Article
Polymer Science
Lea-Sophie Hornberger, Philipp Weingarten, Pia L. Lange, Thomas Schleid, Friederike Adams
Summary: This study reports the use of amino-alkoxy-bis(phenolate) yttrium amido and alkoxide catalysts for controlled metal-catalyzed ring-opening polymerization (ROP) of w-pentadecalactone (PDL). By controlling the reaction temperature and using a chain transfer agent, polymers with high molecular weight can be obtained. Additionally, successful synthesis of block copolymers with different block length and molecular weight was achieved, and the preservation of crystallinity in the block copolymers was confirmed.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Rami Hador, Michael Shuster, Vincenzo Venditto, Moshe Kol
Summary: This study proposes a new approach to tolerate stereoerrors in the polymer by crowding them in a stereogradient copolymer. A zirconium complex of an amine tris(phenolate) ligand is used as a catalyst for the ring opening polymerization of meso-lactide at room temperature, and stereogradient copolymers are formed in the polymerization of mixtures of meso-lactide/L-lactide at 180 degrees C. These stereogradient copolymers exhibit enhanced crystallinities compared to stereorandom copolymers obtained with tin octanoate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Mohamed Samir Zaky, Gilles Guichard, Daniel Taton
Summary: This study demonstrates for the first time that an initiator containing a silyl ketene acetal (SKA) group can be used to control the ring-opening polymerization (ROP) of racemic lactide (rac-LA) in the presence of an organic base. This sequential addition strategy expands the scope of organic catalysis in macromolecular engineering of block copolymers involving different propagating species.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Materials Science, Composites
Hossein Ebrahimi, Farhad Sharif, Ahmad Ramazani SA
Summary: The synthesis of nanocomposites through in situ grafting polymerization in the presence of modified titanium dioxide nanoparticles has successfully produced copolymers with different structures, among which the nanocomposite with a LLA/CL mass ratio of 70/30 exhibits the best mechanical properties.
POLYMER COMPOSITES
(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
Hans R. Kricheldorf, Steffen M. Weidner, Felix Scheliga
Summary: Alcohol-initiated ring-opening polymerizations of L-Lactide were conducted, and it was found that caprylate exhibited the highest catalytic activity among the three catalysts tested. Increasing the LA/Cat ratio resulted in higher fractions of cyclic polymers.
JOURNAL OF POLYMER SCIENCE
(2022)
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
Polymer Science
Steffen M. Weidner, Andreas Meyer, Hans R. Kricheldorf
Summary: L-lactide was polymerized in toluene using tin(II) 2-ethylhexanoate as the catalyst. The crystalline properties of the resulting polyLAs were studied under different concentrations, reaction times, and temperatures. It was found that the presence of solvent promoted cyclization, leading to the formation of cyclic polylactides. A new hypothesis for the crystal growth of cyclic polyLAs was proposed.
Article
Polymer Science
Robert Mundil, Alexander Zhigunov, Mariusz Uchman
Summary: In this study, we synthesized and self-assembled mPEG-block-PDL-block-PMMA triblock terpolymers using a metal-free catalytic system, which showed better polymerization control compared to sequential copolymerization. The blocks were found to be incompatible, leading to their self-assembly into multicompartment micelles in water.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Polymer Science
Moritz Meier-Merziger, Marcel Fickenscher, Frank Hartmann, Bjoern Kuttich, Tobias Kraus, Markus Gallei, Holger Frey
Summary: Bifunctional initiators were used to synthesize complex triblock copolymer structures in carbanionic polymerization. Isoprene was polymerized using 1,3-bis(1-phenylethenyl)benzene (PEB), resulting in a high content of 93% 1,4-PI units. Hydroxyl groups were then introduced simultaneously in the alpha- and omega-position using end-functionalization of the living anionic di-lithiated polyisoprene (PI) chains with 1,2-isopropylidene glyceryl glycidyl ether (IGG) and subsequent acidic deprotection. The resulting hexa-hydroxy functional PI-macroinitiators were used to initiate l-lactide (LLA) polymerization, leading to the formation of super-H-shaped (PLLA)(3)-b-PI-b-(PLLA)(3) triblock structures with narrow molecular weight distributions.
Article
Polymer Science
Shin Inagaki, Tomoya Higashihara
Summary: A novel ABC-type triblock copolymer, consisting of PMMA, P3HT, and PS, was synthesized by the bilateral CuAAC reaction, resulting in a high yield.
Article
Polymer Science
Hans. R. Kricheldorf, Steffen M. Weidner
Summary: Alcohol-initiated ring-opening polymerizations of L-lactide were investigated, with variations in the alcohol nature, LA/initiator ratio, LA/SnOct2 ratio, and time. Neat SnOct2 exhibited catalytic activity in THF and some aromatic solvents, while its activity was strongly reduced in solvents like 1,3-dioxolane, dimethylformamide (DMF), and N-methyl pyrrolidone (NMP). The formation of cyclization was observed at 115°C in toluene but not at 70°C, which was attributed to the reduced mobility of the initially formed linear chains in toluene.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Polymer Science
Shuang Li, Han Lu, Ling Zhu, Meixue Yan, Xiaohui Kang, Yi Luo
Summary: The mechanisms of ring-opening polymerization of L-lactide and trimethylene carbonate using DMAP/Sac as a bifunctional catalyst were investigated using DFT calculations. A new two-component organocatalyst Adenine/Sac was also designed and evaluated for its catalytic performance. The results showed that Adenine/Sac exhibited higher catalytic activity in the ring-opening of L-lactide and trimethylene carbonate.
Article
Chemistry, Multidisciplinary
Xiao Jiang, Na Zhao, Zhibo Li
Summary: A bifunctional H-bonding catalyst SQ-1 and the binary H-bonding catalytic system consisting of squaramides (SQ-2 to SQ-6) and DBU were discovered to efficiently promote the stereoselective ring-opening polymerization (ROP) of rac-lactide at room temperature. The resulting polylactides exhibited controlled molecular weights and high tacticity.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Polymer Science
Hans R. Kricheldorf, Steffen M. Weidner
Summary: The research showed that 2,2'-dihydroxybiphenyl is the most successful cocatalyst for bismuth subsalicylate in ring-opening polymerization of l-lactide, and optimization of reaction time and temperature is crucial for achieving high weight average molecular weights. Additionally, some unusual transesterification reactions were discovered, and triphenylphosphine was found to be an effective catalyst poison.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Physical
Zhibin Wen, Leila Bonnaud, Rosica Mincheva, Philippe Dubois, Jean-Marie Raquez
Summary: This study details the scalable and solventless synthesis of a potential fully biobased resin derived from tyrosol and furfurylamine, showing promising thermal and mechanical properties, making it a candidate material for coating applications.
Article
Polymer Science
Abhijit Venkatesh, Lilian Forsgren, Angelica Avella, Karl Banke, Jan Wahlberg, Fabiola Vilaseca, Giada Lo Re, Antal Boldizar
Summary: Comparison between laboratory-scale and pilot-scale compounding showed that the materials compounded on a pilot scale exhibited higher viscosity, improved mechanical properties, and different morphology. The presence of a relatively strong percolating cellulosic network in the melts and the importance of the interphase region between cellulose and the matrix were highlighted for the mechanical performance of the composites, with thermomechanical pulp providing better reinforcement than cellulose nanocrystals.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Chemistry, Physical
Marius Murariu, Armando Galluzzi, Yoann Paint, Oltea Murariu, Jean-Marie Raquez, Massimiliano Polichetti, Philippe Dubois
Summary: The addition of nanofillers to polylactic acid can improve its properties and achieve specific end-use characteristics. These polymer nanocomposites exhibit strong magnetization properties and are suitable for various applications.
Article
Chemistry, Multidisciplinary
Antoniya Toncheva, Loic Brison, Philippe Dubois, Fouad Laoutid
Summary: This study incorporated recycled tire rubber into polymer matrices using selective laser sintering as 3D printing technology. The morphological characteristics, mechanical properties, and thermal stability of the polymer composites were evaluated to reveal the potential of using recycled tire rubber in additive manufacturing.
APPLIED SCIENCES-BASEL
(2021)
Article
Polymer Science
Hongzhou Xie, Hongxu Meng, Linbo Wu, Bo-Geng Li, Philippe Dubois
Summary: Poly(ethylene 2,5-furandicarboxylate) (PEF) was modified with aliphatic polycarbonate (APC) diols by chain extension/coupling to obtain PEF materials with improved ductility, impact toughness, high strength, modulus, and excellent gas barrier performance.
Article
Polymer Science
Alma Lucia Villela Zumaya, Rosica Mincheva, Jean-Marie Raquez, Fatima Hassouna
Summary: This review provides an overview of the recent advances in developing nanoclusters based on polymeric nanoparticles and/or inorganic NPs, and summarizes the design, fabrication, and properties of noble-metal nanoclusters and hybrid nanoclusters in cancer therapy.
Article
Nanoscience & Nanotechnology
Chiara Magnani, Mina Fazilati, Roland Kadar, Alexander Idstrom, Lars Evenas, Jean -Marie Raquez, Giada Lo Re
Summary: In this study, chitin nanocrystals (ChNCs) were extracted using a waterborne topochemical one-pot acid hydrolysis/Fischer esterification method, and their surfaces were simultaneously decorated with lactate or butyrate moieties. The modified ChNC colloids showed a gel-like phase, disrupting the formation of liquid crystalline clusters. Pickering emulsions prepared from lyophilized nanocrystals demonstrated that the individualization of the modified ChNCs can be regenerated from the dry state.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Physical
Marie Bayart, Marie Dubus, Sebastien Charlon, Halima Kerdjoudj, Nicolas Baleine, Samira Benali, Jean-Marie Raquez, Jeremie Soulestin
Summary: Scaffolds with specific features help cells to attach, proliferate, and differentiate. In this study, PLA and PLA/HA scaffolds were produced and the effect of HA particles on the scaffolds was investigated. The presence of HA induced faster and more complete polymer biodegradation, while PLA scaffolds did not degrade during conditioning.
Article
Polymer Science
Marius Murariu, Yoann Paint, Oltea Murariu, Fouad Laoutid, Philippe Dubois
Summary: This study demonstrates that specifically thermally treated AII made from natural gypsum is highly stable and can be used as a filler in PLA composites, resulting in composites with excellent filler dispersion and stability, improved thermal and mechanical properties, especially stiffness and impact resistance.
Article
Chemistry, Physical
Aicha Amior, Hamid Satha, Fouad Laoutid, Antoniya Toncheva, Philippe Dubois
Summary: Due to their natural availability, renewability, biodegradability, nontoxicity, light weight, and relatively low cost, natural fibers, especially lignocellulosic fibers, are attractive potential substitutes for non-eco-friendly synthetic fibers. In this study, Ziziphus jujuba fibers with low lignin content were used as an alternative renewable resource for the production of cellulosic fibers with suitable characteristics and minimal energy consumption. The efficient removal of noncellulosic compounds resulted in an increase in crystallinity index and higher surface area of the fibers, making Ziziphus jujuba fibers a suitable sustainable source for the production of cellulosic fibers.
Article
Polymer Science
Marius Murariu, Yoann Paint, Oltea Murariu, Fouad Laoutid, Philippe Dubois
Summary: Polypropylene (PP) filled with CaSO4 beta-anhydrite II (AII) from natural gypsum was studied for high-performance composites. The addition of zinc diacrylate (ZnDA) improved the thermal and mechanical properties of PP-AII composites. The composites also showed improved elastic behavior and heat deflection temperature. Reactive extrusion (REx) on twin-screw extruders was used for large-scale production and performance evaluation.
Article
Polymer Science
Marius Murariu, Yoann Paint, Oltea Murariu, Fouad Laoutid, Philippe Dubois
Summary: This study investigates the toughening effect of tributyl citrate (TBC) on polylactide (PLA) composites. The addition of TBC results in decreased glass transition temperature (T-g) and rigidity, increased ductility and impact resistance. Furthermore, reactive modification with epoxy functional styrene-acrylic oligomers enhances the rheological properties of the composites.
Article
Materials Science, Multidisciplinary
Fouad Laoutid, Maryam Jouyandeh, Oltea Murariu, Henri Vahabi, Mohammad Reza Saeb, Loic Brison, Marius Murariu, Philippe Dubois
Summary: This study investigated the flame-retardant effect of transparent epoxy coating with aluminum hypophosphite nanoparticles on polylactic acid sheets. The addition of these nanoparticles into the epoxy resin accelerated the degradation of the coating, resulting in increased char residue. The presence of the nanoparticles reduced the peak heat release rate significantly, leading to the formation of a homogeneous char layer with a 15 wt.% nanoparticle content. However, further increase in content did not enhance the flame-retardant properties due to the formation of structural cracks in the coating.
Editorial Material
Environmental Sciences
Stijn Everaert, Greet Schoeters, Karel Claes, Jean-Marie Raquez, Bart Buffel, Tamara Vanhaecke, Jonas Moens, Juha Laitinen, Nicolas Van Larebeke, Lode Godderis
Summary: Firefighters are exposed to various chemicals that may lead to health issues. Wearing nitrile butadiene rubber undergloves is a preventive measure against toxic accumulation, although its safety is questioned.
Article
Nanoscience & Nanotechnology
Aleksandar Y. Mehandzhiyski, Emile Engel, Per A. Larsson, Giada Lo Re, Igor V. Zozoulenko
Summary: Cellulose is a promising alternative to synthetic polymers in the development of sustainable and environmentally friendly materials. However, it cannot be melt-processed like many synthetic polymers. Chemical modification, such as dialcohol cellulose, can improve its thermoplasticity. A molecular dynamics study of dialcohol cellulose nanocrystals with different degrees of modification reveals that stress, interfacial stiffness, hydrogen-bond network, and cellulose conformations during mechanical shearing are highly dependent on the degree of modification, water layers, and temperature. Experimental investigation shows that increasing the degree of modification and/or water content makes the melt processing of dialcohol cellulose easier, which aligns with the conclusions from the molecular modeling.
ACS APPLIED BIO MATERIALS
(2022)
