Article
Polymer Science
Mohammad M. Afroz, Yun Kyung Shin, Adri C. T. van Duin, Katie D. Li-Oakey
Summary: In this study, we used the ReaxFF simulation method to investigate the physiochemical and mechanical properties, as well as the stimuli response behavior, of a shape-memory polyurethane (SMPU) rigid segment. We developed models for both crystalline and amorphous forms of a common rigid segment of SMPUs and performed molecular dynamics simulations to predict their structural and physiochemical properties. This study provides a theoretical pathway for the application-oriented design of high-performance SMPUs in fields such as soft robotics.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Wenxiang Zhang, Zhongquan Peng, Xi Zhang, Qiwei Pan, Shumei Liu, Bo Cao, Jianqing Zhao
Summary: In this study, high-performance liquid crystalline poly(ester imide)s (LCPEIs) were successfully synthesized with tunable solubility, thermal stability, mechanical properties, and dielectric properties through copolymerization of an imide dicarboxylic acid (IA) with other monomers. The LCPEI with 10 mol% IA showed excellent combined properties and could be a promising candidate for flexible copper-clad laminate substrates.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Mingfei Xiao, Aditya Sadhanala, Mojtaba Abdi-Jalebi, Tudor H. Thomas, Xinglong Ren, Tao Zhang, Hu Chen, Remington L. Carey, Qijing Wang, Satyaprasad P. Senanayak, Cameron Jellett, Ada Onwubiko, Maximilian Moser, Hailiang Liao, Wan Yue, Iain McCulloch, Mark Nikolka, Henning Sirringhaus
Summary: The glass transition temperature (T-g) of a range of conjugated polymers with different crystallinity levels was determined using dynamical mechanical analysis. The comparison between measured and theoretically predicted T-g values revealed that the consistency is influenced by the length of monomer units and sub-bandgap optical absorption.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Physical
Artur Bukowczan, Konstantinos N. Raftopoulos, Maciej Czajkowski, Ewa Szefer, Edyta Hebda, Krzysztof Pielichowski
Summary: A series of liquid crystalline polyurethanes modified by TRIS-POSS were synthesized and characterized. The addition of POSS moieties led to the formation of liquid crystalline phases and higher melting and crystallization temperatures. POSS particles influenced thermal stability, glass transition, and mechanical properties in the polyurethanes, with no agglomerates observed.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Polymer Science
Artur Bukowczan, Konstantinos N. Raftopoulos, Jacek Niziol, Krzysztof Pielichowski
Summary: Molecular mobility and liquid crystalline order formation of liquid crystalline polyurethanes (LCPU) modified by trisilanolphenyl-POSS were studied using various techniques. The addition of POSS did not significantly alter the nanoscale morphology of the LCPU matrix. Liquid crystal phase transitions were confirmed through dielectric and differential scanning calorimetry measurements. The presence of partially cross-linked POSS particles enhanced the material's rubber modulus in dynamic mechanical analysis. Overall, POSS caused a nucleation effect and did not impair LC phase formation.
Article
Polymer Science
Kepa Zulueta, Aizeti Burgoa, Inaki Martinez
Summary: The influence of hygrothermal aging on epoxy-based C-SMC samples was studied, showing effects on thermomechanical properties but no degradation effects on mechanical response.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Polymer Science
Ding He, Qin Li, Yunjun Luo, Bixin Jin, Shumeng Chi, Xiaoyu Li
Summary: Since the discovery of the aggregation-induced emission (AIE) phenomenon, it has been widely used in various fields. This study attempted to use tetraphenylethylene (TPE) to characterize liquid crystalline (LC) transitions of cholesteryl-containing homopolymers. It was found that directly blending TPE into the homopolymer matrix disrupted the LC transition, but labeling TPE onto one of the chain ends of homopolymers did not affect the transition results.
Article
Polymer Science
Joseph S. Terry, Ambrose C. Taylor
Summary: Manufacturers are considering bio-based alternatives to petroleum-derived epoxies due to environmental concerns, but a lack of information hinders this substitution. Commercially available bio-based epoxy systems are being compared, with high bio-based content resins used for vacuum infusion composites, showing promising mechanical properties comparable to conventional epoxies.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Tian Li, Ying Shen, Guangping Zheng
Summary: A new exponent beta has been proposed to characterize the glass forming ability of metallic nano-glasses (NGs) and metallic glasses (MGs), showing that higher beta values indicate enhanced GFAs in NGs with a higher volume fraction of glass-glass interfaces (GGIs), which can potentially overcome the size limitation issue in MGs.
SCRIPTA MATERIALIA
(2021)
Article
Biochemistry & Molecular Biology
Wei Li, Lanjuan Wu, Zhifeng Zhu, Zhengqiao Zhang, Qian Liu, Yuhao Lu, Huizhen Ke
Summary: The study aimed to investigate the influence of PSAS branches on the sizing properties of corn starch, leading to the development of a new starch-based size. Results showed that S-g-PSAS exhibited improved adhesion, viscosity stability, desizability, and film properties compared to HS, with enhancements in bonding forces, viscosity stability, and film properties at higher grafting ratios. This suggests potential for S-g-PSAS as a sizing agent for cotton and viscose fibers.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Chemistry, Applied
Ruixue Zhang, Hongwei Ma, Xuwen Li, Jiaxin Yang, Meng Lai, Xueli Zhang, Yu Wang, Yang Li, Li Han
Summary: Polystyrenes with photochemical stability were synthesized through anionically copolymerizing Si-H functionalized 1,1-diphenylethylene with isoprene/styrene. These PS-based materials were combined with liquid crystalline azobenzene-cholesterol moieties to achieve photo-responsiveness. The trans-cis isomerization efficiency under UV-light and Visible-light irradiation was evaluated, providing guidelines for the design of photo-responsive anisotropic materials.
Article
Polymer Science
Hassan Alshahrani, Abdul Qadeer Dayo, Wen-bin Liu
Summary: Silane coupling agent-treated glass fiber reinforced composites exhibit improved impact strength compared to the as-received counterparts, and an increase in flexural strength, flexural modulus, tensile strength, and Young's modulus with increasing fiber reinforcement. DMA results show that as the fiber reinforcement increases, storage modulus and glass transition temperature gradually increase while damping factor decreases. The 40 wt% TGF reinforced poly(BA-a/EPN) composite demonstrates high thermal stability and self-extinguishing properties.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Enosha Harshani De Silva, Bruce M. Novak
Summary: Carbodiimide polymers with bulky branched aliphatic and octadecyl side chains were studied for their solid and solution properties. It was found that polycarbodiimides containing octadecyl and branched alkyl side chains exhibited different thermal events at around 30 degrees C, and increased branched alkyl side chains led to decreased thermal stability. Lyotropic liquid crystallinity was observed in branched copolymers with a combination of branched alkyl side chains and octadecyl functional groups in different ratios.
Article
Polymer Science
Simone Donato, Daniele Martella, Martina Salzano de Luna, Giulia Arecchi, Silvia Querceto, Cecilia Ferrantini, Leonardo Sacconi, Pierre-Louis Brient, Camille Chatard, Alain Graillot, Diederik S. S. Wiersma, Camilla Parmeggiani
Summary: Phase behavior of liquid crystalline molecules can be controlled through structural modification at the molecular level. Reduction in symmetry or increase in steric hindrance by substituents can lower the clearing temperature. Similar strategies can be used for liquid crystalline networks (LCNs) to tailor their properties for various applications.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
An N. Le, Ruiqi Liang, Xiaoyu Ji, Xiaowei Fu, Mingjiang Zhong
Summary: Random copolymerization of norbornene-functionalized macromonomers is a method for synthesizing mixed-graft block copolymers, which can lead to stable phase-separated nanostructures with different side chain compositions. The graft architecture enhances the processability of the material.
JOURNAL OF POLYMER SCIENCE
(2021)
Article
Polymer Science
Behiye Ozturk Sen, Sedat Cetin, Ugur Yahsi, Ugur Soykan
Summary: Graft copolymerization of BPOCPMA onto HDPE led to improvements in mechanical properties and crystal structure, with decreases in free volume fraction as the content of BPOCPMA increased.
JOURNAL OF POLYMER RESEARCH
(2021)
Article
Construction & Building Technology
Mustafa Khaleel, Ugur Soykan, Sedat Cetin
Summary: The study found that the thermal stability of RPUFs was improved at low percentages of TFFs, but the effect weakened as the content increased. Meanwhile, the thermal insulation performance and acoustic features were also influenced to some extent by TFFs, which can reduce the air permeability of the foam.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Composites
Ugur Soykan
Summary: The study focused on the impact of natural turkey feather fibers (TFFs) loading on the fundamental properties of thermoplastic polyurethane (TPU), including thermal, mechanical, water-uptake, and micro-structural features. The addition of TFFs led to improvements in melting temperatures, tensile strengths, and modulus at lower loading levels, but also increased water-uptake capacities and micro-structural defects at higher levels.
JOURNAL OF COMPOSITE MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
N. Kaya, S. Cavdar, O. Ozturk, G. Yildirim, H. Koralay
Summary: This study demonstrates that adding 2% carbon nanotubes in MgB2 superconducting material is optimal, leading to improved fundamental characteristics despite slightly degrading some general properties.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Chemistry, Physical
U. Soykan, Y. Sert, G. Yildirim
Summary: In this study, the ODDFA molecule was synthesized and characterized both experimentally and theoretically. The results show good correlation between computations and experiments, with the molecule exhibiting kinetic chemical stability and both nucleophilic and electrophilic reactive regions on its surface. Molecular docking studies confirm the potential of ODDFA as a potent inhibitor, and drug-likeness analysis reveals considerable bioactivity.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Anatomy & Morphology
Fatih Bulut, Ozgur Ozturk, Selim Acar, Gurcan Yildirim
Summary: The addition of aluminum and nickel impurities affects the characteristics of ZnO nanorods, including crystallinity quality, nanorod diameter, gas response, etc. The 5% Ni-doped sample shows better CO2 gas sensing performance.
MICROSCOPY RESEARCH AND TECHNIQUE
(2022)
Article
Materials Science, Ceramics
A. T. Ulgen, Samet Cetin, Y. Zalaoglu, M. B. Turkoz, U. Erdem, G. Yildirim
Summary: The effect of Ho/Bi partial replacement in Bi-2212 superconductors on their structural, morphological, and mechanical properties was investigated using SEM and Vickers hardness measurements. The results showed that the proper Ho concentration enhanced the characteristics of the superconductors due to improved crystallinity quality and slip systems. However, an excessive amount of Ho ions induced crack-initiating defects. The study also analyzed the indentation size effect and compared different mechanical modeling approaches.
CERAMICS INTERNATIONAL
(2022)
Article
Engineering, Biomedical
Umit Erdem, Deniz Dogan, Buesra Moran Bozer, Seda Karaboga, Mustafa Burak Turkoz, Aysegul Ulku Metin, Gurcan Yildirim
Summary: This multidisciplinary study investigated the change in the properties of hydroxyapatite (HAp) biomedical materials due to fluorine addition and degradation process. The results showed that adding 2% fluorine improved the stability and structural quality of HAp, while excessive fluorine caused increased degradation rates. The optimal addition of fluorine enhanced the durability and mechanical properties of HAp materials.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
M. Dogruer, G. Yildirim, C. Terzioglu
Summary: This paper provides a comprehensive characterization of Bi-2223 ceramic material with aliovalent Nd/Sr replacement, revealing that the replacement mechanism seriously damages the fundamental electrical, superconducting, crystallinity and structural features. The study shows that the substitution level affects the superconducting and electrical properties, characteristic transition temperatures, average crystallite size, and structural quality.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Materials Science, Biomaterials
Ugur Soykan, Senol Kaya
Summary: In this study, rigid polyurethane foams (RPUFs) composites were prepared by adding different percentages of hemp fibers. The effects of hemp fiber addition on the RPUFs were investigated using various techniques to evaluate changes in the chemical structures, thermal stability, density, insulation performance, and cellular structure of the samples. The results showed that the hemp fibers improved the thermal stability and interfacial adhesion of the foams, but also increased the thermal conductivity and negatively affected the cellular morphology and dimensional stability.
Article
Chemistry, Applied
Ugur Soykan, Mustafa Khaleel, Sedat Cetin, Ugur Yahsi, Cumali Tav
Summary: In this study, the effects of adding turkey feather fibers (TFFs) on the mechanical properties, water vapor permeability (WVP), and free volume of rigid polyurethane foams (RPUFs) were investigated. The results showed that the addition of TFFs decreased the free volume, tensile strength, and elongation of the foams. Furthermore, TFFs negatively affected the compressive performance and impact energy distribution of the foams, as well as significantly reducing the WVP.
JOURNAL OF CELLULAR PLASTICS
(2022)
Article
Materials Science, Composites
Ugur Soykan, Sedat Cetin
Summary: This study aims to prepare crosslinked ABCF13 polymer microspheres and investigate their effects on the crystallinity, thermal, mechanical, and morphological properties of HDPE. Well-defined microspheres were produced by suspension polymerization, with microsphere content varying from 1.0% to 10.0% in the composites. Characterization techniques revealed that the a and b unit cell parameters of the composites initially increased and reached a maximum with 5.0% microsphere content, followed by a dramatic decrease, while the c parameter remained relatively unchanged. Thermal analysis showed that the melting temperature of HDPE decreased with the initial loading of microspheres and then stayed at a plateau value of about 129 degrees C due to lattice distortions and microstructural disorders. The mechanical tests demonstrated improvements in tensile strength, modulus, and impact strength, with the blend containing 5.0% microsphere achieving the highest values. SEM analysis showed changes in fibrillar formations and a transition from ductile to brittle behavior with increasing microsphere content.
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
(2023)
Article
Materials Science, Ceramics
Ali Mercan, Rifki Terzioglu, Muhsin Ugur Dogan, Senol Kaya, Umit Erdem, Gurcan Yildirim, Cabir Terzioglu, Ahmet Varilci
Summary: This study investigated the effects of different annealing temperatures on the surface morphological and mechanical performance properties of Zr surface-layered Bi-2223 materials. It was observed that annealing at 650°C resulted in superior performance due to enhanced deformation and the presence of Zr ions acting as nucleation centers to prevent crack propagation. Diffusion mechanisms also contributed to improved performance by increasing the random distribution of granular structures and reducing coupling problems between grains.
CERAMICS INTERNATIONAL
(2023)
Article
Engineering, Biomedical
Deniz Dogan, Umit Erdem, Busra M. Bozer, Mustafa B. Turkoz, Gurcan Yildirim, Aysegul U. Metin
Summary: In this study, silver-doped hydroxyapatite (AgHA) reinforced Xanthan gum (XG) and Polyethyleneimine (PEI) reinforced semi-interpenetrating polymer network (IPN) biocomposite were produced and characterized. The nanocomposite films showed high antibacterial activity and good biocompatibility, making them potential materials for bone tissue regeneration.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Materials Science, Biomaterials
Ugur Soykan, Sedat Cetin, Ugur Yahsi
Summary: This study investigated the insulation and permeability performances of rigid polyurethane foams (RPUFs) containing different contents of micron-sized turkey feather powders (TFPs). The addition of TFPs led to a decrease in free volume parameters and worsened thermal conductivity and acoustic performance of the resulting foams. Additionally, the foam samples with high TFPs content showed lower air and water vapor permeabilities. SEM analysis revealed good compatibility between TFPs and RPUF, but distorted and irregular cellular morphology was observed at high contents.
