N-heterocyclic Carbene Containing Homogeneous Ru Catalyst for Aqueous Atom Transfer Radical Polymerization of Water-soluble Vinyl Monomers

From non-conventional ideas to multifunctional solvents inspired by green chemistry: fancy or sustainable macromolecular chemistry?

“…3,4 This entirely new method is thought to hold great potential due to its high versatility in polymerizations of diverse monomers, such as (meth)acrylates, [5][6][7][8][9][10][11] acrylamides [12][13][14][15][16] but also charged 17,18 or acidic [19][20][21] compounds. Considering the polymerization mechanism, the most frequently used types of RDRP techniques should be (1) atom transfer radical polymerization (ATRP), catalysed mainly by transition metal complexes, 9,[22][23][24][25][26][27][28] (Fig. 1a) (2) nitroxide-mediated polymerization (NMP), where initiation is caused by -N-Oradicals retrieved from alkoxylamines [29][30][31][32] (Fig.…”

“…Another emphasized aspect is ensuring the possibility of degradation of products after their service time, which demonstrates that green chemistry draws attention to the whole process of production, exploitation, and recycling or removal from the environment. 58 Considering controlled polymerizations, the application of green chemistry principles often turns up to be at least challenging as it usually requires strict conditions such as specific, high temperature, [59][60][61][62] deoxygenated reaction mixture 28,31,63,64 and large volumes of substrates, which are rarely fully consumed. 65,66 In many cases, the occurring side reactions decrease the control over the process, resulting in high dispersity 16,49 and low initiation efficiency.…”

“…208 Although reversible-deactivation radical polymerizations are usually applied in order to obtain polymers of predefined structure and narrow molecular mass distribution, they are ideally suited to transform them into diagnostic systems, especially when the analyte is able to catalyse the reaction, due to the fact, that one catalyst molecule leads to the creation of many polymer molecules. 16 As the ATRP catalyst complex typically consists of a transition metal such as Cu, 9,23,24,63,135,161 Fe, 5,22,27,60,111,140 Ru 28,209,210 or Os, 211 some proteins, and enzymes containing metal cations have already been tested in this role. 13,35,206 Therefore, molecules such as hemoglobin are a crucial part of red cells in human blood, and can also play the role.…”

“…Considering controlled polymerizations, the application of green chemistry principles often turns up to be at least challenging as it usually requires strict conditions such as specific, high temperature, 59–62 deoxygenated reaction mixture 28,31,63,64 and large volumes of substrates, which are rarely fully consumed. 65,66 In many cases, the occurring side reactions decrease the control over the process, resulting in high dispersity 16,49 and low initiation efficiency.…”

Recent Advances in Zeolites‐Catalyzed Biomass Conversion to Hydroxymethylfurfural: The Role of Porosity and Acidity

“…[68] Although homogeneous catalysts offer many advantages for the conversion of biomass to 5-HMF, they suffer from significant drawbacks such as equipment corrosion, complex recovery, and regeneration processes. [69] For instance, the use of concentrated sulfuric acid as a catalyst leads to a significant waste of energy and materials, due to its nonreusability and the need for sulfate separation and product purification. [70] In contrast, heterogeneous catalysts offer a more environmentally friendly approach to biomass conversion with the advantages of being renewable, easy to separate, and nonpolluting.…”