A Low-Cost Method to Prepare Biocompatible Filaments with Enhanced Physico-Mechanical Properties for FDM 3D Printing

Abstract

Background: Fused Deposition Modelling (FDM) 3D printing has received much interest as a fabrication method in the medical and pharmaceutical industry due to its accessibility and cost-effectiveness. A low-cost method to produce biocompatible and biodegradable filaments can improve the usability of FDM 3D printing for biomedical applications.

Objectives: The feasibility of producing low-cost filaments suitable for FDM 3D printing via single screw and twin-screw hot melt extrusion was explored.

Methods: A single-screw extruder and a twin-screw extruder were used to produce biocompatible filaments composed of varying concentrations of polyethylene glycol (PEG) at 10%, 20%, 30% w/w and polylactic acid (PLA) 90%, 80% and 70% w/w, respectively. DSC, TGA and FTIR were employed to investigate the effect of PEG on the PLA filaments.

Results: The presence of PEG lowered the processing temperature of the formulation compositions via melt-extrusion, making it suitable for pharmaceutical applications. The use of PEG can lower the melting point of the PLA polymer to 170°C, hence lowering the printing temperature. PEG can also improve the plasticity of the filaments, as the rupture strain of twin-screw extruded filaments increased up to 10-fold as compared to the commercial filaments. Advanced application of FTIR analysis confirmed the compatibility and miscibility of PEG with PLA.

Conclusion: Twin-screw extrusion is more effective in producing a polymeric mixture of filaments as the mixing is more homogenous. The PEG/PLA filament is suitable to be used in 3D printing of medical or pharmaceutical applications such as medical implants, drug delivery systems, or personalised tablets.

Keywords: Biocompatible; FDM 3D printing; biopolymers; filaments; hot melt extrusion; polyethylene glycol (PEG)..