Article
Polymer Science
Vanessa A. Pereira, Patricia Mendonca, Jorge F. J. Coelho, Armenio C. Serra
Summary: A bio-based eutectic mixture was used as a solvent for the atom transfer radical polymerization (ATRP) of hydrophobic and hydrophilic monomers, resulting in well-defined homopolymers and amphiphilic block copolymers. This unique solvent system provides a convenient method for the synthesis of ABs.
Article
Materials Science, Paper & Wood
Muhammad Asif Iqbal, Toheed Akhter, Muhammad Faheem, Asif Mahmood, Waheed Al-Masry, Sohail Nadeem, Sadaf Ul Hassan, Chan Ho Park
Summary: We synthesized a thermoresponsive polymer with a narrow molecular weight distribution using organic photo-redox-catalyzed atom transfer radical polymerization (O-ATRP). The O-ATRP was mediated by a photoredox catalyst 1,2,3,5-tetrakis (carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) under visible light irradiation. The polymerization of polymethyl methacrylate (PMMA) chains from a hydroxypropyl cellulose (HPC)-based macroinitiator was characterized using various analytical methods. The resulting PMMA-grafted HPC (PMMA-g-HPC) showed a widened lower critical solution temperature (LCST) window and an inverse pH dependency of the LCST, making it promising for various applications including drug delivery systems.
Article
Polymer Science
Anna Mielanczyk, Maria Kupczak, Olesya Klymenko, Lukasz Mielanczyk, Sebastian Arabasz, Krystian Madej, Dorota Neugebauer
Summary: Well-defined miktoarm star-shaped polymers and linear block copolymers have been successfully synthesized based on a heterofunctional glucose derivative initiator, N,N'-dimethylaminoethyl methacrylate (DMAEMA), using a combination of atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) techniques followed by click reactions. The presence of salts in polymer solutions affects the phase transformation and aggregate sizes, with the critical aggregation concentration (CAC) decreasing with decreasing DMAEMA unit content. TEM and AFM analysis reveal the microstructure changes in samples with different compositions of polyester arms.
Article
Polymer Science
Evgeniia Salomatina, Aleksander Pikulin, Dmitry Semenov, Ivan Grishin, Natalia Kirillova, Larisa Smirnova
Summary: A new method of block-copolymer synthesis using a multifunctional Si-organic chain transfer agent is presented. The method allows for a wider choice of monomers and is applicable for obtaining block copolymers with wide molecular weight distribution. The synthesis can be completed in a few hours at moderate temperatures and does not involve sulfur-based or metalorganic compounds, making it suitable for various applications. The resulting polymer molecular weight can be controlled by adjusting the concentrations of the initiator and Si-Cl-based agent.
Article
Polymer Science
Min Su, Yu-Jing Sheng, Yu-Jiao Chen, Tao Li, Quan-Xi Shi, Hang Xiao, Meng-Qin Pu, Hongli Bao, Wen-Ming Wan
Summary: A versatile living polymerization method is reported, which allows the precise synthesis of narrow distributed polystyrenes through the introduction of a well-established all-in-one covalent-anionic-radical Barbier strategy, using a wide variety of organohalides as initiators under mild conditions.
Article
Polymer Science
Aurel Diacon, Edina Rusen, Florica Rizea, Adi Ghebaur, Daniela Berger, Raluca Somoghi, Andreea Matei, Petru Palade, Oana Tutunaru
Summary: The study developed an ATRP process for MMA polymerization using Fe(CO)(5) as co-initiator, demonstrating controlled characteristics and producing magnetic PMMA particles. The particles have porous characteristics and magnetic properties, making them suitable for use as catalyst supports, separation processes, or biomedical applications.
EUROPEAN POLYMER JOURNAL
(2021)
Article
Polymer Science
Mohamed Naguib, Kate L. Nixon, Daniel J. Keddie
Summary: This study reports the synthesis of two novel trithiocarbonate RAFT agents for bottlebrush synthesis via ROMP grafting-through polymerization. The correlation between the monomer type, degree of polymerization, and RAFT agent structure has been investigated. The results reveal that the properties of the resulting polymers are influenced by the monomer type, degree of polymerization, and RAFT agent structure.
Article
Polymer Science
Yi Wang, Francesca Lorandi, Marco Fantin, Krzysztof Matyjaszewski
Summary: Polymerizations in aqueous dispersed media benefit from good heat transfer, low viscosity, low content of volatile compounds, and established industrial use. The implementation of ATRP in dispersed media has highlighted the possibility of achieving improved livingness and producing a variety of macromolecular architectures. ATRP techniques employing low-ppm catalyst loadings have enabled access to a larger variety of polymer architectures and functional polymer particles, which have found applications in molecular recognition, drug delivery, bio-quantification, and advanced coatings.
Article
Engineering, Chemical
Ki Jung Kim, Yunmi Chae, Seong Jin An, Jin Hui Jo, Sungmin Park, Won Seok Chi
Summary: This study investigates microphase-separated structured PI-POEM graft copolymer membranes, which have controllable POEM concentrations and the ability to modify material properties. The results show that PI-POEM graft copolymer membranes exhibit high CO2 affinity and separation performance, making them promising for CO2 separation processes.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Polymer Science
Daniel A. Corbin, Blaine G. McCarthy, Zach van de Lindt, Garret M. Miyake
Summary: This study focused on synthesizing radical cations of photoredox catalysts for organocatalyzed ATRP to investigate deactivation mechanisms. The results showed that increasing radical cation concentrations improved polymerization control in O-ATRP.
Article
Polymer Science
Kate G. E. Bradford, Robert D. Gilbert, M. A. Sachini N. Weerasinghe, Simon Harrisson, Dominik Konkolewicz
Summary: In this study, spontaneous gradient polymerization was investigated using ATRP and RAFT methods. It was found that RAFT polymerization with a chain transfer agent (CTA) compatible with both methacrylic and acrylic monomers showed the best control over polymer structure. On the other hand, ATRP led to slightly higher dispersity polymers with decreased correlation between experimental and theoretical molecular weights. Overall, RAFT offered a simpler approach to gradient polymers when a CTA compatible with both monomers was selected.
Article
Chemistry, Multidisciplinary
Joji Tanaka, Noel Edward Archer, Michael Jeffery Grant, Wei You
Summary: In this study, RAFT step-growth polymerization was achieved by combining RAFT and step-growth polymerization mechanisms, resulting in backbone repeat units with a pendant RAFT agent that can form molecular brush polymers in a second polymerization step. The cleavable backbone functionality allows the transformation of brushlike polymers into linear chains of uniform size under stimuli.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Polymer Science
Jiayan Shi, Chunhua Wei, Min Shen, Tingting Pan, Yanqing Tian
Summary: Two new block copolymers (P1 and P2) containing platinum porphyrin-based phosphorescent probes with different molar ratios of polydimethylsiloxane (PDMS) and isobutyl methacrylate (IBM) were successfully synthesized via atom transfer radical polymerization (ATRP) with narrow polydispersity smaller than 1.21. The polymer with higher PDMS content exhibited better oxygen sensitivity, pressure sensitivity, and faster response time. The pressure sensitivity of the polymer was significantly influenced by temperature, with P1 having a high pressure sensitivity of 0.82%/kPa at 50 wt% PDMS content.
Article
Polymer Science
James B. Young, Jared Bowman, Cabell B. Eades, Alexander J. Wong, Brent S. Sumerlin
Summary: Controlled radical polymerization techniques allow for the synthesis of polymers with specific molecular weights and architectures. In this study, the role of light in triggering thermal depolymerization of polymers synthesized through reversible-addition-fragmentation chain-transfer (RAFT) polymerization was investigated. By targeting specific electronic transitions, the depolymerization efficiency was enhanced.
Article
Polymer Science
Mengmeng Li, Lin Zhou, Ziqi Zhang, Qi Wang, Jiani Gao, Shiping Zhang, Lin Lei
Summary: In this study, a well-defined block copolymer was successfully synthesized using triarylsulfonium hexafluorophosphate salt as the organocatalyst for both photo-ATRP and ROP. The conversions of the two polymerizations were higher in a one-pot synthesis compared to separate polymerizations, indicating a promotion of each other. This efficient method is suitable for preparing complex block copolymers.
