Poly(ether ester) Ionomers as Water-Soluble Polymers for Material Extrusion Additive Manufacturing Processes
Allison M Pekkanen1, Callie Zawaski2, André T Stevenson3
1School of Biomedical Engineering and Sciences, Virginia Tech , Blacksburg, Virginia 24061, United States.
ACS Applied Materials & Interfaces
|March 23, 2017
Summary
Novel water-soluble poly(ether ester) ionomers, utilizing poly(ethylene glycol) (PEG), enable low-temperature extrusion-based additive manufacturing (AM). Divalent cations significantly enhance melt viscosity, facilitating complex 3D printed parts with sacrificial support capabilities.
Area of Science:
- Polymer Science
- Materials Science
- Additive Manufacturing
Background:
- Water-soluble polymers are crucial sacrificial supports in additive manufacturing (AM) for creating intricate designs.
- Existing water-soluble polymers suitable for material extrusion AM are limited, with poly(vinyl alcohol) being a primary example.
Purpose of the Study:
- To develop novel charged poly(ether ester)s for low-temperature extrusion-based AM.
- To investigate the influence of counterions on the rheological and mechanical properties of these polymers for AM applications.
Main Methods:
- Synthesis of poly(ether ester)s via melt transesterification of poly(ethylene glycol) (PEG) and dimethyl 5-sulfoisophthalate.
- Modification of polymers through quantitative ion exchange to introduce various monovalent and divalent counterions.
- Characterization using dynamic mechanical analysis, tensile testing, rheological analysis, and time-temperature superposition.
Main Results:
- Poly(ether ester)s exhibited sufficient molecular weight and mechanical integrity below their melting temperature.
- Divalent countercations (Ca2+, Mg2+, Zn2+) dramatically increased melt viscosity by two orders of magnitude.
- Time-temperature superposition indicated enhanced modulus, melt viscosity, and flow activation energy with divalent cations, suggesting increased apparent molecular weight.
Conclusions:
- Charged poly(ether ester) ionomers are promising materials for low-temperature extrusion additive manufacturing.
- The tunable rheological properties, particularly the enhanced melt viscosity with divalent cations, are ideal for creating well-defined, water-soluble 3D printed parts.
- These materials offer new possibilities for complex feature fabrication in sacrificial support applications.
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