Ceramic-reinforced polylactic acid composites for 3D-printed desiccant applications: Functional and mechanical performance

This work investigates two polylactic acid (PLA) filaments—reinforced with 20 wt% silica (PLA/Si) and alumina
(PLA/Al)—processed via material extrusion additive manufacturing without post-processing. The study aims to
assess their suitability for desiccant applications requiring both moisture sorption and mechanical stability under
cyclic humid and thermal conditions.
Morphological, chemical, and thermal analyses showed that incorporating ceramic fillers significantly
increased the surface area, porosity, and crystallinity of the filaments compared to pure PLA. Thermal stability
was enhanced without altering the glass transition or melting temperatures. Both composites exhibited a slight
reduction in mechanical properties compared with pure PLA. PLA/Si showed the greatest enhancement in
adsorption capacity, whereas PLA/Al also surpassed neat PLA in adsorption performance, though to a lesser
extent than PLA/Si, while incurring a smaller loss in mechanical strength. These outcomes highlight two
alternative material solutions, each offering a distinct balance between adsorption efficiency and mechanical
integrity, depending on the application requirements.
Under continuous humidity exposure, early hydrolytic degradation was observed, particularly in PLA/Si.
However, cyclic humidification combined with thermal regeneration preserved the mechanical integrity of both
composites. These results demonstrate the potential of PLA/Si and PLA/Al as recyclable, 3D-printable materials
for advanced desiccant applications.