure, evidencing interactions between the composite components.
Azevedo et al. (Fri,) studied this question.