Article
Polymer Science
Akihiro Hanafusa, Shota Ando, Tetsuharu Yuge, Satoru Ozawa, Masakazu Ito, Ryuichi Hasegawa, Hideaki Yokoyama, Koichi Mayumi, Kohzo Ito
Summary: In our previous study, we found that the incorporation of polyrotaxane (PR) into epoxy resins as an additive can enhance the mechanical toughness. In this study, we further modified PR by introducing epoxy groups (PR-E) to enable its incorporation into crosslinked epoxy networks. The chemical bonding of PR-E to the epoxy resins suppressed the mobility of the PCL graft chains and improved the mechanical properties.
Article
Chemistry, Physical
Timur Khamidullin, Ivan Lounev, Alexander Solodov, Iskander Vakhitov, Seyyed Alireza Hashemi, Ayrat M. Dimiev
Summary: This study introduces graphene oxide sheets into epoxy resin, and orients them with an external magnetic field to create composites with significant anisotropy in electric properties. The developed protocol allows for the fabrication of anisotropic materials with high performance, showing promising applications for antennas, radars, vibration sensors, dielectric lenses, etc. The physics behind the electrical conductivity of the composite materials is defined as interfacial polarization.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Engineering, Electrical & Electronic
Zhicheng Wu, Binqi Lin, Jiasheng Fan, Junping Zhao, Qiaogen Zhang, Licheng Li
Summary: This article investigates the dielectric loss of epoxy resin (EP) in medium-frequency transformers (MFTs) through experiments and simulations. The results show that the addition of anhydride hardeners containing benzene ring or a methyl substituent can reduce the dielectric loss, and the EP cured by methyl nadic anhydride (MeNA) has the lowest dielectric loss. This study provides important insights for the selection of insulating materials in MFTs.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Chemistry, Physical
Jiadong Lu, Songli Zhang, Leizhi Zhang, Chenxi Wang, Chunying Min
Summary: In this study, an ethyl phenylacetate-cured dicyclopentadiene phenol (DCPD) epoxy resin was used as the matrix, and KH550 coupling-agent-treated SiO2 hollow glass microspheres were incorporated to produce composite materials with low dielectric, high heat resistance, and high modulus. The prepared epoxy resin composite material exhibited good comprehensive performance, with a dielectric constant of 2.39 and a dielectric loss of 0.018 at 10 MHz. The thermal conductivity was 0.1872 Wm(-1) k(-1), the coefficient of thermal expansion was 64.31 ppm/K, the glass transition temperature was 172°C, and the elastic modulus was 1221.13 MPa when the hollow glass microsphere content was 10 wt.%.
Article
Polymer Science
Junji Wei, Yajun Duan, Hao Wang, Wanping Zhang
Summary: In this study, DPAE was modified with DPR and CE to improve its dielectric properties while maintaining good heat resistance and low dimensional stability. Compared to DPAE resin, both DPAE/DPR and DPAE/CE composites exhibited higher glass transition temperatures, lower dielectric constants, lower loss tangents, and good compatibility with the two resins. Moreover, CE resin showed better modification effect on the thermal and dielectric properties of DPAE.
Article
Polymer Science
Mingru Li, Jiuhui Zhao, Kai Shang, Zhenlian An, Jingpeng Sun, Xin Wang, Jianyu Lang, Huan Niu, Yang Feng, Shengtao Li
Summary: The dielectric response of polymer dielectrics is crucial for their applications in electronic devices. The effects of fluorine hybridization on the dielectric response of polymers, particularly in terms of temperature dependence, remain unclear. In this study, surface fluorination was performed to create fluorine hybrid epoxy resin (EP), and the dielectric response of EP before and after fluorination was investigated. It was observed that at low temperatures, the electronic polarization dominated the dielectric response, while at higher temperatures, the fluorine hybridization led to an enhanced dipolar polarization and increased permittivity. This research sheds light on the influence of fluorine hybridization on the dielectric response of epoxy polymers and can promote the utilization of organic dielectrics in communication and electronic devices.
Article
Construction & Building Technology
Yuxuan Wang, Quansheng Liu
Summary: The study demonstrated that water-soluble epoxy resin can effectively improve the performance of cement-based grout, especially in terms of compressive strength and tensile strength. The modification with epoxy resin significantly enhances the properties of composite grout, as shown by rheological and mechanical analysis.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Physics, Applied
Y. F. Wang, B. X. Du, X. X. Kong, Fan Li, Xin Lin
Summary: This paper investigates the influence of network structure on the dielectric properties of bisphenol A, bisphenol F epoxy resin and their blends. The results show that substituting isopropyl with methylene in epoxy resin enhances the molecular chain packing efficiency, thus limiting the polarization effect while reducing glass transition temperature (T (g)). As the content of bisphenol F resin in the blends increases, the polarization loss of the blends continues to decrease, to even lower than that of bisphenol F resin. For the blend containing 20% bisphenol F resin, the T (g) and AC breakdown strength at high temperatures are higher than that of bisphenol A resin. Furthermore, based on molecular dynamics simulation, the reason for the limited polarization effect of the blends is further discussed.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Zhengbiao Yu, Xiaomeng Du, Pengli Zhu, Tao Zhao, Rong Sun, Jianzhong Chen, Ning Wang, Weihua Li
Summary: In this work, the interface binding strength between HGMs and the resin matrix in composites is improved by surface modification. As a result, the maximum filling ratio of HGMs in the epoxy resin reaches 35 wt. % (67 vol. %). The highly improved filling ratio benefits the HGMs-EP composites with improved thermal insulation and low thermal conductivity. Additionally, the composites filled with 67 vol. % HGMs also exhibit a significantly reduced permittivity, making them promising for 5G communication technology.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Jianliang Jiang, Jingbo Shen, Xiao Yang, Dongqi Zhao, Yakai Feng
Summary: To enhance the thermal and mechanical properties of epoxy resins, epoxy-functionalized POSS (E-POSS) and glass fiber (GF) were utilized as reinforcements in epoxy resin (E51) composites. Tensile, thermo-mechanical, fractured, and thermal tests were conducted to evaluate these hybrid materials. The findings demonstrated that E-POSS and GF effectively enhanced the mechanical and thermal properties of epoxy resins due to the high crosslink density of the resin matrix and the synergistic interaction between epoxy resin, E-POSS, and GF. Compared to the pure E51 resin, the tensile strength of the E51 + E-POSS (10%) + GF (16%) sample increased by 257.6%, while the thermal decomposition temperature (T-d5%) increased by 32 degrees C, reaching 378 degrees C.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Environmental
Xiao-Feng Liu, Yan-Fang Xiao, Xi Luo, Bo-Wen Liu, De-Ming Guo, Li Chen, Yu-Zhong Wang
Summary: In this study, a high-performance and multifunctional epoxy resin EP-DPI was successfully synthesized by incorporating a functional molecule DPI, which exhibited excellent mechanical performance, high glass transition temperature, transparency, UV-shielding effect, and anti-ignition properties. This work opens up a new strategy for developing novel high-performance and multifunctional EPs with potential versatile applications in various fields.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Bhargav Sai Chava, Eva K. Thorn, Siddhartha Das
Summary: This study investigates the shear-thinning behavior of graphene flake-infused epoxy inks using molecular dynamics simulations. It is found that the viscosity of GFI epoxy ink is higher than that of pure epoxy ink at lower shear rates, while the two viscosities become similar at higher shear rates. The alignment of bisphenol F molecules and graphene flakes plays a crucial role in dissipating viscous force and ensuring shear-thinning behavior. Additionally, the presence of graphene flakes significantly affects the rotational dynamics of bisphenol F molecules, leading to a much higher zero-shear viscosity for GFI epoxy compared to pure epoxy.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Polymer Science
Yongqiang Wang, Zhuo Zeng, Meng Gao, Ziye Huang
Summary: The addition of diphenylsilanediol to epoxy resin as a modifier improves the hygrothermal aging resistance and dielectric properties of silicone-modified insulation materials. The presence of diphenylsilanediol reduces the size of cracks in the material during hygrothermal aging, leading to better overall performance. However, excessive silicone material in the epoxy resin may result in poorer dielectric properties.
Article
Polymer Science
Junji Wei, Yajun Duan, Hao Wang, Jizhuang Hui, Jiamin Qi
Summary: In this paper, a trifunctional epoxy resin (DPA-E) was prepared using diphenolic acid and epichlorohydrin as substitutes for traditional bisphenol A epoxy resin (DGEBA). The DPA-E showed similar properties to DGEBA except for curing temperature, glass transition temperature, and thermal expansion properties. With a low gel temperature and high glass transition temperature, DPA-E/DMDC has promising applications in aerospace and microelectronics.
Article
Polymer Science
Dujuan Zhang, Yafeng Li, Haijun Lu, Fugui Zhao, Jue Cheng, Junying Zhang
Summary: This study combines molecular dynamic simulation with experimental study to explore the main control factors of the dielectric constant of Dicyandiamide cured epoxy resin. The density and glass transition temperature obtained by experiment and simulation were compared for validation of the simulation models. Dielectric constant was calculated using the dipole fluctuation formula, with motion mobility, polarity, and free volume employed to explain the influence mechanism of conversion on the dielectric constant. The results showed that the dielectric constant is controlled by the content of unreacted monomers, especially Dicyandiamide, before gelation, and by segmental mobility, hydroxyl group density, and free volume after gelation, with the influence of segmental mobility being more significant than that of free volume and hydroxyl group density.
Article
Polymer Science
Orestis Vryonis, Satpreet Riarh, Thomas Andritsch, Alun S. Vaughan
Summary: The influence of octa-glycidyl (OG) cubic silsesquioxane and reaction stoichiometry (stoichiometry factor, SF) on the cure chemistry and molecular dynamics of an anhydride-cured epoxy resin is reported. An excess of epoxide groups suppresses esterification and glass transition temperature (T-g), while system-to-system network variations arising from changes in the degree of esterification and etherification are not sufficient to form discrete dielectric beta processes. The proposed generic interpretation for the gamma dielectric relaxation involves competing origins reported in the literature, namely gamma(1) (local motions of main-chain segments) and gamma(2) (unreacted moieties).
Article
Chemistry, Physical
Orestis Vryonis, Alun S. Vaughan, Thomas Andritsch, Peter H. F. Morshuis, Aurore Claverie
Summary: This paper investigates the tensile properties and molecular dynamics of an epoxy resin system containing an accelerator. It is found that a relaxation process, named gamma relaxation, occurs at low temperatures, followed by a stronger relaxation before the onset of charge transport. The study also reveals the close relationship between charge transport and cooperative molecular motion.
Article
Engineering, Electrical & Electronic
Phichet Ketsamee, Thomas Andritsch, Alun Vaughan
Summary: This study investigates the effects of surface modification of titanium dioxide (TiO2) and magnesium oxide (MgO) nanofillers on the dielectric response of polypropylene (PP) nanocomposites in the presence of water molecules. Thermogravimetric analysis (TGA) reveals significant differences in the surface structure of the nanofillers due to varying graft density of the silane coupling agents (SCAs). Surface-modified nanofillers tend to agglomerate, with distribution influenced by the polarity of the surface functional groups. The increase in relative permittivity in the composites is attributed to absorbed water, and surface modification reduces this increase, especially for MgO samples.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Materials Science, Multidisciplinary
Sunny Chaudhary, Orestis Vryonis, Alun Vaughan, Thomas Andritsch
Summary: We conducted a comparative study on the molecular dynamics of epoxy nanocomposites filled with different types and crystallinity of silica-based nanoparticles. We observed various well-known relaxations and discovered a new relaxation process that is inversely correlated to the crystallinity of the nanoparticles. Additionally, two weaker interfacial polarization relaxations were observed in core-shell structures.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Energy & Fuels
Phichet Ketsamee, Orestis Vryonis, Alun Vaughan, Thomas Andritsch
Summary: This study investigates the impact of magnesium oxide (MgO) nanoparticles on the thermo-oxidative aging behavior of blends of polypropylene (PP) and ultra-high molecular weight polyethylene (UHMWPE). It found that MgO can improve the compatibility of PP/UHMWPE blends and delay the aging process.
Article
Energy & Fuels
Emmanuel Taine, Thomas Andritsch, Istebreq A. Saeedi, Peter H. F. Morshuis
Summary: This study investigates the effects of Mullins damage and mechanical fatigue on silicone elastomers. The results show that the first cycle leads to a 30% reduction in the mean breakdown strength, while subsequent mechanical fatigue has minimal contribution to the degradation.
Proceedings Paper
Engineering, Electrical & Electronic
Kevin Goddard, Orestis Vryonis, George Callender, Thomas Andritsch, Paul Lewin, Simon Gao
Summary: This paper constructs finite element analysis (FEA) simulations to accurately calculate heat transfer within a high voltage (HV) cable tunnel system. The simulations demonstrate that a decrease in air velocity in the outlet shaft leads to an increase in cable temperature, which impacts the power flow capability of the circuit. Accurately calculating heat transfer in complex cable installations is crucial to prevent premature equipment failure.
2023 IEEE ELECTRICAL INSULATION CONFERENCE, EIC
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Xiwen Wu, Thomas Andritsch, George Chen
Summary: The potential application of eco-friendly thermoplastic material - Polypropylene (PP) for high voltage direct current (HVDC) cable has attracted attention. In this work, an antioxidant (AO) was introduced to investigate its influence on the thermal-oxidative ageing of PP for long-term performance under high temperature. The chemical changes and space charge dynamics were characterized, and the results showed that AO could increase the DC breakdown strength at an early stage of the ageing process.
2022 IEEE CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA (IEEE CEIDP 2022)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Luming Zhou, Thomas Andritsch, George Chen
Summary: This study investigates the effect of recrystallization on charge accumulation in polypropylene (PP). It is found that recrystallization leads to an increase in charge traps and total charge accumulation in PP, while the change in the internal microstructure of the crystal has no effect on space charge accumulation.
2022 IEEE CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA (IEEE CEIDP 2022)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Phichet Ketsamee, Thomas Andritsch, Alun Vaughan
Summary: This work investigates the effects of surface-modified magnesium oxide nanoparticles on the mechanical properties and AC breakdown strength of polypropylene and ultra-high molecular weight polyethylene composites. The addition of nano-MgO enhances the breakdown strength and stiffness of the composites by improving interfacial adhesion between the polymers. The interfacial adhesion significantly affects the dielectric breakdown strength and elastic enhancement of the materials.
2022 IEEE CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA (IEEE CEIDP 2022)
(2022)
Article
Engineering, Electrical & Electronic
Norhafezaidi Mat Saman, Noor' Aliaa Awang, Mohd Hafizi Ahmad, Zolkafle Buntat, Mat Uzir Wahit, Nikola Chalashkanov
Summary: This study investigates the effects of atmospheric pressure plasma treatment on SiO2 nanoparticles in enhancing the PD resistant and breakdown strength characteristics of LDPE nanocomposites. The results demonstrate that plasma treatment can improve the dielectric properties of LDPE nanocomposites.
IEEE TRANSACTIONS ON NANOTECHNOLOGY
(2022)
Article
Polymer Science
Yuanzhang Jiang, Xuyi Wang, Yanting Han, Dakai Gong, Yingchun Gu, Lin Tan
Summary: In this study, FeCl3 and poly(acrylic acid) (PAA) were doped into waterborne polyurethanes (WPUs) to create multifunctional materials with self-healing and antimicrobial properties. WPU/Fe/PAA-5.5, containing 5.5 wt % PAA, exhibited excellent mechanical properties, strong self-healing capabilities, and an impressive antimicrobial rate of over 90%. These supramolecular films were also highly recyclable through hot-pressing.
Article
Polymer Science
Longyu Tian, Min Wang, Guangming Liao, Baoliang Liu, Sujuan Zhang, Yucheng Sun, Zhen Meng, Jintao Zhang, Zaijun Lu
Summary: Two kinds of benzoxazine monomers were synthesized and used to prepare polybenzoxazine anion exchange membranes (AEMs) with quaternary ammonium functionalization. The LQPBZ AEM exhibited better ion conductivity and alkaline stability.
Article
Polymer Science
Claire A. Lemarchand
Summary: This study investigates the shock behavior of three different polymers through molecular dynamics simulations. The results reveal specificities in the shock behavior of polymers, including deviations from the linear relation between shock velocity and particle velocity, as well as differences in shear stress relaxation behind the shock front. It is found that the deviation of the Hugoniot locus is related to the change in the relative contribution of bonding and non-bonding potential energies, while polymers with higher glass transition temperatures exhibit slower shear stress relaxation.
Article
Polymer Science
Zengquan Liu, Xiaochun Yin, He Zhang, Shuo Gao, Qinglin Kuang, Yanhong Feng
Summary: A powder solid-state extension (PSSE) technology was proposed to address the high melt viscosity issue of UHMWPE. By uniaxial extension and sintering in the solid state, a highly self-reinforced material was prepared. X-ray diffraction and scattering techniques were used to study the structural evolution during the PSSE process, and a solid-phase induced transformation model was established.
Article
Polymer Science
Zhike Li, Anyu Luo, Rui Zhou, Xin Li, Haiyan Li
Summary: A novel high temperature resistance IL@SiO2 nanocapsules were successfully prepared and their friction and wear properties in PA6 composites were studied. The addition of IL@SiO2 nanocapsules reduced the friction coefficient and wear rate without affecting the mechanical properties of PA6. The synergy between the IL core and SiO2 wall in the nanocapsules improved the self-lubricating performance of the PA6 composites.
Article
Polymer Science
Xin Liu, Xuhong Guo, Qi Liao
Summary: In this study, an algorithm for accurately estimating viscosity is developed using molecular dynamics simulations and the Green-Kubo formula. This algorithm can be applied to complex systems with long correlations, such as macromolecular and biological simulation systems.
Article
Polymer Science
Hao Pu, Yun-Lei Hou, Jing -Zhou Chen, Dong -Lin Zhao
Summary: The use of modified graphene improves the interfacial adherence of carbon fibers to epoxy resin, resulting in enhanced interfacial and bending properties of CF and matrix in CF/EP composites, as well as increased interlaminar shear strength and flexural strength.
Article
Polymer Science
Wei-Chung Ke, Jin-Wei Lin, Manohar Reddy Busireddy, Yueh-Hsing Lee, Jiun-Tai Chen, Chain-Shu Hsu
Summary: This study introduces a crosslinkable monomer, TAIC, to synthesize three crosslinked polyimide films, which exhibit improved thermal, mechanical, and dielectric properties. The introduction of TAIC enhances the tensile strength, reduces the dielectric constant and dielectric loss, and decreases the coefficient of thermal expansion of the polyimide films.
Article
Polymer Science
Alex Kwasi Kumi, Ruiling Fan, Ye Chen, Yumei Zhang
Summary: The difference in leaching of amylopectin from cellulose/amylopectin/1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) blends during regeneration in water and aqueous ethanol has been studied. Molecular dynamics simulations showed that the dissolution and regeneration mechanisms of amylopectin in [Bmim][Cl] are similar to cellulose in ionic liquids. Water regeneration leads to weak electrostatic interactions, resulting in high leaching of amylopectin. In contrast, ethanol-water interactions enhance electrostatic interactions among amylopectin chains, limiting amylopectin leaching in aqueous ethanol.
Article
Polymer Science
Xi Zeng, Junwei Zhou, Junbiao Peng, Chunsheng Zhang, Danling Wang, Yihu Song, Qiang Zheng
Summary: This study utilizes an oligomer deep eutectic solvent (DES) based on polyethylene glycol to regulate the vulcanization kinetics of rubber. The results show that the DES can accelerate vulcanization at low temperatures without affecting the crosslinking density and Mullins effect.
Article
Polymer Science
Qianqian Yue, Yongfei Peng, Xingjian Liu, Aihua He, Huarong Nie
Summary: The addition of metal deactivators can effectively suppress the aging of TBIR, prolong its lifespan, and have no negative effects on its physical and processing properties. These research findings are of great importance for improving the stability and aging resistance of polymers.
Article
Polymer Science
J. Gomez-Caturla, J. Ivorra-Martinez, R. Tejada-Oliveros, V Moreno, D. Garcia-Garcia, R. Balart
Summary: This work focuses on the development of environmentally friendly PLA formulations by using different esters derived from geraniol as plasticizers. The results show that these esters have good compatibility with PLA, and they can effectively enhance the elongation and plasticity of PLA, reduce its glass transition temperature, and slightly improve its water absorption capabilities.
Article
Polymer Science
Dandan Li, Zhaohui Lu, Zhao Ke, Ke Xu, Fengna Dai, Youhai Yu, Guangtao Qian, Chunhai Chen
Summary: In this study, cross-linked PI aerogel membranes with low dielectric constant and high moisture resistance were prepared by co-polymerization and scraping coating technology. The incorporation of fluorinated blocks and benzimidazole ring structures resulted in novel PI aerogel membranes with fascinating dielectric properties and outstanding moisture resistance.
Article
Polymer Science
Zhaoyang Chu, Qing Zhang, Haihua Luo, Han Zhou, Fapei Zhang, Wei Chen, Wenhua Zhang
Summary: Multi-physical fields solution processing strategy is a universal and facile method for preparing various conjugated polymer films and high-performance devices. In this study, we employed a combined microfluidic flow and ultrasonication strategy (FU) for processing CP solutions, and found a pronounced synergetic effect in promoting the pre-ordering of chains in solution. The conformation order and anisotropy of the solution were revealed through various characterizations. A non-classical nucleation model for polymer crystallization in non-equilibrium solution processing was confirmed. The roles of microfluidic flow and ultrasonication in chain aggregation and crystallization were addressed through multi-physical simulations. Compared to pristine solutions, the FU strategy showed improved solution anisotropy and crystallization kinetics, resulting in higher crystallinity in films and increased mobilities in OFET devices. The FU processing strategy provides a universal approach for regulating chain conformation and aggregation in conjugated polymer solutions.
