Continuous emulsion copolymerization processes at mild conditions in a 3D-printed tubular bended reactor

Significance 

With the advancement in chemistry industry, it is more realized that the design and construction of individualized, configurable devices for the exploration of chemical production units could strongly benefit from the options of current 3D printing techniques. Generally, 3D printing has evolved and is continually finding increasing roles in scientific research contexts such as in chemical synthesis and chemical engineering. As such, an attempt has been made to employ 3D printing in the processes of continuous polymerizations. The most promising so far is in the fused deposition modelling 3D printers for the fabrication of reactors. They involve extrusion of thermoplastic material through a high temperature nozzle to build a 3D object layer-by-layer. Nonetheless, no work has been published to confirm such an enviable process nor its practicality in chemistry related developments.

University of Hamburg researchers demonstrated how the design, the 3D printing and the characteristics of the resulting tubular bended reactor, present a viable alternative for performing continuous emulsion polymerizations. Their work is currently published in Chemical Engineering Journal.

The research method employed commenced with the integration of a polylactic acid tubular bended reactor, printed by fused deposition modeling with a short and narrow residence time distribution, air-cooled, and with dead volumes below 5%, into a modular reaction system enabling product changes in the running system. Next, continuous, redox-initiated emulsion co-polymerizations of styrene – butyl acrylate and of vinyl acetate – neodecanoic acid vinyl ester were successfully performed with 20 and 40 wt% monomer in the feed.

The authors observed that the integration of the 3D-printed tubular bended reactor into the modular reaction plant allowed the reproducible preparation of uniform copolymer particles at various solid contents as well as polymer product changes in the same 3D printed reactor while running. In addition, they noted that no fouling, clogging or deformation of the 3D-printed reactor was observed. Moreover, the option of thermal imaging was seen to allow for visualization of the polymerization processes.

In a nutshell, the study presented a detailed demonstration of the viability and versatility, and indicated the configurability of 3D printing a tubular bended reactor for carrying out emulsion co-polymerizations. In general, the filament used for the fabrication of the device was inexpensive and provided a suitable inert material for the reactions performed. To sum it all, the robust and applicable tubular bended reactor was noted to have a short and narrow residence time distribution, small dead volumes and suitable flow characteristics for emulsion copolymerization processes. Altogether, the approach demonstrated here is as versatile as the software used for generating the reactor and limited only by the characteristic constraints of a 3D printer.

Continuous emulsion copolymerization processes at mild conditions in a 3D-printed tubular bended reactor - Advanced Engineering

About the author

Prof. Dr. Gerrit A Luinstra holds a Ph.D. in chemistry, awarded by the “Rijksuniver-siteit Groningen” (1991, Netherlands) for a thesis entitled “investigations in organo-titanium chemistry” (Promotor was Prof. Teuben). He was member of Prof. Bercaw’s group at the Caltech from 1991-3, performing research on the catalytic oxidation of hydrocarbons in water. He habilitated in 2000 (“Universität Konstanz” with Prof. Brintzinger), also doing research on metal catalyzed polymerizations. During this period he joined the BASF SE in Ludwigshafen (a. Rh.) in the polymer research laboratories, where he remained until early 2008, when he was appointed to full Professor in Macromolecular Chemistry at the “Universität Hamburg”.

His research now is directed by the objective to link, simplify and advance scientific principles to the level of “barrier-free” industrial application. The activities comprise the development of (polymerization) catalysts, preparation of monomers, performing polymerizations & post-synthesis polymer functionalization, process predevelopment (scale up) and elementary polymer processing. The pyrolysis of plastic waste (and of general kerogens) along the “Hamburger Verfahren” is also part of the research.

About the author

Prof. Dr. Hans-Ulrich Moritz is a chemist and full Professor of the University of Hamburg and holder of the chair of Technical Macromolecular Chemistry of the Uni-versity Institute for Technical and Macromolecular Chemistry. He was born in West-Berlin on June 30th, 1952. His scientific life started in the research group of Prof. Dr. Karl-Heinz Reichert with a PhD thesis on: “Continuous bead polymerization of vinyl acetate in a stirred tubular reactor” and is since then focused on polymer reaction engineering. Consequently, he defended a postdoctoral thesis on “Computer-assisted laboratory reactor for emulsion polymerization of vinyl acetate” in 1988.

After a short industrial intermezzo, he got his first full professorship for Technical Chemistry and Chemical Process Engineering at the University of Paderborn in 1990. During his scientific career, he published numerous articles and is documented as inventor in many patents.

His research focus is polymer reaction engineering with a special focus on process safety and reactor design.

About the author

Dr. Werner Pauer studied chemistry at the Dresden University of Technology and obtained his Diploma (1992) in technical chemistry under supervision of Prof. Win-fried Pippel. He then joined the group of Prof. Hans-Ulrich Moritz at Paderborn Uni-versity for a PhD project. He worked on reactor concepts for suspension polymeriza-tion and obtained his PhD degree in 1996. Since 1996 he is a research fellow at Hamburg University.

His current research focus is polymer reaction engineering with a special focus on polymerization in dispersed phase and questions of mass transfer. Hence 3D printed reaction ware is investigated with respect to process intensification.

About the author

Sven Bettermann received his B.Sc. and M.Sc. degree in Chemistry from the University of Hamburg, Germany. During this time, he was a scholar and research assistant at University of Lisbon, Portugal in the framework of a six-month research project funded by the German Academic Exchange Service (DAAD). He further became a member of the BASF European Talent Pool as well as the Grow Together loyalty program and thus worked for six months at the Innovation Campus Asia Pacific in Shanghai, China.

Currently, he is a Ph.D. candidate and research associate at the Institute for Tech-nical and Macromolecular Chemistry in Hamburg, Germany. Sven is a member of the MIN Graduate School International and obtained a Scientific Management Scholarship as well as a Ph.D. Fellowship. He was further a visiting researcher at the Singapore Centre for 3D Printing (SC3DP) at the Nanyang Technological University in Singapore. His research interests focus on Chemical and Manufacturing Engineering comprising the application of 3D-printed reactors and reactionware in the development and intensification of chemical processes.

About the author

Baldur Schroeter studied chemistry at the University of Hamburg, and received his Diploma (06/2014) in chemistry under supervision of Prof. Hans-Ulrich Moritz at the Institute for Technical and Macromolecular Chemistry (Hamburg), subsequently fol-lowed by a PhD project in the same working group.

The research focus of the project was on the kinetics of flexible redox initiator systems, inline analytic methods and emulsion polymerization with a special focus on fast polymerizations at low temperatures. During this time he was also a visiting re-searcher at the Wacker Chemie AG in Burghausen in the framework of an industrial placement. He obtained his PhD degree in 10/2018.

His research interests focus on the optimization of polymerization kinetics for various processes, e.g. continuous polymerization in 3D-printed reaction ware, micro reactors and spray processes, with respect to process intensification as well as the adjustment of product properties.

About the author

Marcel Fassbender graduated from the University of Hamburg, Germany with a de-gree in chemistry and received his diploma in 2016. During his time as a student, he completed a six-month lab in-ternship at the group of David S. Larsen at the University of Otago, New Zealand. He was entrusted with the work of researching a new synthetic route to synthesize mannose-α-6-mannose glycoclus-ter.

He is currently a Ph.D. candidate in the group of G. A. Luinstra at the Institute for Technical and Macromolecular Chemistry in Hamburg, Germany. Marcel is currently working on basic concepts for using static mixers in additively manufactured tube reactors for continuous chemical reactions. He also deals with the concept of smart reactors. Here, measuring sensors are integrated directly via the additive manufacturing process without invasive intervention after production.

Reference

Sven Bettermann, Baldur Schroeter, Hans-Ulrich Moritz, Werner Pauer, Marcel Fassbender, Gerrit A. Luinstra. Continuous emulsion copolymerization processes at mild conditions in a 3D-printed tubular bended reactor. Chemical Engineering Journal 338 (2018) 311–322.

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