The new generation of catalytic systems for Controlled/"Living" Radical Polymerization (CLRP) of vinyl monomers should be non-toxic, inexpensive and provide fast polymerizations in environmentally friendly media. Herein, we report the successful ambient temperature ATRP of several vinyl monomers (MA, n-BA, MMA and DMAEMA) catalyzed by inorganic sulfites (Na S O and Na S O) and small amounts of a Cu(II)Br /Me TREN system in alcohol-water mixtures. The

Inorganic sulfites such as sodium dithionite (Na 2 S 2 O 4 ), sodium metabisulfite (Na 2 S 2 O 5 ), and sodium bisulfite (NaHSO 3 ) have been studied as reducing agents for atom transfer radical polymerization (ATRP). They act not only as very efficient reducing agents but also as supplemental activators for SARA (supplemental activator and reducing agent) ATRP of methyl acrylate in DMSO at ambient temperature. In combination with Cu(II)Br 2 /Me 6 TREN, they produced poly(methyl acrylate) with controlled molecular weight, low dispersity (M w /M n = 1.05), and well-defined chain-end functionality. Sulfites are eco-friendly, approved by FDA as food and beverage additives, and used commercially in many industrial processes.

Controlled/“living” radical polymerization (CLRP) of vinyl chloride (VC) via the reversible addition–fragmentation chain transfer (RAFT) process is reported for the first time. The cyanomethyl methyl­(phenyl)­carbamodithioate (CMPCD) was found to be an efficient RAFT agent enabling the CLRP polymerization of VC monomer under certain experimental conditions. Two different radical initiators, having very distinct half-life times at room temperature, were employed in this study. The kinetic studies of RAFT polymerization of VC show a linear increase of the molecular weight with the monomer conversion and the lowest polydispersity (PDI) ever reported for poly­(vinyl chloride) (PVC) synthesized with CLRP method (PDI ∼ 1.4). The resulting PVC was fully characterized using the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), 1H nuclear magnetic resonance spectroscopy (1H NMR), and gel permeation chromatography (GPC) techniques. The 1H NMR and MALDI-TOF-MS analysis of PVC prepared via RAFT polymerization method have shown the absence of structural defects and the presence of chain-end functional groups. The “livingness” of the PVC was also confirmed by a successful reinitiation experiment. The suitability of the RAFT agent was also confirmed via high-level ab initio molecular orbital calculations.

A series of polyacrylonitrile-block-poly(butyl acrylate) (PAN-b-PBA) copolymers were prepared by supplemental activator reducing agent atom transfer radical polymerization (SARA ATRP). These copolymers were then used as precursors to pyrolytic nanostructured carbons with the PAN block serving as a nitrogen-rich carbon precursors and the PBA block acting as a sacrificial porogen. The study revealed that while the size of mesopores can be controlled by the size of the porogenic block, the connectivity of pores diminishes with the decrease of the overall molecular weight of the precursor. This partial loss of mesopore connectivity was attributed to the weaker phase segregation between the blocks of shorter lengths inferred from the shape of small-angle X-ray scattering profiles and from the crystallinity of polyacrylonitrile phase.

A very fast and controlled atom transfer radical (co)polymerization (ATRP) of acrylates, methacrylates, styrene, and vinyl chloride is reported in a single dipolar aprotic solvent, sulfolane, with the use of ppm amount of the copper catalyst. The observed rates of polymerization (k p app ) of the monomers studied are similar to those reported using dimethyl sulfoxide (DMSO) and other polar solvents typically employed in single electron transfer (SET)-mediated atom transfer radical polymerization (ATRP) processes. As proof-of-concept, ABA type block copolymers of polystyrene-b-poly(vinyl chloride)-b-polystyrene and poly(methyl acrylate)-b-poly(vinyl chloride)-bpoly(methyl acrylate) were prepared for the first time using a reversible deactivation radical polymerization (RDRP) method in a single solvent. The quantitative preservation of halide chain-ends was confirmed by 1 H NMR and MALDI-TOF analysis as well as by the complete shift of the GPC traces. The results presented establish an innovative and robust system to afford a vast portfolio of (co)polymers in a single widely used industrial solvent.

The current trend in developing next‐generation LRP systems and in particular ATRP involves reduction, elimination, and/or replacement of toxic and highly expensive catalysts and solvents with environmently friendly ones. Here, the unexpected, accelerated, ambient‐temperature ATRP of methyl acrylate catalyzed by a Fe(0)/CuBr2/Me6TREN system in a mixture of water and inexpensive and environmentally more friendly alcohols (methanol, ethanol, and 1‐propanol) is reported. The data presented open up the possibility of using fast ATRP catalyzed by a mixed transition‐metal catalyst system in solvents that are inexpensive, eco‐friendly, and have low boiling points.

Aqueous supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) using inorganic sulfites was successfully carried out for the first time. Under optimized conditions, a well-controlled poly[oligo(ethylene oxide) methyl ether acrylate] (POEOA) was obtained with <30 ppm of soluble copper catalyst using tris(2-pyridylmethyl)amine (TPMA) ligand in the presence of an excess of halide salts (e.g. NaCl). Inorganic sulfites (e.g. Na2S2O4) were continuously fed into the reaction mixture. The mechanistic studies proved that these salts can activate alkyl halides directly and regenerate the activator complex. The effects of the feeding rate of the SARA agent (inorganic sulfites), ligand and its concentration, halide salt and its concentration, sulfite used, and copper concentration, were systematically studied to afford fast polymerizations rates while maintaining the control over polymerization. The kinetic data showed linear first-order kinetics, linear evolution of molecular weights with conversion, and polymers with narrow molecular weight distributions (Đ ~1.2) during polymerization even at relatively high monomer conversions (~80%). “One-pot” chain extension and “one-pot” block copolymerization experiments proved the high chain-end functionality. The polymerization could be directly regulated by starting or stopping the continuous feeding of the SARA agent. Under biologically relevant conditions, the aqueous SARA ATRP using inorganic sulfites was used to synthesize a well-defined protein-polymer hybrid by grafting of P(OEOA480) from BSA-O-[iBBr]30.

Supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of acrylates, methacrylates, styrene and vinyl chloride was successfully performed in sulfolane/water mixtures using ppm amounts of soluble copper.