A facile and green method to prepare highly luminescent and mechanically robust polylactide-based composites for three-dimensional printing

Polylactide (PLA), a bio-based polymer that is usually derived from renewable crops (e.g., corn and rice), is widely used in three-dimensional (3D) printing. New functional materials based on PLA for 3D printing are highly desirable; however, the traditional routes for preparing functional printable materials were either time-consuming or environmentally unfriendly. Here, we demonstrate for the first time a simple and environmentally friendly method to homogenously disperse functional filler within PLA matrix, by which mechanically robust and highly luminescent SrAl2O4:Eu2+, Dy3+ (SAO)/PLA composite filaments for 3D printing were readily achieved. This method involves the incorporation of only 1% of glycerol (based on the weight of PLA) as a dispersion agent and compatibility agent between hydrophilic SAO and hydrophobic PLA. Consequently, the luminescence intensity of composites increased linearly with SAO content, while 5% of SAO could obtain the maximum strength (60.2 ± 4.9 MPa), 50% higher than that of pure PLA. Moreover, the green method can be used to prepare other kinds of composite functional filaments for 3D printing.