Poly(ether ester) Ionomers as Water-Soluble Polymers for Material Extrusion Additive Manufacturing Processes.
Water-soluble polymers as sacrificial supports for additive manufacturing (AM) facilitate complex features in printed objects. Few water-soluble polymers beyond poly(vinyl alcohol) enable material extrusion AM. In this work, charged poly(ether ester)s with tailored rheological and mechanical properties serve as novel materials for extrusion-based AM at low temperatures. Melt transesterification of poly(ethylene glycol) (PEG, 8k) and dimethyl 5-sulfoisophthalate afforded poly(ether ester)s of sufficient molecular weight to impart mechanical integrity. Quantitative ion exchange provided a library of poly(ether ester)s with varying counterions, including both monovalent and divalent cations. Dynamic mechanical and tensile analysis revealed an insignificant difference in mechanical properties for these polymers below the melting temperature, suggesting an insignificant change in final part properties. Rheological analysis, however, revealed the advantageous effect of divalent countercations (Ca2+, Mg2+, and Zn2+) in the melt state and exhibited an increase in viscosity of two orders of magnitude. Furthermore, time-temperature superposition identified an elevation in modulus, melt viscosity, and flow activation energy, suggesting intramolecular interactions between polymer chains and a higher apparent molecular weight. In particular, extrusion of poly(PEG8k-co-CaSIP) revealed vast opportunities for extrusion AM of well-defined parts. The unique melt rheological properties highlighted these poly(ether ester) ionomers as ideal candidates for low-temperature material extrusion additive manufacturing of water-soluble parts.
School of Biomedical Engineering and Sciences, Virginia Tech , Blacksburg, Virginia 24061, United States.
Allison M
AM
Pekkanen
Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
Callie
C
Zawaski
Department of Materials Science and Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
André T
AT
Stevenson
Department of Chemical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
Ross
R
Dickerman
School of Biomedical Engineering and Sciences, Virginia Tech , Blacksburg, Virginia 24061, United States.|Department of Materials Science and Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.|Department of Chemical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
Abby R
AR
Whittington
Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
Christopher B
CB
Williams
Timothy E
http://orcid.org/0000-0001-9515-5491
TE
Long
additive manufacturing; counterion; ionomers; material extrusion; poly(ethylene glycol)