No Such Thing as Trash: A 3D-Printable Polymer Composite Composed of Oil-Extracted Spent Coffee Grounds and Polylactic Acid with Enhanced Impact Toughness

Abstract

As one of the most popular beverages in the world, a large amount of coffee wastes known as the spent coffee grounds (SCGs) is generated daily. In this study, we report a polylactic acid (PLA) composite filament with a high loading of oil-extracted spent coffee grounds (Ox-SCGs) up to 20% by weight and is three-dimensional (3D)-printable with a commercially available consumer-level 3D printer. The Ox-SCG-loaded PLA was found to be able to increase impact energy absorption. As a result, the PLA/Ox-SCG composite exhibited a 418.7% increase in toughness with a measure of 25.24 MJ/m3 at a 20 wt % Ox-SCG loading and only a 26% storage modulus reduction from the 100% PLA specimens at room temperature. The experimental results indicate that as a waste product from human consumptions and post biodiesel extraction, the Ox-SCG is proven to be a promising additive for composite property modification. The Ox-SCG can not only increase the impact toughness but also reduce the cost of overall 3D-printing materials.

Development of Injection-Molded Polylactide Pieces with High Toughness by the Addition of Lactic Acid Oligomer and Characterization of Their Shape Memory Behavior

“…Polylactide (PLA) is a linear thermoplastic biodegradable polyester that can be obtained from starch-rich materials by fermentation to give lactide, which is polymerized at the industrial scale by ring-opening polymerization (ROP) [1]. PLA is a sound candidate to substitute some plastic commodities such as polypropylene (PP) or polystyrene (PS) in packaging applications [2][3][4][5][6], electronics [7], automotive [8], agriculture [9], textile, consumer goods, 3D printing applications [10][11][12][13], biomedical devices [14,15], pharmaceutical carriers [16,17], etc. The main advantage of PLA over As PLA is very sensitive to moisture, the biopolyester pellets were dried at 60 • C for 24 h. The OLA content varied in the 0-20 wt% at weight steps of 5 wt%.…”

Smart polymers and nanocomposites for 3D and 4D printing

“…The filament should be developed of accurate contents and proper composition to give desirable rheological and mechanical properties. Providing a homogeneous dispersion of reinforcements and inhibiting from void formation during fabrication process of the filament are of the most significant challenges of FDM method [81]. Flowability of the melted composite filament also needs to be controlled through a proper selection of viscosity of the extruded material.…”

Predictive mechanics-based model for depth of cut (DOC) of waterjet in soft tissue for waterjet-assisted medical applications

“…where A b is the cross-sectional area of the bar and A 0 is the original area of the specimen [22], [13].…”

“…Table 1 Strain rates ("), and crack growth rates (ṙ) associated with waterjet diameters (D), and velocities (v) used in this paper. The values of this table are calculated using (11), and (13). In order to accurately validate the depth of cut model, the tissue properties should be measured at the strain rates, and crack growth rates related to waterjet penetration into soft tissue.…”

“…In which J IC is mode I fracture toughness ( J m 2 ) which is dependent on crack growth rate already developed in (13).…”