More Like this

1. RAFT step-growth polymerization via the Z-group approach and deconstruction by RAFT interchange

   https://doi.org/10.1039/d3sc06736j  

   Li, Jiajia; Tanaka, Joji; Li, Qing; Jing_Wang, Claire Jing; Sheiko, Sergei; Clouthier, Samantha Marie; Zhu, Jian; You, Wei (March 2024, Chemical Science)

   RAFT step-growth polymerizationviathe Z-group approach was developed, offering a facile method to prepare deconstructable (multiblock) polymers by combining RAFT chain-growth polymerization and RAFT interchange. 

   more » « less
2. Sustainable thermoplastic elastomers produced via cationic RAFT polymerization

   https://doi.org/10.1039/D0PY01640C  

   Spring, Scott W.; Smith-Sweetser, Red O.; Rosenbloom, Stephanie I.; Sifri, Renee J.; Fors, Brett P. (March 2021, Polymer Chemistry)

   null (Ed.)

   Plastic production continually increases its share of global oil consumption. Thermoplastic elastomers (TPEs) are a necessary component of many industries, from automotive and construction to healthcare and medical devices. To reduce the environmental burden of TPE production on the world, we developed two new ABA triblock copolymers synthesized through cationic reversable addition–fragmentation chain transfer (RAFT) polymerization from renewable monomers. Using poly(isobutyl vinyl ether) (PIBVE) as the soft block and either poly( p -methoxystyrene) (PMOS) or poly(2,3-dihydrofuran) (PDHF) as the hard blocks, we produced triblock copolymers with varying volume fractions and characterized their material properties. PDHF-PIBVE-PDHF is sourced almost entirely from simple alcohols and exhibits mechanical properties comparable to those of commercial TPEs. This effort demonstrates the utility of cationic RAFT for the production of sustainable TPEs. 

   more » « less
3. Transformation of gels via catalyst-free selective RAFT photoactivation

   https://doi.org/10.1039/C9PY00213H  

   Shanmugam, Sivaprakash; Cuthbert, Julia; Flum, Jacob; Fantin, Marco; Boyer, Cyrille; Kowalewski, Tomasz; Matyjaszewski, Krzysztof (May 2019, Polymer Chemistry)

   This work explores the concept of structurally tailored and engineered macromolecular (STEM) networks by proposing a novel metal-free approach to prepare the networks. STEM networks are composed of polymer networks with latent initiator sites affording post-synthesis modification. The proposed approach relies on selectively activating the fragmentation of trithiocarbonate RAFT agent by relying on visible light RAFT iniferter photolysis coupled with RAFT addition–fragmentation process. The two-step synthesis explored in this work generates networks that are compositionally and mechanically differentiated than their pristine network. In addition, by careful selection of crosslinkers, conventional poly(ethylene glycol) dimethacrylate ( M n = 750) or trithiocarbonate dimethacrylate crosslinker (bis[(2-propionate)ethyl methacrylate] trithiocarbonate (bisPEMAT)), and varying concentrations of RAFT inimer (2-(2-( n -butyltrithiocarbonate)-propionate)ethyl methacrylate (BTPEMA)), three different types of primary (STEM-0) poly(methyl methacrylate) (PMMA) networks were generated under green light irradiation. These networks were then modified with methyl acrylate (MA) or N , N -dimethylacrylamide (DMA), under blue light irradiation to yield STEM-1 gels that are either stiffer or softer with different responses to polarity (hydrophilicity/hydrophobicity). 

   more » « less
4. Photo-Iniferter RAFT Synthesis of Versatile, Nonalternating Poly(acrylate- co -isocyanides)

   https://doi.org/10.1021/acs.macromol.4c01610  

   Čamdžić, Lejla; Stache, Erin E (October 2024, Macromolecules)
5. PET‐RAFT Polymerization of Star Polymers with Folded ortho ‐Phenylene Cores

   https://doi.org/10.1002/marc.202300094  

   Bradford, Kate G. E.; Kirinda, Viraj C.; Gordon, Emma A.; Hartley, C. Scott; Konkolewicz, Dominik (May 2023, Macromolecular Rapid Communications)

   Abstract ortho‐Phenylenes are one of the simplest classes of aromatic foldamers, adopting helical geometries because of aromatic stacking interactions. The folding and misfolding ofortho‐phenylenes are slow on the NMR timescale at or below room temperature, allowing detection of folding states using¹H NMR spectroscopy. Herein, anortho‐phenylene hexamer is coupled with a RAFT chain transfer agent (CTA) on each repeat unit. A variety of acrylic monomers are polymerized onto the CTA‐functionalizedortho‐phenylene using PET‐RAFT to yield functionalized star polymers withortho‐phenylene cores. The steric bulk of the acrylate monomer units as well as the chain length of each arm of the star polymer is varied.¹H NMR spectroscopy shows that the folding of theortho‐phenylenes do not vary, providing a robust helical core for star polymer systems. 

   more » « less