Cover Image, Volume 66, Issue 11

Abstract

The cover image, by James Gardiner et al., is based on the Research Article 4‐Halogeno‐3,5‐dimethyl‐1H‐pyrazole‐1‐carbodithioates: versatile reversible addition fragmentation chain transfer agents with broad applicability, DOI: . Note: MAMs and LAMs are acronyms for more and less activated monomers.

Tailoring Polymer Dispersity by RAFT Polymerization: A Versatile Approach

“…By using CTA 2, PMMA of slightly higher Ɖ (1.23) was obtained, S2, Entry 1). When the even lower transfer activity of 2-cyanobutan-2-yl 4-chloro-3,5-dimethyl-1H-pyrazole-1-carbodithioate (CTA 3) was used, 53 PMMA with monomodal MWDs and a Ɖ of 1.65 could be obtained (Table S1, Entry 1). As expected, employing CTAs with much lower activity than CTA 3 (i.e., methyl 2-[methyl(4-pyridinyl)carbamothioylthio]propionate (CTA 5), 2-cyanopropan-2-yl N-methyl-N-(pyridin-4-yl)carbamodithioate (CTA 6), cyanomethyl methyl(phenyl)carbamodithioate, 2-cyanobutan-2-yl 3,5-dimethyl-1H-pyrazole-1-carbodithioate, and methyl 2-(butylthiocarbonothioylthio)propanoate) resulted in notable low-MW tailing, very poor CTA efficiency, and bimodal MWDs, as evident by size exclusion chromatography (SEC) (Scheme S1; Figures S2B-S2F; Table S2, Entries 2-6).…”

“…As expected, employing CTAs with much lower activity than CTA 3 (i.e., methyl 2-[methyl(4-pyridinyl)carbamothioylthio]propionate (CTA 5), 2-cyanopropan-2-yl N-methyl-N-(pyridin-4-yl)carbamodithioate (CTA 6), cyanomethyl methyl(phenyl)carbamodithioate, 2-cyanobutan-2-yl 3,5-dimethyl-1H-pyrazole-1-carbodithioate, and methyl 2-(butylthiocarbonothioylthio)propanoate) resulted in notable low-MW tailing, very poor CTA efficiency, and bimodal MWDs, as evident by size exclusion chromatography (SEC) (Scheme S1; Figures S2B-S2F; Table S2, Entries 2-6). 53 As such, CTA 3 was selected as a suitable low-activity CTA to further study the polymerization of MMA. Pleasingly, by altering the ratio between the two RAFT agents (CTA 1 to CTA 3), the Ɖ of PMMA could be successfully tuned between 1.13-1.65 (Figures 2A and S3; Tables 1, S1, and S3 Entries 1-5).…”

A Critical Survey of Dithiocarbamate Reversible Addition‐Fragmentation Chain Transfer (RAFT) Agents in Radical Polymerization

“…The 2‐cyano‐2‐butyl 4‐chloro‐3,5‐dimethyl‐1 H ‐pyrazole‐1‐carbodithioate ( 14 ) provided a poly(MMA) with the anticipated molar mass and Ð as low as 1.3 at high monomer conversion . Low dispersities ( Ð ≤ 1.2) and molar mass control were also achieved for homo‐ and copolymerizations of the LAM, VAc, albeit with some retardation . Low dispersity poly(DMAm)‐ block ‐poly(VAc), a poly(MAM)‐ block ‐poly(LAM), was also prepared.…”

“…The data reported in Figure 6 help in understanding the difference in activity between N , N ‐dialkyl ( 44 – 48 ) or N ‐alkyl‐ N ‐aryl ( 41 – 43 ) and those where the nitrogen is part of an aromatic ring system ( 15 – 25 ). However, a basis for discriminating between the individual members of these classes, or between these and dithiocarbamates with intermediate activity ( 26 – 40 ), is less obvious.…”

In Focus Emerging Polymer Technologies Summit (EPTS'16)

“…In addition, the Summit included many other keynote and invited speakers, and a raft of young and early career scientists' contributions that formed an integral part of the EPTS'16 scientific program. This In Focus comprises five papers . Unfortunately, many of the speakers did not elect to take advantage of this special In Focus, however, note that Professor Moad's plenary presentation (Co)polymerization of the conjugated diene monomers: butadiene, isoprene and chloroprene has already been published in Polymer International …”