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Integration of Recycled Thermosets into Reconstituted Porous Scaffolds using Direct Writing with Pickering Foam Inks
Zekun Sun1, Yuanjun Xie1, Shukai Sun1
1College of Materials, MOE Key Laboratory of High-Performance Ceramic Fibers, Fujian Key Laboratory of Advanced Materials, Xiamen University, Xiamen, P. R. China.
Macromolecular Rapid Communications
|December 21, 2025
Summary
This study presents a green strategy for physically recycling polyurethane (PU) using 3D printing and Pickering foam ink. This method creates robust, hierarchical porous structures from recycled PU, adding value to thermoset recycling.
Area of Science:
- Materials Science
- Sustainable Chemistry
- Polymer Science
Background:
- Improving the recyclability of thermosets like polyurethane (PU) is crucial for sustainable innovation.
- Physical recycling offers scalability and energy efficiency over chemical recycling but often results in limited added value due to poor structural control.
- Existing physical recycling methods for PU struggle to impart structural regulation, hindering the creation of high-value materials.
Purpose of the Study:
- To demonstrate the feasibility of physically recycling polyurethane (PU) by incorporating recycled PU particles into a Pickering foam ink for 3D printing.
- To develop a sustainable method for creating reconstituted thermoset materials with controlled hierarchical porous structures and enhanced properties.
- To establish a green strategy for adding value to recycled thermosets through advanced manufacturing techniques.
Main Methods:
- Development of a waterborne PU and hydrophobic CaCO3 nanoparticle-based Pickering foam ink.
- Formulation of a shear-thinning ink by incorporating recycled PU particles into the Pickering foam.
- Direct ink writing (DIW) 3D printing of the reconstituted PU composite foam under ambient conditions.
- Characterization of the porous structure and mechanical properties of the 3D-printed scaffolds.
Main Results:
- Successful formulation of a stable Pickering foam ink suitable for direct ink writing.
- Creation of 3D-printed PU scaffolds with hierarchical porous structures using recycled PU particles.
- Demonstration that the Pickering foaming and DIW method enables structural regulation in recycled thermosets.
- The reconstituted composite foams exhibited robustness and added value compared to conventionally recycled PU.
Conclusions:
- Physical recycling of polyurethane (PU) is feasible through 3D printing with a Pickering foam ink, enabling structural control.
- This green strategy successfully merges recycled thermosets into reconstituted composite foams with hierarchical porous structures and robustness.
- The Pickering foaming and direct ink writing approach offers a promising, value-adding pathway for the sustainable physical recycling of thermosets.
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