Article
Polymer Science
Liuyong Zhu, Jingqing Li, Hongfei Li, Binyuan Liu, Jizhong Chen, Shichun Jiang
Summary: The topology of polymer chains, including entanglement loops, tie molecules, and end groups, plays a crucial role in polymer crystallization. In this study, low molecular weight poly(epsilon-caprolactone)s (PCL) with different end groups (phenyl, naphthyl, and anthracenyl) were synthesized to avoid entanglement. The crystallization behavior of these PCLs was investigated using various techniques, and the rheology property of the PCL melts was characterized. The results showed that the size of the end groups inversely influenced the spherulite growth rate and crystallization half-time, with the largest end group leading to the slowest growth rate and longest half-time. However, the effect of naphthyl and phenyl on the crystallization rate was similar. Rheology results revealed that naphthyl modified PCL had lower viscosity due to its compatibility with PCL. Interestingly, regardless of the end groups, the spherulite growth rate and crystallization half-time showed the same behavior when plotted against supercooling, suggesting that the conformation changes during crystallization were consistent for polymer chains with different end groups. Moreover, simultaneous SAXS/WAXS investigations on the heating samples with different end groups after isothermal crystallization showed doubled lamellar thickness during melting, possibly indicating a transition from folded chains to extended chains in the dynamic favored metastable structures.
Article
Polymer Science
Yuanyuan Dou, Han Wu, Li Zhang, Zhenbo Ning, Ni Jiang, Zhihua Gan
Summary: Three types of spherulitic morphologies, including conventional ring-banded spherulites, special spherulites with a curve-like morphology, and composite spherulites, were found in PCL-b-PA6-b-PCL due to the wide crystallization temperature range of chemically jointed PA6 blocks. The formation conditions, internal factors, and lamellar orientation and assembly of different spherulites were studied in detail. The appearance of unusual spherulitic morphology may result from different internal stress induced by chemically jointed PA6 blocks under diverse crystallization conditions.
Article
Chemistry, Multidisciplinary
Liuyong Zhu, Jingqing Li, Hongfei Li, Binyuan Liu, Jizhong Chen, Shichun Jiang
Summary: The entanglement of cyclic polymers was investigated in this study. Cyclic poly(epsilon-caprolactone)s (PCLs) with different molecular weights were synthesized without linear precursors. The crystallization and melting behaviors of unconcatenated and unknotted cyclic PCLs were studied using DSC, POM, and X-ray. The results showed that the crystallization rate and spherulite growth rate of cyclic PCLs were influenced by their molecular weights. The combination of ring topology and entanglement led to maximum crystallization rate and minimum lamellar thickness at a medium molecular weight.
Article
Polymer Science
Ainhoa Fernandez-Tena, Ricardo Arpad Perez-Camargo, Olivier Coulembier, Leire Sangroniz, Nora Aranburu, Gonzalo Guerrica-Echevarria, Guoming Liu, Dujin Wang, Dario Cavallo, Alejandro J. Mueller
Summary: The role of molecular weight in the crystallization and melt memory of PCL was investigated. Different samples with a range of molecular weights were analyzed using various characterization techniques. The results showed that certain parameters, such as melting temperature and equilibrium melting temperature, saturated at a particular molecular weight, while others, such as crystallization temperature and degree of crystallinity, exhibited a bell-shaped behavior. SAXS analysis revealed different chain conformations at different molecular weights, and morphological studies showed different crystalline structures. The melt memory effect of PCL increased with molecular weight due to increased entanglements and chain folding. SSA experiments indicated that molecular weight did not affect intermolecular interactions.
Article
Polymer Science
Hanieh Aghaiee Ranjbar, Mohammad Nourany, Majid Mollavali, Fatemeh Noormohammadi, Safora Jafari
Summary: This study synthesized in situ polyurethane bionanocomposites using different contents of cellulose nanocrystals as cross-linking agents to control phase separation, and evaluated the effect of grafted cellulose nanocrystals on shape fixity and recovery of the specimens. The research also revealed the influence of surface hydrophobicity on cell adhesion behavior, showing great potential for tissue engineering applications.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2021)
Article
Materials Science, Multidisciplinary
Hongwen Sun, Jiachun Feng
Summary: The study investigated the nucleation effect of the synthesized nucleating agent Ca-HHPA on PCL by different thermal treatments. The results showed that Ca-HHPA80-200 had a significantly improved nucleation efficiency compared to Ca-HHPA80 under similar dosages.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Polymer Science
Xiang Liu, Wei Yu
Summary: The study demonstrates that weak shear can slow down the crystallization rate of polymer melts, weaken the melt memory effect of crystallization, and accelerate chain re-entanglements.
Article
Materials Science, Biomaterials
Wei Fan, Randall E. Youngman, Xiangting Ren, Donghong Yu, Morten M. Smedskjaer
Summary: The study found that self-healing hybrid systems with interpenetrating network of organic and inorganic components can resist cyclic loading and heal induced damages. By controlling the degree of silica-crosslinking and organic/inorganic ratio, thermal stabilities, densities, Young's modulus, and hardness of the material can be regulated. This research could lead to the design of tailored functional hybrid materials with potential applications in areas like soft robotics and bone regeneration.
JOURNAL OF MATERIALS CHEMISTRY B
(2021)
Article
Chemistry, Physical
Liuyong Zhu, Jingqing Li, Hongfei Li, Binyuan Liu, Jizhong Chen, Shichun Jiang
Summary: The Rouse model is suitable for exploring the linear dynamics of unentangled polymers and provides a basic framework for understanding polymer chain dynamics. In this study, cyclic poly(& epsilon;-caprolactone)s (c-PCLs) with bi-anthracenyl group pendants were synthesized to investigate the chain dynamics and crystallization behavior. The results showed double endothermic peaks in the DSC curves of c-PCLs after isothermal crystallization, indicating the role of pendants in the reorganization of metastable structures. Banded spherulites of unentangled c-PCLs were observed for the first time, suggesting a mismatch between chain dynamics and crystallization kinetics.
Article
Polymer Science
Timur Mukhametzyanov, Juern W. P. Schmelzer, Egor Yarko, Albert Abdullin, Marat Ziganshin, Igor Sedov, Christoph Schick
Summary: Experimental study on the crystal nucleation and overall crystallization kinetics of cross-linked poly(epsilon-caprolactone) using fast scanning calorimetry revealed that the influences of cross-linking degree differ. Increasing cross-linking leads to longer nucleation and crystallization half-times, while the temperatures of maximum nucleation and overall crystallization rates remain unchanged. The average distance between cross-links in the polymer was found to be smaller than the estimated lamellae thickness, suggesting the inclusion of cross-links in the crystalline phase.
Article
Polymer Science
Shanshan Li, Mehedi H. Rizvi, Brian B. Lynch, Joseph B. Tracy, Ericka Ford
Summary: Flexible cPPHA/PCL fibers have been successfully fabricated by incorporating PCL into cPPHA using a modified wet spinning method, showing fast transience in response to daylight. These fibers have potential applications in wearable electronics, intelligent textiles, and zero waste packaging where modest mechanical performance and fast transience are desired.
MACROMOLECULAR RAPID COMMUNICATIONS
(2021)
Article
Polymer Science
Nicoletta Inverardi, Maurizio Toselli, Giulia Scalet, Massimo Messori, Ferdinando Auricchio, Stefano Pandini
Summary: In this study, amphiphilic materials with proper shape memory effects were prepared by photo-cross-linking. These materials can cyclically change their shape between two configurations under certain thermal/mechanical conditions, showing potential applications in the biomedical field and soft robotics.
Article
Polymer Science
Charalampos Pronoitis, Minna Hakkarainen, Karin Odelius
Summary: By rational design of the microstructure of PHUs and utilizing solubility as an enabling tool, complex architectures can be realized with benign reagents and atom-economical reactions, without harsh reaction conditions and solvents. This approach expands the synthetic intricacy for PHUs and could potentially broaden their applications and opportunities in the future.
Article
Polymer Science
Xiaodong Li, Meishuai Zou, Lisha Lei, Longhao Xi
Summary: The study found that the non-isothermal crystallization behaviors of PEG and PEG-PCL vary under different cooling rates, with the cooling rate significantly affecting the crystallization of PEG-PCL.
Article
Materials Science, Multidisciplinary
Katalee Jariyavidyanont, Rui Zhang, Qiang Yu, Andreas Janke, Thomas Thurn-Albrecht, Christoph Schick, Rene Androsch
Summary: The crystallization behavior of PCL was studied using fast cooling and slow heating methods. It was found that crystallization at low temperature resulted in irregular crystal growth, with short lamellae or particle-like structures observed. Slow heating prevented the formation of perfect crystal structures.
Article
Biochemistry & Molecular Biology
Xiaoyang Qiu, Zeke Li, Yanggui Wu, Wolfgang H. Binder, Senbin Chen, Jintao Zhu
Summary: Chemodynamic therapy (CDT) combined with chemotherapy (CT) using core-coordinated amphiphilic polymer nanoparticles shows promising potential for enhancing antitumor outcomes. The self-assembled nanoparticles effectively deplete glutathione (GSH) through the reduction of Cu(II), resulting in the generation of center dot OH and promoting CDT. The release of chemotherapy drug chlorambucil (CBL) through disulfide bond cleavage contributes to further GSH decline, leading to a combined CDT/CT approach.
Article
Polymer Science
Kshitij Sanjay Shinde, Philipp Michael, Daniel Fuhrmann, Wolfgang H. Binder
Summary: This article reports on the mechanochemical activation of metal-organic frameworks (MOFs) and demonstrates the potential for stress detection in polymer networks embedded with MOFs.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Correction
Biochemistry & Molecular Biology
Xiaoyang Qiu, Zeke Li, Yanggui Wu, Wolfgang H. Binder, Senbin Chen, Jintao Zhu
Article
Chemistry, Physical
Mostafa Ahmadi, Lucas Loeser, Gerard Pareras, Albert Poater, Kay Saalwaechter, Sebastian Seiffert
Summary: The properties of polymer networks are influenced by the presence of connectivity defects like loops and dangling ends. Transient polymer networks based on metallo-supramolecular polymer networks and hindrance can self-sort to develop networks with fewer defects. By using heteroleptic complexes and adjusting the coordination geometry preference, we can control the self-sorting process and reduce the formation of primary loops and dangling ends. Our results show that copper(I) can adopt the desired geometry requirements and create a network with the least number of defects.
CHEMISTRY OF MATERIALS
(2023)
Review
Polymer Science
Kay Saalwaechter, Thomas Thurn-Albrecht, Wolfgang Paul
Summary: This review focuses on recent developments in elucidating the formation of semicrystalline structures in bulk polymer melts, with an emphasis on less systematically studied factors. These factors include the influence of chain motion through the crystallites on the final crystallite thickness, and the effects of entanglements on crystal growth and crystallinity reduction. Theoretical interest lies in understanding the thermodynamic driving forces of polymer crystallization, providing a theoretical background for determining resulting structures in experiments based on kinetic limitations.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Article
Polymer Science
Qiang Yu, Afiq Anuar, Albrecht Petzold, Jens Balko, Kay Saalwaechter, Thomas Thurn-Albrecht
Summary: A detailed analysis of polybutylene succinate (PBS), a biodegradable polyester, was conducted using nuclear magnetic resonance (NMR) and small-angle X-ray scattering. It was found that PBS has a high crystallinity and a typical morphology of lamellar crystals with a broad thickness distribution of the amorphous interlayers. The mechanical properties of PBS were also found to be enhanced by additional insertion crystallization during cooling.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Article
Polymer Science
Oleksandr Dolynchuk, Thomas Thurn-Albrecht
Summary: This study reports recent progress in the theoretical and experimental investigation of interface-induced crystallization in polymers. Through a combination of various microscopy and scattering techniques, supported by theoretical analysis, a detailed picture of the two different phenomena of interface-induced crystallization in polymers is achieved.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Review
Polymer Science
Anja Marinow, Zviadi Katcharava, Wolfgang H. H. Binder
Summary: The integration of self-healing polymer materials into advanced lithium batteries shows promise in improving battery performance and reliability. These materials can repair damage to the electrolyte, prevent electrode cracking and pulverization, and stabilize the solid electrolyte interface (SEI), leading to longer battery lifetimes and addressing financial and safety concerns.
Article
Chemistry, Multidisciplinary
Matthias Rohmer, Stefan G. Ebbinghaus, Karsten Busse, Julian Radicke, Joerg Kressler, Wolfgang H. Binder
Summary: A crystal-based living topochemical ring-opening polymerization method was reported for achiral amino-acid N-carboxyanhydrides (NCAs), allowing the synthesis of polymers with higher chain length and purities at mild conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Pharmacology & Pharmacy
E. Lehner, C. Honeder, W. Knolle, W. Binder, J. Scheffler, S. K. Plontke, A. Liebau, K. Mader
Summary: There is a growing need for new drug delivery systems to treat inner ear disorders. In this study, biodegradable implants loaded with triamcinolone were developed using poly(lactic-co-glycolic acid) (PLGA) and polyethylene glycol-poly(lactic-co-glycolic acid) (PEG-PLGA) through hot-melt extrusion. The implants showed improved mechanical stability and controlled drug release over three months. Mathematical simulations of the in vitro release kinetics demonstrated the potential of the developed formulation for complete distribution of triamcinolone in the inner ear.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2023)
Editorial Material
Polymer Science
Frank Cichos, Thomas Thurn-Albrecht
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Article
Polymer Science
Kshitij Sanjay Shinde, Philipp Michael, Wolfgang H. Binder
Summary: A novel thermoplastic polyurethane material embedded with a mechanochemically triggered metal-organic framework (MOF) is reported. The MOF can detect stress distribution by fluorescence detection, acting as a stress sensor.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Article
Polymer Science
Chenming Li, Rajesh Bhandary, Anja Marinow, Stephanie Bachmann, Ann-Christin Poeppler, Wolfgang H. Binder
Summary: This study investigates the influence of an ionic liquid environment on the stability of ureidopyrimidinone hydrogen bonds. The results show that while the hydrogen bonds are sensitive to high temperatures, they remain highly stable in the presence of the ionic liquid.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Yue Cai, Wolfgang H. Binder
Summary: Crosslinking chemistries play a crucial role in polymer modification, particularly when triggered by external stimuli. In this study, enediyne (EDY) is used as a functional entity to induce crosslinking in polyurethanes (PU) through Bergman cyclization (BC). The BC is activated by heating, compression, or stretching, and leads to enhanced properties in the material. Experimental results show that a 7-day compression at room temperature results in approximately 69% BC activation, and after 25 stretching cycles, the tensile strength increases by 62%. This BC phenomenon is further confirmed by differential scanning calorimetry and IR spectroscopy.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Zefan Wang, Mareen Schaller, Albrecht Petzold, Kay Saalwaechter, Thomas Thurn-Albrecht
Summary: Crystallization of polymers from entangled melts leads to the formation of semicrystalline materials with alternating crystalline and amorphous layers. While the factors controlling the thickness of the crystalline layers are well studied, the thickness of the amorphous layers lacks quantitative understanding. This study investigates the effect of entanglements on the semicrystalline morphology using model blends with reduced entanglement density, revealing a reduced thickness of the amorphous layers without significantly affecting the crystal thickness. A simple yet quantitative model is proposed to explain the observed behavior.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
