Thermoplastic polyurethane elastomers enjoy an exceptionally wide range of applications due to their remarkable versatility. These block co-polymers are used here as an example of a structurally inhomogeneous composite containing nano-scale gradients, whose internal strain differs depending on the length scale of consideration. Here we present a combined experimental and modelling approach to the hierarchical characterization of block co-polymer deformation. Synchrotron-based small- and wide-angle X-ray scattering and radiography are used for strain evaluation across the scales. Transmission electron microscopy image-based finite element modelling and fast Fourier transform analysis are used to develop a multi-phase numerical model that achieves agreement with the combined experimental data using a minimal number of adjustable structural parameters. The results highlight the importance of fuzzy interfaces, that is, regions of nanometre-scale structure and property gradients, in determining the mechanical properties of hierarchical composites across the scales.
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http://dx.doi.org/10.1038/ncomms7583 | DOI Listing |
Materials (Basel)
December 2024
Institute of Joining and Welding, Technical University of Braunschweig, 38106 Braunschweig, Germany.
In accordance with German guideline ZTV-ING Part 4, full-locked coil ropes are provided with a three-layer corrosion protection coating based on epoxy resin and polyurethane, which must be renewed regularly. An alternative method is to use a coating of high-density polyethylene (HDPE), which is extruded onto the rope. In this article, the mechanical behavior of the thermoplastic material is studied, taking into account various accelerated aging processes, which are derived from the climatic boundary conditions of a real bridge structure and implemented in tests.
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December 2024
School of Transportation and Logistics Engineering, Wuhan University of Technology, Wuhan 430063, China.
The water-lubricated bearing plays a crucial role in the ship propulsion system, significantly impacting vessel safety. However, under the harsh working conditions of low-speed and heavy-load, the lubrication state of water-lubricated bearings is usually poor, leading to serious friction and wear. To improve the tribological performance of composites and reduce friction, three short fibers (ultra-high-molecular-weight polyethylene fibers, basalt fibers, and bamboo fibers) with the same mass fraction (5%) were added into the melted thermoplastic polyurethane (TPU).
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December 2024
Department of Mechanical Engineering, University of Nevada, Las Vegas, NV 89154, USA.
Chem Sci
December 2024
LAQV@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto Rua do Campo Alegre s/n 4169-007 Porto Portugal
The recently discovered metagenomic urethanases UMG-SP1, UMG-SP2, and UMG-SP3 have emerged as promising tools to establish a bio-based recycling approach for polyurethane (PU) waste. These enzymes are capable of hydrolyzing urethane bonds in low molecular weight dicarbamates as well as in thermoplastic PU and the amide bond in polyamide employing a Ser-Ser -Lys triad for catalysis, similar to members of the amidase signature protein superfamily. Understanding the catalytic mechanism of these urethanases is crucial for enhancing their enzymatic activity and improving PU bio-recycling processes.
View Article and Find Full Text PDFACS Nano
January 2025
College of Materials and Chemistry & Chemical Engineering, Nuclear Technology Key Laboratory of Earth Science, Chengdu University of Technology, Chengdu 610059, China.
The precise patterning of elastic semiconductors holds encouraging prospects for unlocking functionalities and broadening the scope of optoelectronic applications. Here, perovskite films with notable elasticity capable of stretching over 250% are successfully fabricated by using a continuous-wave (CW) laser-patterning technique. Under CW laser irradiation, perovskite nanoparticles (NPs) undergo meticulous crystallization within the thermoplastic polyurethane (TPU) matrix, which yields the capability of an unparalleled stretch behavior.
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