The elimination of plastics is inconceivable in the modern world. Unfortunately, they do have disadvantages, including the depletion of fossil feedstocks, formation of CO2 in production and combustion, and growth of landfills.
In the Angewandte Chemie journal, Russian scientists introduce a new method, where a polymer produced entirely from biomass can easily and economically be used in 3D printing. Objects produced through this method are of highly solvent-resistant, easily recyclable, and high quality.
Standard “subtractive” processes involve sawing, turning, cutting, or milling, lead to a great amount of wasted material. 3D printing processes are theoretically waste-free because they are “additive”: three-dimensional objects are generated in a layer-by-layer application of material. The most common method is called fused deposition modeling (FDM). In this method, the raw material is squeezed through a hot nozzle onto a mobile base and thus liquefied (extrusion). The printer head generates the programmed form like in a traditional two-dimensional printing technique, releasing small amounts of the polymer in place of ink. This process is repeated for layer after layer until achieving the required three-dimensional object. Yet, the polymers employed until now have several disadvantages that restrict their use. Some of the polymers are damaged by organic solvents. On the other hand, those that withstand the solvents adhere poorly and shrink on heating, enabling their layers to separate and making errors in the printing process.
Working along with Valentine P. Ananikov at the Russian Academy of Sciences (Moscow), researchers have now solved these problems by developing a sustainable technique: 3D printing with polyethylene-2,5-furandicarboxylate (PEF), a polymer made from cellulose.
The research team was able to successfully make objects by using a commercially obtainable 3D printer under standard settings. The printed objects’ individual layers were strongly bound to each other and the surface was of high quality and smooth. Tests showed that the objects were resistant to dichloromethane, which is one of the most aggressive solvents known. Thanks to the extreme thermal stability of the PEF, the printed objects can be continually melted, formed into filaments, and printed again.
Computer calculations show that the individual building blocks of PEF can include non-linear fragments and develop a spiral twist, which provides an access to new kinds of geometry. Another vital feature is a greater polarity of PEF. According to researchers, structural diversity can open new superior applications of PEF.