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Rapid Carbanionic and Oxyanionic Polymerizations Transferred to Continuous Microfluidic Systems: Recent Results and Perspectives. Holger Frey Adrian Natalello, Jan Morsbach, Andreas Friedel, Christoph Tonhauser, Daniel Wilms. University of Mainz
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Rapid Carbanionic and Oxyanionic Polymerizations Transferred to Continuous Microfluidic Systems: Recent Results and Perspectives Holger Frey Adrian Natalello, Jan Morsbach, Andreas Friedel, Christoph Tonhauser, Daniel Wilms University of Mainz Institute of Organic and Macromolecular Chemistry Duesbergweg 10-14 55099 Mainz, Germany December 4, 2014, Paris
Polymerization „Reactors“ Hessel, V.; Serra, C.; Löwe, H.; Hadziioannou, G. Chem. Ing. Tech. 2005, 77, 1693.
Review Articles D. Wilms, J. Klos, H. Frey, Macromol. Chem. Phys.2008, 209(4), 343-356. C. Tonhauser, A. Natalello, H. Löwe, H. Frey, Macromolecules2012, 45, 9551-9570.
Outline • Carbanionic / Oxyanionic Polymerization in Continuous Flow • Living Carbanionic Polymerization: Introduction • Use of Micromixing Devices for Carbanionic Polymerization • End-Functional Polymers • Synthesis of Block Copolymers by Carbanionic Polymerization • Controlled Polydispersity via Microfluidic Strategies • Oxyanionic Polymerization in Microfluidic Devices • Conclusion and Perspectives
SIMM-V2 HP-IMM Living Carbanionic Polymerization • Characteristics: • Precise Control over Molecular Weight (via M/I), Low Polydispersity • Mostly Rapid Polymerization, even at Low Temperatures • Living Character Various Macromolecular Architectures • Inherently Sensitive to Impurities • Commonly Highly Exothermic Micromixer: Fast Mixing, Excellent Heat Dissipation, Continuous Problems: Mixing, Heat Dissipation, Sensitivity, Reaction Times ? Living Anions “on Tap“
Effective mixing • High surface-to-volume ratio • Small internal volume • High chemical and • mechanical resistance Polymerization in Continuous Flow Tonhauser, C.; Natalello, A.; Löwe, H.; Frey, H. Macromolecules. 2012, 45 (25), 9551–9570. Jähnisch, K.; Hessel, V.; Löwe, H.; Baerns, M. Angew. Chem. Int. Ed. 2004, 43, 406-446. Wilms, D.; Klos, J.; Frey, H. Macromol. Chem. Phys. 2008, 209, 343-356. Wurm, F.; Wilms, D.; Klos, J.; Löwe, H.; Frey, H. Macromol. Chem. Phys. 2008, 209, 1106-1114.
Slit Interdigital Micromixers: Laminar Mixing Multilamination Mixing Device
Living Anionic Polymerization of Styrene High Rate Constants (Dependent on Solvent, Temperature, Concentration) 1 .Solvent: Cyclohexane Non-Polar Reaction Medium Wurm, F.; Wilms, D.; Klos, J.; Löwe, H.; Frey, H. Macromol. Chem. Phys. 2008, 209, 1106
Carbanionic Polymerization in Non-Polar Medium • Narrow Molecular Weight Distribution • Convenient Adjustment of Molecular Weight at Varying Flow Rate Ratios SEC (THF) RI Detection Flow Rates: 1 – 3.5 mL/min Residence Times: 40 – 120 s
Carbanionic Polymerization in Non-Polar Medium • Full Conversion (NMR spectroscopy) • Quantitative Functionalization (MALDI-ToF-MS) MALDI-ToF MS 1H-NMR (CDCl3)
Carbanionic Polymerization in Polar Medium • Solvent: THF Polar Reaction Medium • Extremely Fast Kinetics; Control inConventional Set-Up Only Possible at Low Temperature • Fast Mixing and Excellent Heat Transfer in the Microstructured Reaction Device Permit Continuous Synthesis of Well-Defined Polystyrenes at 25°C
Polar Medium (THF): Room Temperature (!) Flow Rates: 0.8 – 2.6 mL/min Residence Times: 1.6 – 5.0 s SEC (THF) RI Detection
Conventional Approach vs. Micromixing Living Carbanionic Polymerization of Styrenic Monomers: Batch Reactor vs. Microstructured Reactor
Versatile Synthesis of End-Functional Polymers EEGE (Ethoxy Ethyl Glycidyl Ether) • Conventional Access to End-Functional Polymers via Carbanionic Polymerization • Termination Agents: Chlorosilane, Diphenylethlene (DPE) and Epoxides • Epoxide Derivatives Quantitative Functionalization (Quirk et al.) Quirk, R. et al. Macromol. Symp. 2000, 161, 37-44. Quirk, P. R.; Gomochak, D. L. Rubber Chem. Technol. 2003, 76, 812.
Synthesis of End-Functional Polystyrene End-Functionalization of Polystyrene in THF (Polar Medium) • Termination in Supplementary T-Junction • Continuous Flow Process: Polymerisation-Termination Sequence • Rapid and Quantitative Functionalization
Synthesis of End-Functional Polystyrene Flow Rates: 0.5 – 1.5 mL/min Residence Times: 5 – 15 s SEC (THF) RI Detection
Synthesis of End-Functional Polystyrene Flow Rates: 0.5 – 1.5 mL/min Residence Times: 5 – 15 s MALDI-ToF MS
Functional Termination C. Tonhauser, D. Wilms, F. Wurm, E. Berger-Nicoletti, M. Maskos, H. Löwe, H. Frey, Macromolecules2010, 43, 5582-5588
Synthesis of End-Functional Polystyrene • Release of Hydroxyl Groups by Acidic Hydrolysis • Semi-Continuous Approach to Hydroxy Functional Polymers Facile Access to Precursors for Complex Macromolecular Architectures (Blockcopolymers, Miktoarm Star Polymers)
Change Mixing Pattern: Turbulent Mixing 4-Way Jet Mixing Device Initiator Polymer Monomer
Polymerization in Continuous Flow Styrene in THF sec-BuLi in hexane 2-Vinyl pyridine in THF sec-BuLi in benzene
PS and P2VP Comparison Polymerization in Continuous Flow Natalello, A.; Morsbach, J.; Friedel, A.; Alkan, A.; Tonhauser, C.; Müller, A. H.E., Frey, H.; Org. Process Res. Develop., 2014, dx.doi.org/10.1021/op500149t
C. Serra et al., LAB ON A CHIP, 2008, 8,1682-1687 DOI: 10.1039/b803885f Influence of Mixing on Polydispersity
Control of Polydispersity by Microreactor Influence of PDI on polymer properties • Common mindset: “monodisperse polymers are good; polydisperse are bad”1 • Mainly theoretical investigations but only a few experimental contributions2 • Most experimental studies are based on mixing of several polymer samples3 Key issue: • No controllable parameter to tailor polydispersity is available • Lynd N A, Meuler A J, Hillmyer M A. Polydispersity and block copolymer self-assembly. Progress in Polymer Science 2008; 33; 875-893. • Leibler L. Theoryofmicrophaseseperation in block copolymers. Macromolecules 1980;13:1602-17. • (3)Noro A, Cho D, Takano A, Matsushita Y. Effectofmolecularweightdistribution on microphaseseperatedstructuresfrom block copolymers. Macromolecules 2005;38;4371-6.
Carbanionic polymerization Microreactor setup Pump 3: Termination reagent T M Pump 1: Monomer/Solvent Flow rate: x • Controlled living carbanionic polymerization • Well defined polymer architectures • Very narrow mass distributions possible (PDI < 1.10) • Linear dependence of the achieved molecular weights DP = [M]/[I] Mixer Mixing device I Pump 2: Initiator/Solvent Flow rate: y
Turbulent mixing device – point of broadening T M Mixer Flow rate/ ml min-1 I
Carbanions are still living: -> Quantitative functionalization (MALDI-ToF) total flow = 0.8 ml/min PDI (MALDI) = 1.10 T M total flow = 3.0 ml/min PDI (MALDI) = 1.09 Mixer I total flow = 4.0 ml/min PDI (MALDI) = 1.07 + 104 g/mol total flow = 6.0 ml/min PDI (MALDI) = 1.06 total flow = 10.0 ml/min PDI (MALDI) = 1.05
Summary T M • Systematic influence on the PDI of a polymerization at constant molecular weights achieved • System can be transferred to other polymer systems • Analysis how the properties are influenced are in progress • Quantitative functionalized polymers enables further investigations of block copolymer behavior Jan Morsbach PhD student Mixer I
Hyperbranched Polyglycerol: Target Mn = 1,000 g/mol SEC analysis (DMF) T = 120°C Continuous flow Throughput: 1 – 5 ml/min Reaction time: several minutes Mn ~ 750 g/mol Mw/Mn = 1.6 D. Wilms, J. Nieberle, J. Klos, H. Löwe, H. Frey, Chem. Eng.Technol.2007, 30(11), 1519-1524.
Hyperbranched Polyglycerol: Target Mn = 1,000 g/mol 1H-NMR analysis Repeat units Hydroxyl groups Initiator core Methanol-d4 Mn = 1,100 g/mol DPn= 16
Hyperbranched Polyglycerol: Initiator attachment? Confirmation of initiator core incorporation MALDI-ToF analysis Complete core incorporation (Independent of flow rates) 14
Hyperbranched Polyglycerol: Variation of Flow Rates SEC analysis (DMF) D. Wilms, J. Nieberle, J. Klos, H. Löwe, H. Frey, Chem. Eng.Technol.2007, 30(11), 1519-1524.
Hyperbranched Polyglycerol: Variation of Flow Rates SEC analysis (DMF) Mn ~ 150,000 g/mol Mw/Mn ~ 1.1 (PS Standards) Isolation by Dialysis 16
Conclusion & Perspectives • Polymer Synthesis in Microreactors: • Carbanionic and Oxyanionic Techniques • EfficientContinuous Flow Process for Living Carbanionic Polymerization • Facile and Fast Processes Serve to Optimize Reaction Parameters • Convenient Molecular Weight Adjustment • Tailoring of the Polydispersity of Living Polymer Cabanions • Quantitative Implementation of Various End-Groups at Polymers • FacileExtension to Complex Polymer Architectures • (Star Polymers, Block Copolymers)
Conclusion & Perspectives • PendingQuestions • Unprecedented Polymer Structures? • Kinetic Control ofPolymerizationofMetastable Monomers? • (Example: Vinyl Alcohol) • Gradients, One-Step Block CopolymerSyntheses, Architectures • by versatile multi-microfluidicsystems
Acknowledgments Prof. Holger Löwe Michael Maskos Elena Berger-Nicoletti Monika Schmelzer Institut für Mikrotechnik Mainz POLYMAT
Conclusion & Perspectives • PendingQuestions • Unprecedented Polymer Structures? • Kinetic Control ofPolymerizationofMetastable Monomers? • (Example: Vinyl Alcohol) • Gradients, One-Step Block CopolymerSyntheses, Architectures • by versatile multi-microfluidicsystems
Multilamination Flow Pattern Micromixer Inlay Mulitlamination Flow Pattern • Hydrodynamic Focusing • Jet Formation in the Slit-Shaped Interdigital Micromixer Method of Operation Hessel, V. et al.AIChE Journal 2003, 49, (3), 566-577. Löb, P. et al.Chemical Engineering Science 2006, 61, (9), 2959-2967.