Article
Chemistry, Multidisciplinary
Jaepil Jeong, So Young An, Xiaolei Hu, Yuqi Zhao, Rongguan Yin, Grzegorz Szczepaniak, Hironobu Murata, Subha R. Das, Krzysztof Matyjaszewski
Summary: This study presents an approach to convert biomass RNA into an acrylic crosslinker by acyl imidazole chemistry, allowing for the fabrication of materials with tunable properties. It also explores reversible-deactivation radical polymerization methods and metallization of the biomass RNA-based material, expanding the opportunities in biomass-based biomaterial fabrication.
Article
Polymer Science
Nathaniel Corrigan, Francisco J. Trujillo, Jiangtao Xu, Graeme Moad, Craig J. Hawker, Cyrille Boyer
Summary: This research demonstrates the controlled synthesis of graft and branched copolymers without intermediate purification using one-pot or one-pass processes. The formation of poly(methacrylate) copolymers with pendent reversible addition-fragmentation chain transfer (RAFT) agent functionalities was performed through selective photoactivation, followed by a nonselective photoinduced chain extension to provide tailored graft copolymers. By alternating the light sources, a range of macromolecular architectures could be prepared from the same starting materials, showing the versatility and flexibility of this approach.
Article
Polymer Science
Parker T. Boeck, Noel E. Archer, Joji Tanaka, Wei You
Summary: Commercially available N-aromatic substituted bismaleimides were used in RAFT step-growth polymerization with a bifunctional RAFT agent, resulting in polymers with moderate to high molecular weights. This advancement allows for the preparation of graft copolymers in a straightforward manner at a larger scale, increasing the accessibility of the previously reported methodology.
Article
Polymer Science
Alexandros E. Alexakis, Olivia R. Wilson, Eva Malmström
Summary: The combination of RAFT polymerization and PISA can produce monodisperse nanolatexes. This study demonstrates the synthesis of reproducible bimodal nanolatexes by extending protonated PDMAEMA with MMA in water and provides the first imaging data. The bimodality is induced by the hydrophilic Z-group of the RAFT agent, which has been reported to cause bimodal molecular weight distributions in RAFT-mediated PISA. The advantages of such nanolatexes in coating applications are briefly explored, including their one-pot synthesis, higher contact angle against water when adsorbed on cellulose filter paper, and morphological arrangement dependent on the drying protocol.
Article
Polymer Science
Yanlin Shi, Sung-Po R. Chen, George Fragkiadakis, Daniele Parisi, Virgil Percec, Dimitris Vlassopoulos, Michael J. Monteiro
Summary: The shape, breadth, and average molecular weight of the overall molecular weight distribution (MWD) are important for determining polymer properties. Traditional methods can only achieve desired Gaussian distribution through complex modeling, while living radical polymerization provides a simpler route. Blending low-reactive RAFT agents allows the construction of square, slanted, and chair-like MWDs, providing control over MWD shape and breadth. This blending method overcomes difficulties in producing unusual MWDs and offers a general synthetic strategy for studying structure-property relationships of polymers.
Article
Chemistry, Multidisciplinary
Masatoshi Tosaka, Hinako Takeuchi, Masato Kibune, Tianxiang Tong, Nanyi Zhu, Shigeru Yamago
Summary: Stochastic simulation of the formation process of hyperbranched polymers (HBPs) using a branch-inducing monomer, evolmer, revealed that the observed dispersities (Ds) were due to the distribution of the number of branches instead of undesired side reactions. The simulation also showed that the branch structures were well controlled and the majority of HBPs had structures close to the ideal one. Furthermore, the simulation suggested a slight dependence of branch density on molecular weight, which was experimentally confirmed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Multidisciplinary Sciences
Lei Wang, Yupo Xu, Quan Zuo, Haojie Dai, Lei Huang, Meng Zhang, Yongli Zheng, Chunyang Yu, Shaodong Zhang, Yongfeng Zhou
Summary: The authors have developed a novel decolorable, metal-free and visible light-controlled living cationic polymerization system. This system exhibits predictable molar mass, low dispersity and sequential polymerization capability, and shows the longest off period of 36 hours. Furthermore, the residual photocatalyst can be easily deactivated and decolored.
NATURE COMMUNICATIONS
(2022)
Article
Polymer Science
Ning Li, Xiang-Cheng Pan
Summary: This article introduces a new method - oxygen initiation, which can directly transform molecular oxygen into the initiating carbon radical in CRP, improving oxygen tolerance. RAFT polymerization initiated by oxygen allows for control of the polymerization spatiotemporally under ambient conditions, leading to the synthesis of ultra-high molecular weight polymers.
CHINESE JOURNAL OF POLYMER SCIENCE
(2021)
Article
Polymer Science
Glenn K. K. Clothier, Thiago R. Guimaraes, Graeme Moad, Per B. Zetterlund
Summary: The study investigates the synthesis of multiblock copolymers using seeded RAFT emulsion polymerization and how experimental conditions affect the control over molecular weight distribution (MWD). It was found that high T-g values of polymer particles lead to reduced control over MWD via the RAFT mechanism.
Article
Chemistry, Multidisciplinary
Sergey A. Dergunov
Summary: Fast and well-controlled photoinduced atom transfer radical polymerization in an organized bilayer system under visible light leads to polymers with predetermined molecular weight and low dispersity. The mobility and orientation of monomers with respect to the bilayer and the photoredox catalyst localized in the interstitial layer are crucial for the success of the process.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Yu-Xi Wang, Yang Li, Shi-Hui Qiao, Jing Kang, Zhi-Li Shen, Ning-Ning Zhang, Zesheng An, Xiaosong Wang, Kun Liu
Summary: A staged-thermal-initiation RAFT polymerization method is reported for the synthesis of polymers with high thiol end-group fidelity, which show high efficiencies for grafting to various gold nanoparticles (GNPs). Experimental proof shows that the decrease of end-group fidelity with molecular weight is caused by the gradual decomposition of the initiator. The positive correlation between end-group fidelity of polymers and grafting-to efficiency is illustrated through grafting-to assays for various GNPs.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Fuqiang Lan, Junle Zhang, Yuying Li, Yaxuan Shi, Yuancheng Zhang, Ge Shi, Xiaomeng Zhang, Zhe Cui, Peng Fu, Minying Liu, Xiaoguang Qiao, Yanjie He, Wenjie Zhang, Xinchang Pang
Summary: Highly ordered TiO2 nanotube arrays (TNTAs) and their heterostructure nanocomposites were used as photocatalysts for efficient broadband photoinduced controlled radical polymerization (photoCRP). The combination of electron transfer acceleration from TNTAs' structure and the localized surface plasmon resonance (LSPR) effect with the formation of Schottky barrier via Au nanoparticle modification enabled efficient UV-visible light responsive photoCRP. The resulting polymers exhibited high conversion, living chain-ends, tightly regulated molecular weights, and excellent temporal control properties.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Philipp Gerdt, Armido Studer
Summary: A method has been developed for the synthesis of functionalized alternating copolymers by reversible deactivation radical polymerization, allowing for the generation of a small library of novel alternating terpolymers with diverse functionalities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Kyoungmun Lee, Hyun-Ro Lee, Young Hun Kim, Jaemin Park, Suchan Cho, Sheng Li, Myungeun Seo, Siyoung Q. Choi
Summary: This study demonstrated the continuous generation of hydroxyl radicals in oil-confined aqueous microdroplets, enabling the synthesis of polymers at high reactant concentrations. The transport of hydroxyl radicals also facilitated polymerization reactions in the continuous oil phase. This interfacial phenomenon was successfully applied to the chain extension of polymers.
ACS CENTRAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Shuai Zhang, Yongjin Wang, Hanchu Huang, Derong Cao
Summary: In this article, a novel strategy for controlling the radical ring-opening polymerization of macrocyclic allylic sulfides using reversible addition-fragmentation chain transfer (RAFT) agents was reported. The success of this strategy relies on the desulfurization of the propagating thiyl radical with isocyanide to generate a stabilized alkyl radical for reversible control. The systematic optimization of reaction conditions enables good control over the polymerization and the formation of polymers with well-defined architectures, including radical block copolymerization and the incorporation of sequence-defined segments.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Jacob J. Lessard, Kevin A. Stewart, Brent S. Sumerlin
Summary: Dynamic networks combine the durability of thermosets with the adaptability and recyclability of thermoplastics. By tuning the molecular weight and chain-length distribution of the polymers, it is possible to actively tailor the flow behavior and viscoelastic properties of the resulting networks.
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
Rhys W. Hughes, Megan E. Lott, Jared I. Bowman, Brent S. Sumerlin
Summary: This study reveals that the rates and molecular weight control of photo-iniferter polymerizations heavily rely on the electronic excitation of the iniferter. Enhanced polymerization rates and control were observed when targeting the n-* pi* transition of the iniferter. The increased rate of C-S photolysis was confirmed to be the reason for the disparities in polymerization rates.
Review
Nanoscience & Nanotechnology
Kevin A. Stewart, Daniel P. DeLellis, Jacob J. Lessard, John F. Rynk, Brent S. Sumerlin
Summary: Thermoset materials sacrifice recyclability and reshapeability for increased chemical and mechanical robustness. However, the static connectivity of thermosets has been replaced with dynamic cross-links in covalent adaptable networks (CANs), which allows for damage repair and reshaping. Hybrid inorganic-organic enaminone vitrimers with high weight percent of polyhedral oligomeric silsesquioxane (POSS) derivatives were synthesized, showing tunability, shapeability, predictable glass transition temperatures, thermal stability, and retention of preordained shape following decomposition. These materials have potential applications in heat-shielding materials (HSMs) with complex detailing.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Angie B. Korpusik, Alafate Adili, Kamal Bhatt, Jacqueline E. Anatot, Daniel Seidel, Brent S. Sumerlin
Summary: We have developed a convenient method for degrading polyacrylate homopolymers. Carboxylic acids are introduced into the polymer backbone through hydrolysis of the ester side chains, and then converted into alkenes and oxidatively cleaved in a one-pot sequential procedure. This method allows the robustness and properties of polyacrylates to be maintained during their usable lifetime. The degree of degradation can be tuned by varying the carboxylic acid content of the polymers. This method is compatible with a wide range of polymers prepared from vinyl monomers through copolymerization with different monomers including acrylates, acrylamides, and styrenics.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Polymer Science
Digvijayee Pal, Debabrata Konar, Brent S. Sumerlin
Summary: Poly(vinyl ketones) (PVKs) have been extensively studied for their unique photochemistry and photodegradation properties under ultraviolet (UV) light. PVKs rapidly undergo photodegradation through Norrish type I or Norrish type II reaction mechanisms, and the side-chain carbonyl moieties can be easily modified by nucleophilic addition reactions. These properties make PVKs versatile scaffolds for generating functional materials. This review provides an overview of synthetic routes to access well-defined PVKs, their photochemistry and photo-degradation pathways, as well as recent and potential applications of these photodegradable materials.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Cabell B. Eades, Joanna Korpanty, John B. Garrison, Georg M. Scheutz, Sofia L. Goodrich, Nathan C. Gianneschi, Brent S. Sumerlin
Summary: We present a dual-responsive block copolymer system that can control the size and morphology of self-assembled nanostructures through pH-dependent cloud point (Tcp). By incorporating a pH- and temperature-responsive monomer, 2-(dimethylamino)ethyl methacrylate (DMAEMA), in the nanoparticle corona, the relative hydrophilic/hydrophobic block volumes can be controlled. Varying the pH, temperature, and content of DMAEMA, we successfully generated micelles, worms, and vesicles from a single block copolymer composition.
Article
Multidisciplinary Sciences
Senthilkumar Duraivel, Dimitri Laurent, Didier A. Rajon, Georg M. Scheutz, Abhishek M. Shetty, Brent S. Sumerlin, Scott A. Banks, Frank J. Bova, Thomas E. Angelini
Summary: We have developed a silicone 3D printing technique that utilizes a support material to create precise and strong structures. This technique allows for the use of established silicone formulations to fabricate complex structures and features as small as 8 micrometers in diameter.
Article
Polymer Science
Georg M. Scheutz, Jared I. Bowman, Swagata Mondal, Julia Y. Rho, John B. Garrison, Joanna Korpanty, Nathan C. Gianneschi, Brent S. Sumerlin
Summary: Polymerization-induced self-assembly (PISA) can be used as a synthetic tool to direct gradient copolymer synthesis by leveraging hydrophobicity-induced reaction selectivity and rate acceleration associated with polymer compartmentalization during PISA.
Article
Nanoscience & Nanotechnology
Lily E. Diodati, Sitong Liu, Carlos M. Rinaldi-Ramos, Brent S. Sumerlin
Summary: Covalent adaptable networks (CANs) combine the stability of thermosets with the reprocessability of thermoplastics through the incorporation of dynamic crosslinks. In this study, we incorporated Fe3O4 nanoparticles as fillers in a vinylogous urethane vitrimer to facilitate induction heating processing. Despite the common decrease in flow rate and reprocessing difficulty caused by the inclusion of inorganic fillers, the presence of Fe3O4 nanoparticles did not affect the flow behavior of the vitrimer, possibly due to the nanoparticles' catalytic effect on dynamic exchange chemistry. Two methods of incorporating the nanoparticles were employed, and the vitrimers with covalently crosslinked nanoparticles exhibited a shorter relaxation time compared to those with blended nanoparticles. The magnetic character of the Fe3O4 nanoparticles enabled self-healing of the vitrimer composite materials during induction heating.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Jared I. Bowman, Cabell B. Eades, Maria A. Vratsanos, Nathan C. Gianneschi, Brent S. Sumerlin
Summary: Polymerization-induced self-assembly (PISA) is a powerful technique for producing block copolymer nanostructures, and ultrafast photoiniferter PISA can be used to quickly create various nanostructures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Parker T. Boeck, Joji Tanaka, Wei You, Brent S. Sumerlin, Adam S. Veige
Summary: The successful A(2) + B-2 RAFT step-growth polymerization of bis-acrylamides was demonstrated using a bifunctional trithiocarbonate chain transfer agent as the comonomer. Surprisingly, the typical homopropagation of acrylamides leading to branching and crosslinking was not observed. Additionally, the synthesized poly(acrylamides) can be degraded by simply adding excess ethanolamine or PBu3.
Article
Materials Science, Multidisciplinary
Lily E. Diodati, Alexander J. Wong, Megan E. Lott, Anna G. Carter, Brent S. Sumerlin
Summary: The molecular weight of ultrahigh molecular weight polyacrylates has a significant impact on their mechanical properties, as highlighted in this study. By increasing the molecular weight, the mechanical and thermal properties of poly(methyl acrylate) were dramatically improved. This finding led to the successful enhancement of cohesive strength and thermal stability in pressure-sensitive adhesives. The potential of ultrahigh molecular weight polyacrylates in the development of robust materials is demonstrated.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sung-Min Hyun, Arkadios Marathianos, Parker T. Boeck, Ion Ghiviriga, Daniel W. Lester, Brent S. Sumerlin, Adam S. Veige
Summary: This article discusses the influence of solvents on the tacticity of cyclic polynorbornene synthesis, revealing that toluene produces cis, syndiotactic c-PNB while THF produces cis, syn/iso c-PNB.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Emmanuelle Schue, Dillon R. L. Rickertsen, Angie B. Korpusik, Alafate Adili, Daniel Seidel, Brent S. Sumerlin
Summary: We developed a straightforward approach to synthesizing alternating styrene-propylene and styrene-ethylene copolymers by combining radical polymerizations and powerful post-polymerization modification reactions. This method demonstrates wide applicability for functional polymer synthesis.
