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Developments in Reversible Deactivation Radical Polymerization Carlos Miguel Rocha Abreu Carlos Miguel Rocha Abreu Developments in Reversible Deactivation Radical Polymerization: Developments inDevelopments Reversible Deactivation Radical Polymerization: New Ecofriendly Catalytic Systems and New Ecofriendly Catalytic Systems and Vinyl Chloride (co)Polymerization Methods Vinyl Chloride (co)Polymerization Methods PhD Thesis in Chemical Engineering, supervised by Professor Doctor Jorge Fernando Jordão Coelho, Professor Doctor Arménio Coimbra Serra and Professor Doctor Krzysztof Matyjaszewski, submitted to the Department of Chemical Engineering, Faculty of Science and Technology, University of Coimbra OIMBRA C Agosto, 2017 E D NIVERSIDADE NIVERSIDADE U Carlos Miguel Rocha Abreu Developments in Reversible Deactivation Radical Polymerization: New Ecofriendly Catalytic Systems and Vinyl Chloride (co)Polymerization Methods Thesis submitted to the Faculty of Sciences and Technology of the University of Coimbra, to obtain the Degree of Doctor in Chemical Engineering. Coimbra 2017 Carlos Miguel Rocha Abreu Developments in Reversible Deactivation Radical Polymerization: New Ecofriendly Catalytic Systems and Vinyl Chloride (co)Polymerization Methods Thesis submitted to the Faculty of Sciences and Technology of the University of Coimbra, to obtain the Degree of Doctor in Chemical Engineering. Advisors: Prof. Dr. Jorge Fernando Jordão Coelho Prof. Dr. Arménio Coimbra Serra Prof. Dr. Krzysztof Matyjaszewski Host institutions: University of Coimbra Carnegie Mellon University Financing: Portuguese Foundation for Science and Technology (FCT) Doctoral degree grant: SFRH/BD/88528/2012 Coimbra 2017 Financial support: À minha mãe (in memoriam), Acknowledgments Acknowledgments O meu Muito Obrigado a todos aqueles que de modo directo ou indirecto contribuíram para o sucesso deste trabalho. Ao Professor Jorge Coelho, meu orientador científico. Agradeço por ter acreditado e confiado em mim desde o início, me ter motivado e concedido as melhores oportunidades ao longo dos últimos anos. Agradeço também toda a ajuda prestada, todo o conhecimento transmitido e o facto de me ter proporcionado uma incrível experiência em Pittsburgh (Estados Unidos da América). Sem dúvida que contribuiu imenso para o meu desenvolvimento. Ao Professor Arménio Serra, pela confiança demonstrada, pela sua disponibilidade e por todas as discussões, conselhos e sugestões ao longo do trabalho. To Professor Krzysztof Matyjaszewski I want to express my deepest gratitude for welcoming in his laboratory at Carnegie Mellon University and for the helpful discussions, comments and advices. I'm grateful for such wonderful opportunity. I would also like to extend my great appreciation to his wife for having me at home during my stay at Pittsburgh. I’ve found a home far from home with you both. A todos os membros do Polymer Synthesis and Characterization (Polysyc), em especial ao pessoal do laboratório B37, pelo bom ambiente de trabalho criado e pelas discussões de resultados durante o nosso duro processo de desenvolvimento de novos sistemas de RDRP. To the group members of the Matyjaszewski Polymer Group, it was a pleasure to meet you all and have the chance to work with you. Thank you for the good advices, support, friendship and fun we shared during my stay. Ao Departamento de Engenharia Química e a todos os seus funcionários, pelas condições proporcionadas. À Fundação para a Ciência e Tecnologia (FCT), pelo financiamento deste trabalho. VII Acknowledgments E, por fim, mas não menos importante, a toda a minha família e todos os meus amigos, a minha eterna gratidão pelo esforço, pelo incentivo e por terem apoiado sempre todas as minhas decisões. VIII Abstract Abstract The aim of this work was the study and development of new ecofriendly catalytic systems for reversible deactivation radical polymerization (RDRP). It was also a goal the development of new vinyl chloride (VC) (co)polymerizations systems using RDRP methods. Atom transfer radical polymerization (ATRP) is among the most efficient, versatile and robust RDRP techniques. The new generation of catalytic systems for RDRP of vinyl monomers should be non-toxic, inexpensive and provide fast polymerizations in environmentally friendly media. In this context, in the present work Food and Drug Administration (FDA) approved inorganic sulfites such as sodium dithionite (Na2S2O4), sodium metabisulfite (Na2S2O5), and sodium bisulfite (NaHSO3) were found as a new class of very efficient reducing agents and supplemental activators (SARA) for ATRP. In combination with catalytic amounts of Cu(II)Br2/Me6TREN (Me6TREN: tris[2- (dimethylamino)ethyl]amine) in dimethyl sulfoxide (DMSO) at ambient temperature (30 ºC), poly(methyl acrylate) (PMA) with controlled molecular weight, low dispersity (Ð < 1.05), and well-defined chain-end functionality, was synthetized as a proof-of-concept. In addition, an unusual synergistic effect between an ionic liquid, 1-butyl-3- methylimidazolium hexafluorophosphate (BMIM-PF6), and DMSO mixtures was found for this ecofriendly SARA ATRP. The novel developed inorganic sulfites catalyzed ATRP was also successfully extended to the (co)polymerization of activated vinyl monomers, such as methyl acrylate (MA), n- butyl acrylate (n-BA), methyl methacrylate (MMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA), in ecofriendly solvents (alcohols and alcohol/water mixtures) at ambient temperature. In this system, the use of inorganic sulfites and ecofriendly solvents (alcohol-water mixtures are inexpensive and have low boiling points) is a remarkable advantage for the possibility of scaling-up of the ATRP method. The aqueous SARA ATRP using inorganic sulfites was successfully developed for the first time. This study methodically investigated the different parameters of SARA ATRP for the synthesis of well-defined water-soluble polymers (e.g., poly[oligo(ethylene oxide) IX Abstract methyl ether acrylate] (POEOA)) in aqueous media catalyzed by Cu(II)Br2/tris(2- pyridylmethyl)amine (TPMA) (<30 ppm) using a slow feeding of inorganic sulfites at room temperature. The developed system was also extended to the synthesis of block copolymers using a “one-pot” method. As proof-of-concept, under biologically relevant conditions, the aqueous SARA ATRP using inorganic sulfites was successfully applied to synthesize a well-defined bovine serum albumin protein-polymer (BSA-[P(OEOA480)30]) hybrid. The development of efficient RDRP methods for control of nonactivated vinyl monomers (e.g., vinyl acetate, N-vinylpyrrolidone and vinyl chloride) remains an important challenge. Poly(vinyl chloride) (PVC) is one of the most widely consumed polymers worldwide due to its general versatility and low cost. Conventional free radical polymerization (FRP) of VC is the only available industrial process to produce the polymer in large scale. The several intrinsic limitations of FRP triggered interest in synthesizing this polymer by RDRP methods. Until 2012, the most successful RDRP of VC had been achieved by single electron transfer degenerative chain transfer living radical polymerization (SET-DTLRP) or Metal Catalyzed RDRP (termed SET-LRP). In this context, in the present work reversible addition-fragmentation chain transfer (RAFT) polymerization of VC was developed. The success of the RAFT polymerization process (control over the molecular weight, the molecular weight distribution and the molecular architecture of the resulting polymers) is strongly related to the appropriate selection of the RAFT agent (usually termed CTA). Cyanomethyl methyl(phenyl)carbamodithioate (CMPCD) was shown to be an efficient RAFT agent. The results demonstrated that a careful selection of the reaction conditions (initiator type and concentration, solvent type and concentration, temperature) is critical for achieving PVC products with controlled features (the lowest dispersity ever reported for PVC obtained by any RDRP method, Ð ~ 1.4). Structural analysis, via 1H-NMR and MALDI- TOF-MS, revealed that the PVC chains contained well preserved functional groups and no structural defects. Moreover, the “living” nature of the PVC that was synthesized via RAFT polymerization method was confirmed by successful chain extension and PVC- based block copolymerization experiments. X Abstract The work continued with the synthesis of PVC by nitroxide-mediated polymerization (NMP) using the SG1-based BlocBuilder alkoxyamine at low temperature (30 and 42 °C). With a judicious selection of the polymerization conditions (dichloromethane (DCM) as solvent using 1/1 monomer-to-solvent ratio), first order kinetics and linear evolutions of the molecular weight with VC conversion were obtained with decreasing Ð down to 1.6- 1.4. The structural characterizations (1H-NMR and 31P-NMR) of the resulting PVC suggested the existence of very small content of structural defects and the high preservation of the chain-end functional groups (~91% SG1 chain-end functionality). PVC-SG1 macroinitiators were successfully used in chain extension experiments using VC, MMA and mixture of monomers (90% of MMA and 10% of styrene (S)) and confirmed the “livingness” of the PVC-SG1 macroinitiators, giving access to different PVC-based block copolymers. Even though water is the ideal solvent in terms of nontoxicity, very few examples of monomers/polymers are water-soluble. Therefore, alternative green organic solvents are highly desirable. Thus, considering the very promising results that were obtained in previous parts of this work, cyclopentyl methyl ether (CPME) was successfully introduced
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