Article
Polymer Science
Huiqun Wang, Sebla Onbulak, Steven Weigand, Frank S. Bates, Marc A. Hillmyer
Summary: The researchers synthesized a series of polyethylene-graft-aPP graft copolymers and found that increasing aPP content led to decreased melting temperatures and glass transition temperatures of PE, as well as decreased crystallinity. Additionally, the linear viscoelastic behavior of the PE-g-aPP graft copolymers exhibited greatly enhanced dynamic modulus and complex viscosity, with the effect increasing as side chain number and/or length increased.
Article
Polymer Science
Chengliang Wang, Xu Zhang, Wei Zhao, Xin Liu, Qingfu Wang, Jingjiang Sun
Summary: This study introduces a novel organo-catalyzed method for the synthesis of hyperbranched aliphatic polycarbonates (HBPCs). The method allows for precise control over the HBPC structure and the introduction of different functional groups. HBPCs have significant potential for biomedical applications.
Article
Materials Science, Multidisciplinary
Anupam Singha Roy, Aby Cheruvathoor Poulose, Aristides Bakandritsos, Rajender S. Varma, Michal Otyepka
Summary: 2D carbon materials like graphene derivatives have been explored as catalysts for biodiesel production due to their exceptional properties, but challenges such as irreversible agglomeration, low bulk density, and poor dispersibility in organic solvents limit their applications as catalysts or heterogeneous catalysts support.
APPLIED MATERIALS TODAY
(2021)
Article
Chemistry, Physical
Zhe-Ran Chang, Si-Si Du, Cui Zhang, Shuang-Hu Chen, Yuan-Zhao Hua, Min-Can Wang, Guang-Jian Mei, Shi-Kun Jia
Summary: An efficient kinetic resolution of racemic trans-2,3-aziridinyl alcohols is achieved through zinc catalyzed ring opening reactions with different amines as nucleophiles. The directing effect of the hydroxyl group and the precise enantiodiscrimination by a dinuclear zinc cooperative catalyst are crucial for high regioselectivity and enantioselectivity. Various enantioenriched vicinal diamines and trans-2,3-aziridinyl alcohols are obtained in good yields with excellent ee values. This study represents the first example of directed enantioselective nucleophilic ring opening reactions of 2,3-aziridinyl alcohols.
Article
Chemistry, Multidisciplinary
Cameron L. Brown, Brandon H. Bowser, Jan Meisner, Tatiana B. Kouznetsova, Stefan Seritan, Todd J. Martinez, Stephen L. Craig
Summary: Woodward and Hoffman once joked about a Maxwell demon that could open a molecule of cyclobutene in a disrotatory fashion. Nearly 40 years later, this concept was realized in the field of covalent polymer mechanochemistry. By combining single-molecule force spectroscopy and computation, the study explored substituent effects in ring-opening reactions of cyclobutene and benzocyclobutene, revealing differences in the forces required for allowed and forbidden reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Yening Xia, Georg M. Scheutz, Charles P. Easterling, Junpeng Zhao, Brent S. Sumerlin
Summary: This study introduces a method for synthesizing well-defined polyacrylamido-b-polyether block copolymers by combining photoiniferter polymerization and organocatalytic ring-opening polymerization. The compatibility between the two polymerization systems is demonstrated, allowing for the tailored synthesis of block copolymers from chemically distinct monomers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Polymer Science
Honggang Mei, Bingjie Zhao, Huaming Wang, Sixun Zheng
Summary: The preparation of crosslinked PDCPD nanoparticles via ROMP-induced self-assembly approach was reported in this communication. The morphology of the obtained nanoparticles varied from spherical, cylindrical to planar depending on the molecular weights of Macro-CTAs, the concentrations of DCPD and the natures of solvents. The ROMPISA method provides a new and efficient approach to prepare crosslinked polymer nanoparticles.
MACROMOLECULAR RAPID COMMUNICATIONS
(2021)
Article
Biochemistry & Molecular Biology
Jieun Choi, Taehwan Yu, Hyun-Joon Ha
Summary: The highly strained three-membered aziridine ring was activated as an aziridinium ion through alkylation of the ring nitrogen and subsequent ring opening with external nucleophiles. This method provides an easy route for synthesizing various N-alkylated amine-containing molecules with the introduction of external nucleophiles at either the alpha or beta position.
Article
Polymer Science
Tehsin Ahmad, Sidra Safdar Durrani, Faiza Jan Iftikhar, Syed Ghulam Musharraf, Muhammad Imran Malik
Summary: Concurrent ring-opening and atom transfer radical polymerization was used to synthesize block copolymers of L-lactide and styrene, requiring careful selection of reaction conditions and reagents. Comprehensive analysis of the synthesized block copolymers revealed uninterrupted simultaneous polymerization of both monomers under applied conditions.
EUROPEAN POLYMER JOURNAL
(2021)
Article
Chemistry, Applied
Kang Fu, Yi Tian, Zongting Zhu, Shixin Fa, Qiuyu Zhang
Summary: Transparent omniphobic coatings have been extensively studied in the past decade to meet increasing application demands. This work proposes a low-cost, eco-friendly, anti-ultraviolet, self-healed, highly transparent, mechanically robust, and chemically resistant fluorinated epoxy coating.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Polymer Science
Tieshuai Zhao, Ben Drain, Gokhan Yilmaz, C. Remzi Becer
Summary: In this study, pentafluoro benzyl bromide was used as a clickable initiator for the cationic ring opening polymerization of poly(2-oxazolines) to synthesize various multiblock copolymers. By combining the para-fluoro-thiol click reaction with terminating agents in a one-pot approach, multiblock copolymers such as PEtOx-mb-PMeOx were successfully prepared. Characterization of the polymers was done using SEC, H-1 NMR, and MALDI-ToF mass spectrometry, and the self-assembly properties were studied using DLS and TEM, which showed nanoparticles with diameters ranging from 184 nm to 250 nm for the PEtOx-mb-PMeOx copolymers.
Article
Polymer Science
Bo Li, Yong-Lu Zhang, Xiao-Feng Zhu, Zhuo-Qun Li, Zi-Hui Li, Hua-Yu Qiu, Guang-Peng Wu
Summary: Poly(p-dioxanone) (PPDO), with the coexistence of ester and ether bonds in the repeating units, has attracted intensive attention in bioengineering and environmental materials. In this study, the ring-opening polymerization (ROP) behavior of p-dioxanone (PDO) using classical organic amidine and guanidine compounds was systematically investigated. Cyclic and linear PPDO homopolymers were efficiently produced and characterized, and triblock copolymers containing poly(e-caprolactone) (PCL) and PPDO were successfully synthesized. The prepared triblock copolymers exhibited tunable flexibility, stabilization, hydrophilicity, and mechanical strength, making them potential thermoplastic materials in biological and tissue engineering areas.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Chemistry, Organic
Xiaoxiao Liaoejoc, Kai Yuan, David Crichejoc
Summary: In this study, two interesting intramolecular displacement reactions involving thiolate sulfur and thiirane sulfur were discovered during the synthesis of 3,5-dithio-glucofuranose. The use of a 5-S,6-O-isopropylidene protecting group successfully solved the intramolecular displacement problem, leading to the synthesis of 3,5-dithio-glucofuranose with a 9% overall yield.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Xuejin Yang, Sean R. Gitter, Allison G. Roessler, Paul M. Zimmerman, Andrew J. Boydston
Summary: Research has found a simple method to control alkene stereochemistry in photoredox mediated metal-free ring-opening metathesis polymerization. Ion-pairing, initiator sterics, and solvation effects each have a profound impact on polynorbornene's stereochemistry. By adjusting reaction conditions, it is possible to control the cis or trans alkene content of PNB.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Lantao Liu, Fangyuan Cheng, Chenxiang Meng, An-An Zhang, Mingliang Zhang, Kai Xu, Naoki Ishida, Masahiro Murakami
Summary: A Pd-catalyzed chemo-, regio-, and enantioselective ring-closing/ring-opening cross coupling reaction has been developed with diverse aryl halide-tethered alkenes and benzocyclobutenols as substrates. This method provides a convenient approach to chiral 2,3-dihydrobenzofurans with excellent enantioselectivities, and has been applied in the concise synthesis of analogues of cannabinoid receptor 2 agonists.