Article
Polymer Science
Fernandez Pelayo, David Blanco, Pedro Fernandez, Javier Gonzalez, Natalia Beltran
Summary: Material extrusion additive manufacturing is used to produce flexible parts for soft robotics, wearables, and flexible electronics applications using thermoplastic polyurethanes. Inner-structure design factors have a significant impact on the viscoelastic relaxation modulus of polyurethane parts, with wall thickness being more influential than other design factors. A viscoelastic material model based on a generalized Maxwell model has been proposed and implemented to accurately predict the mechanical behavior of parts manufactured with material extrusion.
Article
Chemistry, Multidisciplinary
Shuangjian Yu, Siwu Wu, Shifeng Fang, Zhenghai Tang, Liqun Zhang, Baochun Guo
Summary: By introducing dynamic interfacial sulfides, a skeletal network elastomer with continuous reprocessability was successfully constructed. These elastomers exhibit high gel contents, high resilience, low creep, and competitive reinforcement compared to traditional vulcanizates, surpassing commercial thermoplastic vulcanizates (TPVs) materials.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Analytical
Zhi-Min Zhou, Ke Wang, Kai-wen Lin, Yue-Hui Wang, Jing-Ze Li
Summary: The study investigated the influence of TPU masterbatches with different melting points on the distribution of graphene, electrical conductivity, and infrared light thermal properties of graphene-thermoplastic polyurethane (G-TPU) composite films. It was found that the characteristics of TPU had little impact on the electrical conductivity, but significantly affected the thermal conductivity of the composite films.
Article
Engineering, Mechanical
George Rai, Christopher Rahn, Edward Smith, Conor Marr
Summary: This paper introduces additively manufactured beam networks that can isolate vibration with multiple broad bandgaps. The design and prediction of the vibration behavior of different beam isolators are based on an analytical model and validated through experiments, showing ideal band gaps and center frequencies.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Engineering, Environmental
Le Wan, Cong Deng, Hong Chen, Ze-Yong Zhao, Sheng-Chao Huang, Wen-Chao Wei, Ai-Hua Yang, Hai-Bo Zhao, Yu-Zhong Wang
Summary: This review extensively examines the fire safety of TPU, from structural characteristics to flame retardant methods, focusing on additive-type flame retardants and inherently flame-retarded TPU. Various flame retardants and their effects on TPU fire safety, including organic and inorganic monocomponent, modified, hybridized, compound, and nano flame retardants are discussed. Special processes and prospects for flame retardation of TPU without traditional elements or bio-based methods are explored.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Polymer Science
Tamara Calvo-Correas, Miriam Benitez, Izaskun Larraza, Lorena Ugarte, Cristina Pena-Rodriguez, Arantxa Eceiza
Summary: Different ways to valorise discarded TPU ear tags from the livestock sector were studied, including mechanical processing and 3D printing. The results showed that these methods were effective in recycling TPU waste and obtaining materials suitable for printing and electrospinning.
POLYMER DEGRADATION AND STABILITY
(2022)
Article
Thermodynamics
Chuanmei Jiao, Mingxin Li, Xiaoguang Zhang, Xilei Chen
Summary: The study examined the smoke suppression effect of [Glu] H(2)PW(12)O(40) as a smoke suppressant in TPU, revealing significant reductions in smoke production rate, total smoke release, and smoke factor. The [Glu] H(2)PW(12)O(40) also contributed to increased char residue formation and improved thermal stability of TPU at high temperatures, suggesting its potential for smoke suppression in TPU.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Engineering, Mechanical
Yuyang Chai, Xingjian Jing
Summary: This study introduces a novel 3-DOF passive vibration isolation unit that exhibits excellent ultra-low-frequency vibration isolation performance in three directions simultaneously. It features beneficial nonlinear properties and a larger QZS range.
NONLINEAR DYNAMICS
(2022)
Article
Polymer Science
Ying-Chi Huang, Yu-Hsiang Huang, Li-Yun Chen, Chi-An Dai, Shenghong A. Dai, Ying-Hsiao Chen, Chien-Hsin Wu, Ru-Jong Jeng
Summary: This study demonstrated the development of recycling feasibility, monomers reactivity, and the chemical-recycled polymer properties from polycarbonate (PC) waste, resulting in the production of thermoplastic polyurethanes (TPUs) with improved elastomeric properties. The TPUs exhibited a unique phase separation morphology with domain sizes ranging from similar to 10 nm to similar to 25 nm, showing potential for applications in various fields.
Article
Materials Science, Multidisciplinary
Maya Pishvar, Mehrad Amirkhosravi, Ica Manas-Zloczower
Summary: In this study, TPU-PTFE nanocomposites with improved thermomechanical properties were successfully made by fibrillation of micron-sized PTFE particulates inside the TPU matrix. PTFE forms a fibrillary network inside the TPU matrix, which enhances the creep behavior, thermal stability, storage modulus, and reduces the thermal expansion coefficient of the nanocomposites. The glass transition temperature of nanocomposites with 10 wt % PTFE shows two transitions, while a single peak is observed for the neat TPU.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Materials Science, Composites
Chuan Liu, Yongqian Shi, Yuezhan Feng, Xiaoyong You, Wenxi Xie, Yihan Ke, Hengrui Wang, Li Chen, Yuzhong Wang
Summary: This study focused on enhancing the fire safety of thermoplastic polyurethane (TPU) by functionalizing silicon-wrapped ammonium polyphosphate (NSiAPP) with titanium carbide and coupling agent. The resulting TPU composite exhibited improved flame retardancy and smoke suppression, making it a promising strategy for fire resistance improvement in TPU composites.
COMPOSITES COMMUNICATIONS
(2022)
Review
Biochemistry & Molecular Biology
Rafael J. Jimenez Rioboo, Nuria Gontan, Daniel Sanderson, Manuel Desco, Maria Victoria Gomez-Gaviro
Summary: Brillouin spectroscopy has gained significant interest in the biomedical field as a tool to study mechanical properties in biology. It is a contactless, label-free optical approach that enables analysis of tissue mechanical behavior with micrometric resolution, showing promise for clinical diagnosis.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Lijun Zhu, Guilong Wang, Zhaorui Xu, Xinyang Li, Chengming Yang, Guoqun Zhao
Summary: Functionally graded polymer foams with gradient cellular structures are advanced materials that have great potential for applications in energy absorption, electromagnetic interference shielding, and high-elasticity. In this study, a new microcellular foaming strategy was developed to prepare thermoplastic polyurethane (TPU) foams with gradient cellular structures. The structure-gradient TPU foams showed significantly enhanced mechanical performance and elasticity, holding significant promise for broaden applications.
MATERIALS & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Rocio Diaz-Puertas, Enrique Rodriguez-Canas, Melissa Bello-Perez, Marta Fernandez-Oliver, Ricardo Mallavia, Alberto Falco
Summary: The incorporation of ceramic-coated silver nanoparticles (AgNPs) into thermoplastic polyurethane (TPU) plates showed significant antiviral activity against Spring viraemia of carp virus (SVCV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Article
Chemistry, Applied
Haohao Wu, Haopu Xie, Xinxin Tian, Yinglu Sun, Biru Shi, Yan Zhou, Dekun Sheng, Xiangdong Liu, Yuming Yang
Summary: The study successfully prepared a hard and tough thermoplastic polyurethane material PCL-HM with self-healing abilities, which can quickly heal wounds under mild conditions. By using aromatic disulfide bonds as dynamic covalent bonds and incorporating IPDI and HMDI in the hard segment, PCL-HM displays better healing properties compared to other types of TPUs.
PROGRESS IN ORGANIC COATINGS
(2021)
Article
Engineering, Mechanical
Alexandra Aulova, Marko Bek, Leonid Kossovich, Igor Emri
STROJNISKI VESTNIK-JOURNAL OF MECHANICAL ENGINEERING
(2020)
Article
Chemistry, Multidisciplinary
Klementina Pusnik Cresnar, Lidija Fras Zemljic, Lidija Slemenik Perse, Marko Bek
APPLIED SCIENCES-BASEL
(2020)
Article
Materials Science, Characterization & Testing
Alexandra Aulova, Alen Oseli, Marko Bek
Summary: In this study, a multilayer perceptron neural network was used to model the response of high-performance polymer composites to non-standard excitation at different temperatures. The research found that a properly trained neural network can predict polymeric material behavior within the experimental error.
Article
Polymer Science
Klementina Pusnik Cresnar, Marko Bek, Thomas Luxbacher, Mihael Bruncko, Lidija Fras Zemljic
Summary: The surface properties of wood fiber filled polymer composites depend on filler loading, distribution, and orientation in the polymer matrix. Furthermore, the addition of wood fibers affects the surface structure, modulus, and hardness of the composites. Additionally, increasing amounts of wood fibers result in higher hydrophilicity of the composite surface.
Article
Materials Science, Multidisciplinary
Hari Shankar Vadivel, Marko Bek, Urska Sebenik, Lidija Slemenik Pers, Roland Kadar, Nazanin Emami, Mitjan Kalin
Summary: The study investigates the impact of UHMWPE particle size on its performance, as well as the effect of processing. While minor differences in properties among different grades of UHMWPE were observed, they are not sufficient to definitively determine the influence of particle size and processing on the material's properties and performance.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Review
Marine & Freshwater Biology
Ian R. Jenkinson, Elisa Berdalet, Wei-Chun Chin, Michel Denis, Haibing Ding, Jizhou Duan, Florence Elias, Igor Emri, Santosh K. Karn, Zhuo Li, Alenka Malej, Xavier Mari, Laurent Seuront, Jun Sun, Tim Wyatt, Wuchang Zhang, Oliver Wurl
Summary: Plankton and neuston microbes produce organic matter that accumulates on the sea surface, affecting heat and momentum exchange across the sea-air interface and climate change. Studying the ecology and genomics of these microbial communities and their secretions is crucial for incorporating them into climate models.
JOURNAL OF PLANKTON RESEARCH
(2021)
Article
Polymer Science
Marko Bek, Alexandra Aulova, Klementina Pusnik Cresnar, Sebastjan Matkovic, Mitjan Kalin, Lidija Slemenik Perse
Summary: The use of neat and recycled polypropylene matrix materials in wood-polymer composites showed different creep properties. The composites with neat polypropylene matrix exhibited superior creep resistance due to higher crystallinity and better interfacial adhesion caused by the formation of a transcrystalline layer. Compared to composites with recycled polypropylene matrix which does not form a transcrystalline layer, composites with neat polypropylene matrix had a 25% reduction in creep compliance. However, from 20 wt.% on, the creep compliance of composites with recycled polypropylene matrix was comparable or even surpassed that of unfilled neat polypropylene matrix, making it a promising way to promote sustainability.
Article
Chemistry, Multidisciplinary
Silvia D'Auria, Amir Masoud Pourrahimi, Alessia Favero, Peter Neuteboom, Xiangdong Xu, Shuichi Haraguchi, Marko Bek, Roland Kadar, Enrico Dalcanale, Roberta Pinalli, Christian Mueller, Jerome Vachon
Summary: Polyethylene based ionomers have been synthesized with thermo-mechanical and dielectric properties comparable to cross-linked polyethylene (XLPE), making them a promising alternative for high voltage insulation in future HVDC power cables. The ionomers feature similar crystallinity, melting temperature, rubber plateau modulus, and thermal conductivity as XLPE, while remaining melt-processable. Their production process is free of byproducts, resulting in a highly insulating material with low dielectric loss and DC electrical conductivity.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Sajjad Pashazadeh, Alexandra Aulova, Christos K. Georgantopoulos, Marko Bek, Iakovos Vittorias, Ingo F. C. Naue, Manfred Wilhelm, Roland Kadar
Summary: This study investigates the influence of molecular weight and long-chain branching on the types of melt flow extrusion instabilities (MFEI). Four linear low-density polyethylenes (LDPEs) are extruded using a single-screw extruder coupled with an inline optical imaging system. Through the analysis of space-time diagrams constructed with an inline imaging system, three main MFEI types are identified, distinct from those observed in linear and short-chain branched polymers. Higher long-chain branching appears to have a stabilizing effect on the transition sequences.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2023)
Article
Materials Science, Composites
Sajjad Pashazadeh, Reza Ghanbari, Marko Bek, Alexandra Aulova, Tobias Moberg, Anders Brolin, Roland Kadar
Summary: For the first time, surface defects in highly-filled wood polymer composites (WPCs) are mapped using inline optical spectral analysis during single-screw extrusion. The effects of wood fiber content and drying on surface defects dynamics are resolved through space-time inline optical imaging. The study reveals that surface tearing appears at low shear rates and gradually decreases in spectral intensity with increasing shear rates/slip velocities. Increasing shear rates, wood fiber content, and drying have mitigating effects on surface tearing, but it still persists in undried samples even at high shear rates and high wall slip velocities. A regime dominated by bubbles on the extrudate surface is identified at high shear rates and low wood fiber contents in undried WPCs.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Benjamin Podmiljs, Spomenka Kobe, Tomaz Tomas, Marko Bek, Tomaz Kotnik, Lidija Slemenik Pers, Ema Zagar, Boris Saje, Kristina Zuzek, Saso Sturm
Summary: This study describes the fabrication of SrFe12O19-based filaments using PPS as the binder and the subsequent printing of these filaments with a 3D printer. The presence of a magnetic field during printing was found to improve the magnetic properties of the printed magnets by enhancing the magnetic texture.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Engineering, Mechanical
S. Matkovic, M. Bek, M. Kalin
Summary: In this study, we evaluated the tribological performance of polypropylene composites with wood-flour fillers obtained as a by-product from the wood-processing industry. The addition of wood fillers significantly improved the tribological performance of the composites compared to neat polypropylene materials, reducing friction coefficient and improving wear resistance. The use of wood fillers could compensate for the poorer properties of recycled materials, making the polypropylene-wood composites a suitable sustainable choice for tribological applications.
Proceedings Paper
Materials Science, Multidisciplinary
Roland Kadar, Ann Terry, Kim Nygard, Tiina Nypelö, Gunnar Westman, Sylwia Wojno, Reza Ghanbari, Mina Fazilati, Marko Bek, Amit Kumar Sonker
Summary: Hierarchical biomaterials play a crucial role in developing sustainable novel material systems. The challenge lies in controlling their assembly into hierarchical orders at different scales, especially in understanding the orientation dynamics. This study focuses on water-based suspensions of cellulose nanocrystals, but the findings can be applied to other nanostructured fluids as well.
NOVEL TRENDS IN RHEOLOGY IX
(2023)
Article
Materials Science, Ceramics
Milan Vuksic, Marko Bek, Lidija Slemenik Perse, Marjeta Macek Krzmanc, Andraz Kocjan, Aljaz Ivekovic
Summary: Fused filament fabrication (FFF) is a versatile and inexpensive AM technique for fabricating complex ceramic structures. The addition of paraffin wax (PW) resulted in the successful fabrication of flexible filaments, but had no significant impact on debinding.
Article
Chemistry, Multidisciplinary
Marko Bek, Joamin Gonzalez-Gutierrez, Christian Kukla, Klementina Pusnik Cresnar, Boris Maroh, Lidija Slemenik Perse
APPLIED SCIENCES-BASEL
(2020)