Structure-Processing-Property Relationships of 3D Printed Porous Polymeric Materials

Area of Science:

• Materials Science
• Polymer Science
• Additive Manufacturing

Background:

• 3D printed porous polymers offer lightweight, flexible, and customizable properties for applications like sensors and garments.
• Existing methods for creating porosity in 3D prints have limited exploration of structure-processing-property relationships.

Purpose of the Study:

• To develop and characterize 3D printed porous polymeric materials with tunable porosity and mechanical properties.
• To investigate the relationship between processing parameters, resulting porous structure, and material performance.

Main Methods:

• Direct ink writing (DIW) of photopolymer/sacrificial paraffin composite inks.
• Paraffin removal via solvent immersion to create porous structures.
• Rheometry, scanning electron microscopy (SEM), tensile testing, and finite element analysis (FEA) for characterization and simulation.

Main Results:

• Successful 3D printing of composites with 40-70 wt% paraffin, yielding 43-73 vol% porosity.
• Transition from closed-cell to open-cell structures observed around 53 vol% porosity.
• Decreased elastic modulus with increased porosity; FEA confirmed Neo-Hookean and Ogden models' suitability for predicting mechanical behavior.

Conclusions:

• The DIW technique with sacrificial paraffin enables precise control over porous polymer structure and mechanical properties.
• The study establishes a framework combining rheometry, FEA, and DIW for designing tailored 3D printed porous materials.
• This approach facilitates the creation of advanced materials for specialized applications.