本研究將使用四正丁基氯化铵(tetrabutylammonium chloride, TBACl)以及乙二醇(ethylene glycol, EG)來配製與甲基丙烯酸甲酯(methyl methacrylate, MMA)相溶的深共熔溶劑(deep eutectic solvent, DES)，並探討其對可見光引發之可逆加成斷裂鏈轉移聚合(reversible addition – fragmentation chain transfer, RAFT)聚合的影響。首先以三硫碳酸鹽(trithiocarbonate)當作鏈轉移劑(chain transfer agent, CTA)，並在無絕氧的環境下，發現可見光引發RAFT聚合速率能在深共熔溶劑中有效地提升。此外，鏈轉移劑在深共熔溶劑中有較高的穩定度，使得反應更有效率地進行並保留了多數的RAFT基團。接著探討反應性較差的二硫代苯酸鹽(dithiobenzoate)，比起以二甲基亞碸(dimethyl sulfoxide, DMSO)當作溶劑，在深共熔溶劑中反應速率可提升4.5倍。此外，我們嘗試在反應中加入光催化劑，以進行光誘導電子轉移(photoelectron/energy transfer-RAFT, PET-RAFT)反應。黃色曙紅(Eosin Y)在深共熔溶劑中表現出良好的相容性，並進一步地提升RAFT聚合反應速率。由於光催化劑的存在，我們可直接使用自然的太陽光來引發，發現在深共熔溶劑中仍可以達到較高的轉化率。簡言之，深共熔溶劑使RAFT反應能夠不受氧氣影響地進行高效率的光引發聚合。

In this work, we used tetrabutylammonium chloride (TBACl) and ethylene glycol as a nonpolar deep eutectic solvent (DES) to demonstrate the effect of solvents on the photo-induced reversible addition-fragmentation chain transfer (RAFT) polymerization of different vinyl monomers, including methyl methacrylate, methyl acrylate, N,N-dimethylacrylamide, and styrene. We mostly used methyl methacrylate as the model compound to conduct photo-induced RAFT polymerization under an open-to-air environment. Firstly, we found that DESs can enhance the polymerization rate of photoiniferter by using trithiocarbonate (TTC) as chain transfer agent (CTA). Moreover, the stability of CTAs was significantly increased in DESs to facilitate the controlled reaction and preserve RAFT end groups. Besides TTCs, the reaction can also be initiated by less efficient CTAs such as dithiobenzoate. Surprisingly, the dithiobenzoate-based polymerization exhibits a 4.5-fold increase in the apparent polymerization rate constant compared to the reaction in dimethyl sulfoxide (DMSO). Furthermore, we surveyed the photoelectron/energy transfer (PET) RAFT polymerization, which is the indirect photo-activation by photocatalysts (PCs). Eosin Y (EY) was found to be compatible with DES, providing an even higher polymerization rate than the pohotoiniferter polymerization when dithiobenzoate was used. The PET-RAFT polymerization enables us to use a wide spectrum of light such as natural sunlight, to initiate the reaction. In short, DESs provide an effective and green media to facilitate photo-induced RAFT polymerization in an open-to-air environment.

1. Corrigan, N.; Jung, K.; Moad, G.; Hawker, C. J.; Matyjaszewski, K.; Boyer, C., Reversible-deactivation Radical Polymerization (Controlled/living Radical Polymerization): From Discovery to Materials Design and Applications. Progress in Polymer Science 2020, 111.
2. Nicolas, J.; Guillaneuf, Y.; Lefay, C.; Bertin, D.; Gigmes, D.; Charleux, B., Nitroxide-mediated Polymerization. Progress in Polymer Science 2013, 38 (1), 63-235.
3. Ran, J.; Wu, L.; Zhang, Z.; Xu, T., Atom Transfer Radical Polymerization (ATRP): A Versatile and Forceful Tool for Functional Membranes. Progress in Polymer Science 2014, 39 (1), 124-144.
4. John Chiefari, Y. K. B. C., Frances Ercole, Julia Krstina, Justine Jeffery, Tam P. T. Le, Roshan T. A. Mayadunne, Gordon F. Meijs, Catherine L. Moad, Graeme Moad, Ezio Rizzardo, and San H. Thang, Living Free-Radical Polymerization by Reversible Addition-Fragmentation Chain Transfer: The RAFT Process. Macromolecules 1998, 31, 5559-5562.
5. Moad, G.; Rizzardo, E.; Thang, S. H., Living Radical Polymerization by the RAFT Process – A Third Update. Australian Journal of Chemistry 2012, 65 (8).
6. Perrier, S., 50th Anniversary Perspective: RAFT Polymerization—A User Guide. Macromolecules 2017, 50 (19), 7433-7447.
7. Houshyar, S.; Keddie, D. J.; Moad, G.; Mulder, R. J.; Saubern, S.; Tsanaktsidis, J., The Scope for Synthesis of Macro-RAFT Agents by Sequential Insertion of Single Monomer Units. Polymer Chemistry 2012, 3 (7).
8. Olson, R. A.; Levi, J. S.; Scheutz, G. M.; Lessard, J. J.; Figg, C. A.; Kamat, M. N.; Basso, K. B.; Sumerlin, B. S., Macromolecular Photocatalyst for Synthesis and Purification of Protein–Polymer Conjugates. Macromolecules 2021, 54 (10), 4880-4888.
9. Sun, Z.; Wang, M.; Li, Z.; Choi, B.; Mulder, R. J.; Feng, A.; Moad, G.; Thang, S. H., Versatile Approach for Preparing PVC-Based Mikto-Arm Star Additives Based on RAFT Polymerization. Macromolecules 2020, 53 (11), 4465-4479.
10. Cho, H. Y.; Krys, P.; Szcześniak, K.; Schroeder, H.; Park, S.; Jurga, S.; Buback, M.; Matyjaszewski, K., Synthesis of Poly(OEOMA) Using Macromonomers via “Grafting-Through” ATRP. Macromolecules 2015, 48 (18), 6385-6395.
11. Motokawa, R.; Iida, Y.; Zhao, Y.; Hashimoto, T.; Koizumi, S., Living Polymerization Induced Macro- and Microdomain Investigated by Focusing Ultra-small-angle Neutron Scattering. Polymer Journal 2007, 39 (12), 1312-1318.
12. Charleux, B.; Delaittre, G.; Rieger, J.; D’Agosto, F., Polymerization-Induced Self-Assembly: From Soluble Macromolecules to Block Copolymer Nano-Objects in One Step. Macromolecules 2012, 45 (17), 6753-6765.
13. Liu, C.; Hong, C.-Y.; Pan, C.-Y., Polymerization Techniques in Polymerization-induced Self-assembly (PISA). Polymer Chemistry 2020, 11 (22), 3673-3689.
14. Moad, G.; Rizzardo, E.; Thang, S. H., RAFT Polymerization and Some of Its Applications. Chemistry-An Asian Journal 2013, 8 (8), 1634-44.
15. Keddie, D. J.; Moad, G.; Rizzardo, E.; Thang, S. H., RAFT Agent Design and Synthesis. Macromolecules 2012, 45 (13), 5321-5342.
16. Yeow, J.; Chapman, R.; Xu, J.; Boyer, C., Oxygen Tolerant Photopolymerization for Ultralow Volumes. Polymer Chemistry 2017, 8 (34), 5012-5022.
17. Martin, L.; Gody, G.; Perrier, S., Preparation of Complex Multiblock Copolymers via Aqueous RAFT polymerization at Room Temperature. Polymer Chemistry 2015, 6 (27), 4875-4886.
18. Li, C.-Y.; Yu, S.-S., Efficient Visible-Light-Driven RAFT Polymerization Mediated by Deep Eutectic Solvents under an Open-to-Air Environment. Macromolecules 2021, 54 (21), 9825-9836.
19. Khan, M. Y.; Cho, M.-S.; Kwark, Y.-J., Dual Roles of a Xanthate as a Radical Source and Chain Transfer Agent in the Photoinitiated RAFT Polymerization of Vinyl Acetate. Macromolecules 2014, 47 (6), 1929-1934.
20. Xu, J.; Jung, K.; Atme, A.; Shanmugam, S.; Boyer, C., A Robust and Versatile Photoinduced Living Polymerization of Conjugated and Unconjugated Monomers and Its Oxygen Tolerance. Journal of the American Chemical Society 2014, 136 (14), 5508-19.
21. Shanmugam, S.; Xu, J.; Boyer, C., Exploiting Metalloporphyrins for Selective Living Radical Polymerization Tunable over Visible Wavelengths. Journal of the American Chemical Society 2015, 137 (28), 9174-85.
22. Nomeir, B.; Fabre, O.; Ferji, K., Effect of Tertiary Amines on the Photoinduced Electron Transfer-Reversible Addition–Fragmentation Chain Transfer (PET-RAFT) Polymerization. Macromolecules 2019, 52 (18), 6898-6903.
23. Xu, J.; Shanmugam, S.; Duong, H. T.; Boyer, C., Organo-photocatalysts for Photoinduced Electron Transfer-reversible Addition–fragmentation Chain Transfer (PET-RAFT) Polymerization. Polymer Chemistry 2015, 6 (31), 5615-5624.
24. Andrew P. Abbott, D. B., Glen Capper, David L. Davies, and Raymond K. Rasheed, Deep Eutectic Solvents Formed between Choline Chloride and Carboxylic Acids: Versatile Alternatives to Ionic Liquids. Journal of the American Chemical Society 2004, 126(29), 9142–9147
25. Smith, E. L.; Abbott, A. P.; Ryder, K. S., Deep Eutectic Solvents (DESs) and Their Applications. Chemical Reviews 2014, 114 (21), 11060-11082.
26. van Osch, D. J. G. P.; Zubeir, L. F.; van den Bruinhorst, A.; Rocha, M. A. A.; Kroon, M. C., Hydrophobic Deep Eutectic Solvents as Water-immiscible Extractants. Green Chemistry 2015, 17 (9), 4518-4521.
27. Singh, M. B.; Kumar, V. S.; Chaudhary, M.; Singh, P., A Mini Review on Synthesis, Properties and Applications of Deep Eutectic Solvents. Journal of the Indian Chemical Society 2021, 98 (11), 100210.
28. Mukhtar A. Kareem, F. S. M., Mohd Ali Hashim, and Inas M. AlNashef, Phosphonium-Based Ionic Liquids Analogues and Their Physical Properties. Journal of Chemical & Engineering Data 2010, 55 (11), 4632–4637.
29. Zhang, Q.; De Oliveira Vigier, K.; Royer, S.; Jerome, F., Deep Eutectic Solvents: Syntheses, Properties and Applications. Chemical Society Reviews 2012, 41 (21), 7108-7146.
30. Singha, N. K.; Pramanik, N. B.; Behera, P. K.; Chakrabarty, A.; Mays, J. W., Tailor-made Thermoreversible Functional Polymer via RAFT Polymerization in an Ionic Liquid: a Remarkably Fast Polymerization Process. Green Chemistry. 2016, 18 (22), 6115-6122.
31. Kubisa, P., Kinetics of Radical Polymerization in Ionic Liquids. Europen Polymer Journal. 2020, 133, 109778.
32. Thurecht, K. J.; Gooden, P. N.; Goel, S.; Tuck, C.; Licence, P.; Irvine, D. J., Free-Radical Polymerization in Ionic Liquids: The Case for a Protected Radical. Macromolecules 2008, 41 (8), 2814-2820.
33. Smith, E. L.; Abbott, A. P.; Ryder, K. S., Deep Eutectic Solvents (DESs) and Their Applications. Chemical Reviews. 2014, 114 (21), 11060-11082.
34. Santha Kumar, A. R. S.; Singha, N. K., RAFT Polymerization of 2‐Hydroxyethyl Methacrylate in a Deep Eutectic Solvent. Journal of Polymer Science Part A: Polymer Chemistry 2019, 57 (23), 2281-2286.
35. Quirós-Montes, L.; Carriedo, G. A.; García-Álvarez, J.; Presa Soto, A., Deep Eutectic Solvents for Cu-catalysed ARGET ATRP under an Air Atmosphere: a Sustainable and Efficient Route to Poly(methyl methacrylate) Using a Recyclable Cu(ii) Metal–Organic Framework. Green Chemistry 2019, 21 (21), 5865-5875.
36. Wang, J.; Han, J.; Khan, M. Y.; He, D.; Peng, H.; Chen, D.; Xie, X.; Xue, Z., Deep Eutectic Solvents for Green and Efficient Iron-mediated Ligand-free Atom Transfer Radical Polymerization. Polymer Chemistry 2017, 8 (10), 1616-1627.
37. An, Z., 100th Anniversary of Macromolecular Science Viewpoint: Achieving Ultrahigh Molecular Weights with Reversible Deactivation Radical Polymerization. ACS Macro Letters 2020, 9 (3), 350-357.
38. Carmean, R. N.; Becker, T. E.; Sims, M. B.; Sumerlin, B. S., Ultra-High Molecular Weights via Aqueous Reversible-Deactivation Radical Polymerization. Chemistry 2017, 2 (1), 93-101.
39. Gormley, A. J.; Yeow, J.; Ng, G.; Conway, O.; Boyer, C.; Chapman, R., An Oxygen-Tolerant PET-RAFT Polymerization for Screening Structure-Activity Relationships. Angewandte Chemie-International Edition 2018, 57 (6), 1557-1562.
40. Xie, W.; Zhao, L.; Wei, Y.; Yuan, J., Advances in Enzyme-Catalysis-Mediated RAFT Polymerization. Cell Reports Physical Science 2021, 2 (7), 100487.
41. Wang, M.; Zhang, J.; Guerrero-Sanchez, C.; Schubert, U. S.; Feng, A.; Thang, S. H., Enzyme Degassing for Oxygen-Sensitive Reactions in Open Vessels of an Automated Parallel Synthesizer: RAFT Polymerizations. ACS Combinatorial Science 2019, 21 (10), 643-649.
42. Zhang, B.; Wang, X.; Zhu, A.; Ma, K.; Lv, Y.; Wang, X.; An, Z., Enzyme-Initiated Reversible Addition–Fragmentation Chain Transfer Polymerization. Macromolecules 2015, 48 (21), 7792-7802.
43. Chapman, R.; Gormley, A. J.; Herpoldt, K.-L.; Stevens, M. M., Highly Controlled Open Vessel RAFT Polymerizations by Enzyme Degassing. Macromolecules 2014, 47 (24), 8541-8547.
44. Liu, Z.; Lv, Y.; An, Z., Enzymatic Cascade Catalysis for the Synthesis of Multiblock and Ultrahigh-Molecular-Weight Polymers with Oxygen Tolerance. Angewandte Chemie-Intternation Edition 2017, 56 (44), 13852-13856.
45. Li, R.; An, Z., Achieving Ultrahigh Molecular Weights with Diverse Architectures for Unconjugated Monomers through Oxygen-Tolerant Photoenzymatic RAFT Polymerization. Angewandte Chemie-Intternation Edition 2020, 59 (49), 22258-22264.
46. McKenzie, T. G.; Costa, L. P. d. M.; Fu, Q.; Dunstan, D. E.; Qiao, G. G., Investigation into the Photolytic Stability of RAFT Agents and the Implications for Photopolymerization Reactions. Polymer Chemistry 2016, 7 (25), 4246-4253.
47. Ballard, N.; Asua, J. M., Can We Push Rapid Reversible Deactivation Radical Polymerizations toward Immortality? ACS Macro Letters 2020, 9 (2), 190-196.
48. Lamb, J. R.; Qin, K. P.; Johnson, J. A., Visible-Light-Mediated, Additive-Free, and Open-to-Air Controlled Radical Polymerization of Acrylates and Acrylamides. Polymer Chemistry 2019, 10 (13), 1585-1590.
49. Rumble, J. R., CRC handbook of chemistry and physics. 2017.
50. Battino, R.; Rettich, T. R.; Tominaga, T., The Solubility of Oxygen and Ozone in Liquids. Journal of Physical and Chemical Reference Data 1983, 12 (2), 163-178.
51. Corrigan, N.; Rosli, D.; Jones, J. W. J.; Xu, J.; Boyer, C., Oxygen Tolerance in Living Radical Polymerization: Investigation of Mechanism and Implementation in Continuous Flow Polymerization. Macromolecules 2016, 49 (18), 6779-6789.
52. Mjalli, F. S.; Naser, J.; Jibril, B.; Alizadeh, V.; Gano, Z., Tetrabutylammonium Chloride Based Ionic Liquid Analogues and Their Physical Properties. Journal of Chemical & Engineering Data 2014, 59 (7), 2242-2251.
53. Fu, Q.; Xie, K.; McKenzie, T. G.; Qiao, G. G., Trithiocarbonates as Intrinsic Photoredox Catalysts and RAFT Agents for Oxygen Tolerant Controlled Radical Polymerization. Polymer Chemistry 2017, 8 (9), 1519-1526.
54. Carmean, R. N.; Sims, M. B.; Figg, C. A.; Hurst, P. J.; Patterson, J. P.; Sumerlin, B. S., Ultrahigh Molecular Weight Hydrophobic Acrylic and Styrenic Polymers through Organic-Phase Photoiniferter-Mediated Polymerization. ACS Macro Letters 2020, 9 (4), 613-618.
55. John F. Quinn, Leonie Barner, Christopher Barner-Kowollik, Ezio Rizzardo, and Thomas P. Davis, Reversible Addition-Fragmentation Chain Transfer Polymerization Initiated with Ultraviolet Radiation. Macromolecules 2002, 35 (20), 7620-7627.
56. Lowe, A. B., Thiol-ene “Click” Reactions and Recent Applications in Polymer and Materials Synthesis. Polymer Chemistry. 2010, 1 (1), 17-36.
57. Zhang, Z.; Zhu, X.; Zhu, J.; Cheng, Z.; Zhu, S., Thermal-Initiated Reversible Addition–Fragmentation Chain Transfer Polymerization of Methyl Methacrylate in the Presence of Oxygen. Journal of Polymer Science Part A: Polymer Chemistry 2006, 44 (10), 3343-3354.
58. Buback, M.; Frauendorf, H.; Günzler, F.; Vana, P., Electrospray Ionization Mass Spectrometric End-Group Analysis of PMMA Produced by Radical Polymerization Using Diacyl Peroxide Initiators. Polymer 2007, 48 (19), 5590-5598.
59. Xu, J.; Shanmugam, S.; Corrigan, N. A.; Boyer, C., Catalyst-Free Visible Light-Induced RAFT Photopolymerization. Controlled Radical Polymerization: Mechanisms 2015, 13, 247-267.
60. Song, Y.; Kim, Y.; Noh, Y.; Singh, V. K.; Behera, S. K.; Abudulimu, A.; Chung, K.; Wannemacher, R.; Gierschner, J.; Lüer, L.; Kwon, M. S., Organic Photocatalyst for ppm-Level Visible-Light-Driven Reversible Addition–Fragmentation Chain-Transfer (RAFT) Polymerization with Excellent Oxygen Tolerance. Macromolecules 2019, 52 (15), 5538-5545.
61. Jiang, J.; Ye, G.; Wang, Z.; Lu, Y.; Chen, J.; Matyjaszewski, K., Heteroatom-Doped Carbon Dots (CDs) as a Class of Metal-Free Photocatalysts for PET-RAFT Polymerization under Visible Light and Sunlight. Angewandte Chemie-International Edition 2018, 57 (37), 12037-12042.
62. Figg, C. A.; Hickman, J. D.; Scheutz, G. M.; Shanmugam, S.; Carmean, R. N.; Tucker, B. S.; Boyer, C.; Sumerlin, B. S., Color-Coding Visible Light Polymerizations to Elucidate the Activation of Trithiocarbonates Using Eosin Y. Macromolecules 2018, 51 (4), 1370-1376.
63. Allegrezza, M. L.; DeMartini, Z. M.; Kloster, A. J.; Digby, Z. A.; Konkolewicz, D., Visible and Sunlight Driven RAFT Photopolymerization Accelerated by Amines: Kinetics and Mechanism. Polymer Chemistry 2016, 7 (43), 6626-6636.
64. Fazende, K. F.; Gary, D. P.; Mota‐Morales, J. D.; Pojman, J. A., Kinetic Studies of Photopolymerization of Monomer‐Containing Deep Eutectic Solvents. Macromolecular Chemistry and Physics 2020, 221 (6).
65. Kubisa, P., Kinetics of Radical Polymerization in Ionic Liquids. European Polymer Journal 2020, 133(15), 109778.
66. Perrier, S.; Davis, T. P.; Carmichael, A. J.; Haddleton, D. M., First Report of Reversible Addition-fragmentation Chain Transfer (RAFT) Polymerisation in Room Temperature Ionic Liquids. Chemical Communication 2002, (19), 2226-2227.
67. Puttick, S.; Davis, A. L.; Butler, K.; Irvine, D. J.; Licence, P.; Thurecht, K. J., The Influence of Domain egregation in Ionic Liquids upon Controlled olymerisation Mechanisms: RAFT Polymerisation. Polymer Chemistry. 2013, 4 (5), 1337-1344.
68. Puttick, S.; Irvine, D. J.; Licence, P.; Thurecht, K. J., RAFT-Functional Ionic Liquids: towards Understanding Controlled Free Radical Polymerisation in Ionic Liquids. Journal of Materials Chemistry 2009, 19 (18), 2679-2682.
69. Kristofer J. Thurecht, P. N. G., Sarika Goel, Christopher Tuck,; Peter Licence, and Derek J. Irvine, Free-Radical Polymerization in Ionic Liquids: The Case for a Protected Radical. Macromolecules 2008, 41 (8), 2814-2820.
70. Simon Harrisson, S. R. M., and David M. Haddleton, Pulsed Laser Polymerization in an Ionic Liquid: Strong Solvent Effects on Propagation and Termination of Methyl Methacrylate. 2003.
71. Harrisson, S.; Mackenzie, S. R.; Haddleton, D. M., Unprecedented Solvent-Induced Acceleration of Free-radical Propagation of Methyl Methacrylate in Ionic Liquids. Chem Commun (Camb) 2002, (23), 2850-1.
72. Zhang, H.; Hong, K.; Jablonsky, M.; Mays, J. W., Statistical Radical Copolymerization of Styrene and Methyl Methacrylate in a Room Temperature Ionic Liquid. Chem Commun (Camb) 2003, (12), 1356-7.
73. Hongwei Zhang, K. H., and Jimmy W. Mays, Synthesis of Block Copolymers of Styrene and Methyl Methacrylate by Conventional Free Radical Polymerization in Room Temperature Ionic Liquids. Macromolecules 2002, 35, 5738−5741.