An Exploratory Study on the Development of Algae-Based Biodegradable Polymer Composite Structures Via Selective Laser Sintering

Abstract

In response to climate change and agricultural runoff affecting the Amazon River, significant accumulations of brown macroalgae, Sargassum, have been observed along the South Coast of North America and the Caribbean since 2011. This has led to adverse effects on marine ecosystems, human health, and coastal economies. Despite these drawbacks, Sargassum presents potential applications in industries like cosmetics, fertilizers, and construction materials. However, its potential as a biomaterial for additive manufacturing (AM), specifically selective laser sintering (SLS) 3D printing, remains largely unexplored. The primary objective of a recent research project was to investigate the use of Sargassum/biopolymer composite micro-powders for SLS 3D printing, aiming to diversify the materials compatible with SLS, which is currently dominated by polyamide 12 (PA12).

The research achieved the following: (1) fabrication of biopolymer/Sargassum composite micro-powders with 30 wt% algal biomass content and excellent flow ability or SLS, (2) production of biopolymer/Sargassum composite specimens through SLS, and(3) characterization of powder flowability, comparing it to PA12. The fabrication process involved wet granulation, including pulverizing dried Sargassum, incorporating it into an aqueous biopolymer/binder dispersion, drying the resulting paste, and granulating the dried cake into fine powders. The powders were then characterized via optical microscopy using ImageJ software, and flowability measurements like angle of repose, Carr’s compressibility index (CI), and Hausner Ratio (HR). To fabricate the 3D printed specimens, the powders are fed into a SLS machine from Sintratec®, where the printing process takes place under controlled conditions.

The study found that the PHBV/sargassum powder feedstock initially exhibited poor flowability, causing printing problems and brittle specimens. Granulating the powder improved flowability, reduced printability issues, and decreased superficial defects in the specimens. However, the specimens remained somewhat brittle. The particle size distribution (PSD) for PHBV/sargassum granulated varied widely, emphasizing the need to optimize particle size and distribution for successful sintering. Despite challenges, the modified granulation protocol proved successful in enhancing flow ability and spreadability, offering a simple and cost-effective method for granulating powder feedstock for SLS.