Digital Light Processing Route for 3D Printing of Acrylate-Modified PLA/Lignin Blends: Microstructure and Mechanical...

Area of Science:

• Materials Science
• Polymer Chemistry
• Additive Manufacturing

Background:

• Developing sustainable and cost-effective materials for 3D printing is crucial.
• Polylactic acid (PLA) is a widely used biodegradable polymer, but its properties can be enhanced.
• Lignin, a byproduct of the paper industry, is an abundant, renewable aromatic polymer with potential as a filler.

Purpose of the Study:

• To investigate the feasibility of creating 3D-printed blends using acrylate-modified polylactic acid (PLA) and softwood lignin.
• To analyze the effect of varying lignin content (5-30 wt%) on the microstructure and tensile mechanical properties of DLP-printed composites.
• To evaluate the influence of post-curing treatment on the performance of these bio-sourced 3D-printed materials.

Main Methods:

• Digital Light Processing (DLP) 3D printing was used to fabricate PLA-lignin composite blends.
• X-ray microtomography was employed to examine the microstructure of the printed samples.
• Tensile mechanical properties were assessed, considering lignin weight ratio and post-curing.

Main Results:

• Post-curing significantly enhanced the tensile properties of the 3D-printed composites, notably reducing brittleness.
• An optimal lignin content of approximately 5 wt% was identified for effective UV light photopolymerization.
• Higher lignin concentrations (beyond 5 wt%) negatively impacted the photopolymerization process.

Conclusions:

• Acrylate-modified PLA/lignin blends are a viable, cost-effective option for producing 3D-printed bio-sourced components.
• These materials offer a sustainable alternative with maintained technical performance for low-temperature 3D printing.
• The study highlights the importance of lignin content optimization and post-curing for achieving desired material properties.