2024 AIChE Annual Meeting
From Brown Tides to 3D Printers: Fabrication & Characterization of Novel Sargassum-Based Polymer Composite Filaments for 3D Printing
As a direct effect of ocean warming and nutrient enrichment, tons of a brown macroalgae known as sargassum have been accumulating on the shores of the Caribbean region since 2011. These unprecedented annual events have been detrimental not only to some marine ecosystems but also to human health and the economy of several coastal communities. Despite the negative impact of the brown tide described above, sargassum has the potential to be a valuable resource for multiple industries, including pharmaceuticals, cosmetics, fertilizers, civil construction materials, and bioplastics. This study aimed to explore the use of this seaweed as a raw material for the fabrication of renewable micro- and nanoparticles incorporated into polymer-based filaments for fused deposition modeling (FDM) 3D printing. Specifically, the study sought to establish the process conditions for fabricating sargassum powder and polylactic acid (PLA)/sargassum composite filaments, study the effects of powder particle size and weight percentage on the microstructure, mechanical properties, thermal stability, and 3D printability of the fabricated filaments, examine the relationship between printing conditions, microstructure, and mechanical properties of the 3D printed specimens, and finally, study the biodegradability of these novel sargassum-based 3D printing materials.
In the procedure, dried sargassum previously collected from local beaches was ground in a food processor to obtain microparticles. Subsequently, a portion of the resulting material was re-ground in a planetary ball mill to obtain nanoparticles. Next, PLA pellets were coated with suitable amounts of powder (0% - 35% by weight) through mechanical mixing using small amounts of a suitable solvent as glue. The coated pellets were then fed into an extruder to fabricate the filaments. The extrusion temperatures and spooling speed were controlled to obtain the required filament thickness and quality. The sargassum-based filaments were placed in an FDM 3D printer to fabricate various dog-bone-shaped specimens and consumer products such as cell phone cases, earbud holders, and eyeglass frames.
The obtained powders were analyzed using AFM, SEM, FTIR, and Raman spectroscopy. The microstructure, thermal stability, and mechanical properties of the filaments and specimens were evaluated using SEM, TGA, and tensile tests, respectively. Preliminary biodegradability studies were conducted through soil burial tests.
The intellectual merit of this work lies in the fact that, for the first time, macroalgae powders were used in FDM 3D printing, offering alternatives to improve sustainability in 3D printing and addressing issues such as macroalgae proliferation.