7 research outputs found
Biobased Photopolymer Resin for 3D Printing Containing Dynamic Imine Bonds for Fast Reprocessability
Acrylic photopolymer resins are widely used in stereolithographic 3D printing. However, the growing demand for such thermosetting resins is weighing on global issues such as waste management and fossil fuel consumption. Therefore, there is an increasing demand for reactive components that are biobased and enable recyclability of the resulting thermoset products. In this work, the synthesis of a photo-cross-linkable molecule containing dynamic imine bonds based on biobased vanillin and dimer fatty diamine is described. Using the biobased building blocks, formulations containing reactive diluent and a photoinitiator were prepared. The mixtures could be rapidly cross-linked under UV light, yielding vitrimers. Using digital light processing, 3D-printed parts were prepared, which were rigid, thermally stable, and reprocessed within 5 min at elevated temperature and pressure. The addition of a building block containing a higher concentration of imine bonds accelerated the stress relaxation and improved the mechanical rigidity of the vitrimers. This work will contribute to the development of biobased and recyclable 3D-printed resins to facilitate the transition to a circular economy.</p
Die Europäische Zentralbank, die neue Institution in der Union und ihre geldpolitischen Funktionen
Hampering of the Stability of Gold Electrodes by Ferri-/Ferrocyanide Redox Couple Electrolytes during Electrochemical Impedance Spectroscopy
Stereolithographic 3D Printing with Renewable Acrylates
The accessibility of cost-competitive renewable materials and their application in additive manufacturing is essential for an efficient biobased economy. We demonstrate the rapid prototyping of sustainable resins using a stereolithographic 3D printer. Resin formulation takes place by straightforward mixing of biobased acrylate monomers and oligomers with a photoinitiatior and optical absorber. Resin viscosity is controlled by the monomer to oligomer ratio and is determined as a function of shear rate by a rheometer with parallel plate geometry. A stereolithographic apparatus charged with the biobased resins is employed to produce complex shaped prototypes with high accuracy. The products require a posttreatment, including alcohol rinsing and UV irradiation, to ensure complete curing. The high feature resolution and excellent surface finishing of the prototypes is revealed by scanning electron microscopy
Biobased Acrylate Photocurable Resin Formulation for Stereolithography 3D Printing
To facilitate the
ongoing transition toward a circular economy,
the availability of renewable materials for additive manufacturing
becomes increasingly important. Here, we report the successful fabrication
of complex shaped prototypes from biobased acrylate photopolymer resins,
employing a commercial stereolithography apparatus (SLA) 3D printer.
Four distinct resins with a biobased content ranging from 34 to 67%
have been developed. All formulations demonstrated adequate viscosity
and were readily polymerizable by the UV-laser-based SLA process.
Increasing the double-bond concentration within the resin results
in stiff and thermally resilient 3D printed products. High-viscosity
resins lead to high-resolution prototypes with a complex microarchitecture
and excellent surface finishing, comparable to commercial nonrenewable
resins. These advances can facilitate the wide application of biobased
resins for construction of new sustainable products via stereolithographic
3D printing methods