IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
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2024
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IF 2.9
Phichet Ketsamee,Alun Vaughan,Thomas Andritsch
This work highlights the potential of polypropylene (PP) as a power cable insulation material by blending with ultrahigh molecular weight polyethylene (UHMWPE), as well as blends filled with magnesium oxide (MgO) nanoparticles. In PP/UHMWPE blends, increasing the UHMWPE content up to 50 weight percentage (wt.%) increases the number of interfaces between PP and UHMWPE, promoting heterogeneous surface nucleation and strengthening the interfacial adhesion. This enhanced interfacial adhesion in PP/UHMWPE blends results in improved dielectric properties, particularly reduced relative permittivity, suppressed charge accumulation, and decreased dc electrical conductivity. In PP/UHMWPE/MgO nanocomposites, MgO nanoparticles are primarily observed at the interface between PP and UHMWPE in the PP phase. The presence of MgO does not function as a nucleating agent; instead, it acts as a compatibilizer, promoting the dispersion of UHMWPE and enhancing the interfacial adhesion between both polymers. The improved dispersion of UHMWPE results in the nonformation of phase co-continuity within the PP matrix; consequently, adding MgO up to 3 wt.% is insufficient to establish the interfaces forming percolating pathways. Thus, the good dispersion and compatibilizing effect of MgO between the PP and UHMWPE interfaces enhance interfacial adhesion and further improve the dielectric properties compared to the unfilled PP/UHMWPE blend counterparts.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Qianbin Ni,Mei Chen,Yuming Chen,Wei Li,Qi Zhou,Jincheng Dai,Shuyao Ye,Binbo Jiang,Jingdai Wang,Yongrong Yang
Polyhedral oligomeric silsesquioxane (POSS) nanoaggregates can serve as a modifier of the MgCl2-supported Z-N catalyst, thus controlling the polymerization behavior and modifying the microstructure of the synthesized polymer. In this study, a series of POSS-modified MgCl2-supported Z-N catalysts were explored to reveal the relationship between the entanglement formation of ultrahigh-molecular-weight polyethylene (UHMWPE) and the adhesive effect control of hydroxy groups in POSSs. X-ray photoelectron spectroscopy (XPS) and CO in situ FTIR low-temperature adsorption technology were employed to investigate the catalytic surface structure. It was evidenced that POSSs can coordinate with the MgCl2 (110) plane, acting as adhesive of a cage structure to be in situ embedded into the MgCl2-based support. Therefore, the loaded TiCl4 active sites were isolated in the molecular scale on the MgCl2-based support and the entanglements were greatly suppressed thereof. The ″adhesion effect″ of the MgCl2 support can be controlled by adjusting the type (i.e., hydroxyl content) of POSS introduced, thereby suppressing entanglements to a greater extent. The MgCl2 support modified with POSS with no hydroxy groups endowed it with the optimum entanglement reduction effect. As a consequence, the as-synthesized polyethylene exhibits an overall promotion of the impact resistance (+14.1%), tensile strength (+13.9%), Young’s modulus (+16.8%), and break elongation (+10.5%), compared to those of UHMWPE synthesized from the POSS-free catalyst. In addition, the POSS-modified MgCl2-based catalyst shows more stable catalytic activity and responsiveness of molecular weight with hydrogen modulation, which exhibits great prospects of industrial application in polyethylene production.
研究领域:
材料科学
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高分子化学
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催化化学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
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2025
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IF 6.3
Shiyang Wang,Liting Wei,Xinglong Zhao,Lantian Li,Yuxin Gao,Shuang Chen,Yang Yang,Boping Liu,Yulong Jin
A series of mono-, bi- and tri-metallic catalysts including Ind 2 ZrCl 2 /silica, CrO x /VO x /silica and CrO x /VO x /Ind 2 ZrCl 2 /silica were synthesized for C 2 H 4 polymerization in this work. The results show that conventional cocatalyst TiBA could hardly activate Ind 2 ZrCl 2 /silica. However, under the assistance of the surface species over CrO x /VO x /silica, traces of TiBA (Al/metal ＜15, molar ratio) endowed the Zr species with moderate activity. The combined results of XPS, FTIR-pyridine-adsorption and DRS Uv–vis show that the Lewis acidic Cr and V sites could interact with Ind 2 ZrCl 2 and improve the electronic deficiency of Zr center, which is possible to promote zirconocene activation, though direct Si-O-Zr linkage was non-negligible, and redox between Cr(VI)/V(V) and zirconocene existed. The Zr species were responsible for ultra-high molecular weight polyethylene (UHMWPE) synthesis, and the relative content of UHMWPE fractions could be controllably regulated by polymerization temperature, partial pressure of hydrogen and the loading amount of Zr. Generally, these tri-metallic catalysts CrO x /VO x /Ind 2 ZrCl 2 /silica could synthesize trimodal HDPE/UHMWPE in-reactor blends with very broad molecular weight distribution. Meanwhile, owing to the excellent copolymerization ability of zirconcene, preferential distribution of the short chain branches along the ultra-high molecular weight (MW) chains for C 2 H 4 /1-hexene trimodal copolymers was achieved. The rheological results show that the fractions with extreme MW difference in the trimodal polyethylene (PE) exhibited excellent miscibility, and its superiority in processing and mechanical properties over the monomodal PE with similar MW was verified by rheological, tensile and impact tests.
研究领域:
材料科学
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高分子化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CLINICAL ORTHOPAEDICS AND RELATED RESEARCH
·
2019
·
IF 4.154
Yue Ren,Xin Wei,Song-Tao Wei,Fei-Yu Wang,Jing Wang,Jia-Zhuang Xu,Lu Xu,Rizwan M. Gul,Zhong-Ming Li
Background Synovial fluid components, especially lipids, can trigger oxidation of ultrahigh-molecular-weight polyethylene (UHMWPE) artificial joint components in vivo. The use of antioxidants such as vitamin E effectively diminishes the oxidative cascade by capturing free radicals and reducing the oxidation potential of UHMWPE implants. Using a thermo-oxidative aging method, we recently found that tea polyphenols can enhance the oxidation resistance of irradiated UHMWPE in comparison with commercial vitamin E. However, it is yet unknown whether tea polyphenols can reduce lipid-induced oxidation. Questions/purposes We explored whether tea polyphenol-stabilized UHMWPE would exhibit (1) lower squalene absorption; (2) stronger oxidation resistance; and (3) lower content of free radicals than vitamin E-stabilized UHMWPE under a physiologically-motivated in vitro accelerated-aging model. Methods Tea polyphenol (lipid-soluble epigallocatechin gallate [ ls EGCG]) and vitamin E were blended with UHMWPE powders followed by compression molding and electron beam irradiation at 100 and 150 kGy. Small cubes (n = 3, 60 mg, 4 × 4 × 4 mm 3 ) cut from the blocks were doped in squalene at 60°, 80°, 100°, and 120° C for 2 hours. Gravimetric change of the cubes after squalene immersion was measured to assess absorption. Thin films (n = 3, ∼60 μm) were also microtomed from the blocks and were doped at 120° C for 24 hours. Oxidation induction time (n = 3, 5 mg of material from the cubes) and incipient oxidation temperature (n = 3, thin films) were obtained to determine the oxidation stability. Signal intensity of the free radicals, obtained by electron spin resonance spectroscopy, was used to qualitatively rank the antioxidant ability of vitamin E and ls EGCG. Results Squalene absorption was comparable between ls EGCG/UHMWPE and vitamin E/UHMWPE at a given temperature and radiation dose. The oxidation induction time of 100 kGy-irradiated UHMWPE was increased with ls EGCG compared with vitamin E except at 120° C. For example, the oxidation induction time value of 100 kGy-irradiated ls EGCG/UHMWPE immersed at 60 o C was 25.3 minutes (24.2–27.8 minutes), which was 8.3 minutes longer than that of 100 kGy-irradiated vitamin E/UHMWPE which was 17.0 minutes (15.0–17.1 minutes) (p = 0.040). After squalene immersion at 120° C, the incipient oxidation temperature of 100 and 150 kGy irradiated ls EGCG/UHMWPE was 234° C (227–240° C) and 227° C (225–229° C), which was higher than vitamin E-stabilized counterparts with value of 217° C (214–229° C; p = 0.095) and 216° C (207–218° C; p = 0.040), respectively. The electron spin resonance signal of 150 kGy irradiated ls EGCG/UHMWPE was qualitatively weaker than that of 150 kGy irradiated vitamin E/UHMWPE. Conclusions ls EGCG-stabilized UHMWPE demonstrated higher oxidation resistance than vitamin E-stabilized UHMWPE after squalene immersion, likely because ls EGCG donates more protons to eliminate macroradicals than vitamin E. Clinical Relevance Our in vitro findings provide support that ls EGCG may be effective in protecting against oxidation that may be associated with synovial fluid-associated oxidation of highly crosslinked UHMWPE joint replacement components.
研究领域:
生物医学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Mei Chen,Yuming Chen,Wei Li,Peng Liang,Congjing Ren,Binbo Jiang,Jingdai Wang,Yongrong Yang
A facilely catalytic approach to prepare weakly entangled ultra-high-molecular-weight polyethylene (UHMWPE) with a fine particle size is reported with the polyhedral oligomeric silsesquioxane (POSS)-modified MgCl2-based Ziegler–Natta catalyst. CO in situ FTIR spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and N2 adsorption and desorption experiments revealed that the POSSs can coordinate with the MgCl2(110) plane, acting as adhesives with a cage structure to be in situ embedded into the MgCl2-based support. This in situ embedding of POSS facilitated the uniform dispersion of POSS nanoparticles, contributing the isolation effect for active TiCl4 sites in the molecular scale, thus synthesizing the weakly entangled UHMWPE with exceptional activities. Simultaneously, the MgCl2-based catalysts afforded UHMWPE particles with small sizes, where POSS-modified catalysts brought the UHMWPE particle size down to below 200 μm, thanks to their considerable activities. To the best of our knowledge, this is the first time that nascent UHMWPE with a less entangled state and a fine particle size was synthesized. This combination of structural advantages enables substantial improvements in the toughness/stiffness/strength balance of nascent UHMWPE, especially for the impact strength which can reach 113.6 kJ/m2 with a relatively low molecular weight.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
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IF 8.758
Binbin Dong,Yahao Guo,Shuangjie Sun,Hao-Yang Mi,Ping He,Maxwell Fordjour Antwi-Afari,Chuntai Liu,Changyu Shen
High-performance low-cost superhydrophobic sponges are desired for selective recycling of leaking oils from open water. Herein, an ingenious method is proposed to fabricate an ultrathin superhydrophobic coating layer on a commercial sponge. The coating layer is composed of a shish–kebab-structured porous ultrahigh molecular weight polyethylene (UHMWPE) film that is fabricated from a UHMWPE/xylene solution by shear flow-induced crystallization. A strong relationship between the shish–kebab crystallite morphology and the superwetting performance is confirmed. The UHMWPE coating layer fabricated at a 900 rpm rotation rate possesses a lamellae size of 95.1 nm and a lamellae distance of 27.4 nm, which lead to a high water contact angle of 157° and a low contact angle hysteresis of 4.5°. The UHMWPE layer prepared in 4 min of treatment is thick enough to prevent the intrusion of water even under vacuum and remain superoleophilic. The developed UHMWPE-coated sponge (UCS) exhibited a high absorption capability of 70–191 g/g toward various oils and solvents, which is comparable with the neat melamine sponge. Its excellent compressibility and durability enabled fast recovery of absorbed oil with a high recovery rate (over 85%) by mechanical squeezing. The UCS could be assembled into small devices to selectively collect oil from open water and a water/oil mixture using a pump, which manifests its promising practical applicability. Apart from these extraordinary properties, the approach developed has the lowest material cost and the shortest processing time hitherto.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 37
·21371-21380
·
IF 3.049
Huaming Wang,Jingshi Cao,Fubin Luo,Changlin Cao,Qingrong Qian,Baoquan Huang,Liren Xiao,Qinghua Chen
The potential prospect of expandable graphite (EG) in the development of polymer composites is severely limited by required large additions and poor interface compatibility with the polymer. Inspired by mussels, polydopamine (PDA) can be used as an effective interface modifier for EG to prepare ultra high molecular weight polyethylene (UHMWPE) composites with superior mechanical properties and high flame retardancy. The surface of expandable graphite (EG) was coated with a thin adhesive PDA film through self-polymerization of dopamine. The modified expandable graphite (EG@PDA) was combined with APP to prepare UHMWPE flame retardant composites. Compared with UHMWPE/APP/EG (with 20 wt% APP/EG), UHMWPE/APP/EG@PDA (with 20 wt% APP/EG@PDA) gives a decrement by 16.7% in limiting oxygen index, 29.7% in the peak of the heat release rate, 20.4% in total heat release and 49.3% in total smoke release, with an increment by 37% in tensile strength and 67.9% in elongation at break, respectively. It is suggested that the presence of PDA as an interface modifier can greatly improve the interfacial compatibility between EG and UHMWPE. Moreover, it can lead to forming more char residue and reducing the release of smoke particulates during combustion of the composites.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Soft Matter
·
2023
·Vol. 19
·期 29
·5459-5467
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IF 3.4
Yang Sui,Yi Cui,Peng Wei,Chuanbo Cong,Xiaoyu Meng,Hai-Mu Ye,Qiong Zhou
Considering the molar mass between entanglements to be an intrinsic property of ultra-high molecular weight polyethylene (UHMWPE), the number of entanglements per chain increases with increasing molar mass, correspondingly making the UHMWPE intractable. Herein, we dispersed TiO2 nanoparticles with different characteristics into UHMWPE solutions to disentangle the molecular chains. Compared with the UHMWPE pure solution, the viscosity of the mixture solution declines by 91.22%, and the critical overlap concentration increases from 1 wt% to 1.4 wt%. A rapid precipitation method was utilized to obtain UHMWPE and UHMWPE/TiO2 composites from the solutions. The melting index of UHMWPE/TiO2 is 68.85 mg, which is in sharp contrast to that of UHMWPE which is 0 mg. We characterized the microstructures of UHMWPE/TiO2 nanocomposites using TEM, SAXS, DMA, and DSC. Accordingly, this significant improvement in processability contributed to the reduction of entanglements and a schematic model was proposed to explain the mechanism by which nanoparticles disentangle molecular chains. Simultaneously, the composite demonstrated better mechanical properties than UHMWPE. In summary, we provide a strategy to promote the processability of UHMWPE without sacrificing its outstanding mechanical properties.
研究领域:
材料科学
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纳米技术
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聚合物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 43
·51261
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IF 3.125
Nouman Ali Shah,Yue Ren,Ri-Tong Lan,Jia-Cheng Lv,Rizwan M. Gul,Peng-Fei Tan,Shishu Huang,Lin Tan,Jia-Zhuang Xu,Zhong-Ming Li
Highly crosslinked ultrahigh molecular weight polyethylene (UHMWPE) stabilized by vitamin E (VE) is widely applied in artificial joints as the bearings. Despite the approval, there is a discord that VE lowers the crosslinking efficiency, limiting its use at high concentration. In this work, we aim to obtain highly crosslinked and oxidation resistant UHMWPE through the conjunction of tea polyphenol and chemical crosslinking. We hypothesized that highly incorporated tea polyphenol with multiple reactive sites can ameliorate crosslinking efficiency of chemical crosslinked UHMWPE in comparison to VE. Epigallocatechin gallate (EGCG) as representative tea polyphenol was incorporated into UHMWPE at high concentration (2–8 wt%), followed by chemical crosslinking with 2 wt% organic peroxide. Unlike VE/UHMWPE blends as the control, chemical crosslinking achieved an increasing trend in crosslink density of EGCG/UHMWPE blends with increasing antioxidant concentration. High concentration of EGCG also enhanced the oxidation stability of UHMWPE. Intriguingly, EGCG endowed UHMWPE with an excellent antimicrobial property, which was inefficient in VE/UHMWPE. Cell viability was hardly affected by the high loaded antioxidant and peroxide. The chemically crosslinked UHMWPE blended with EGCG is proved to be a reasonable, cost effective and realistic alternative for use in artificial joints.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2024
·Vol. 45
·期 12
·11062-11075
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IF 4.8
Ramzi Makaoui,Oussama Mehelli,Djelel Eddine Tria,Larbi Hemmouche,Abdelmalek Habes,Mehdi Derradji
In this research, an investigation was conducted to ascertain the impact of boron carbide (B 4 C) microparticles on soft and hard armor configurations, utilizing two distinct high-performance fabrics namely, Kevlar and Ultra-high Molecular Weight Polyethylene (UHMWPE), also this work discerned the optimal fabric for protection against dagger attacks and 9 mm full metal jacket (FMJ) projectiles. Initially, rheological tests on four shear thickening fluid (STF) samples revealed that 70% of nano-silicate (SiO 2 ) content was the optimal ratio. Besides, scanning electronic microscope (SEM) tests showed that B 4 C affected the nano-silicate dispersion. Hence, the use of STF as a matrix, led to complete protection in low-velocity stab test and behavior improvement when subjected to NIJ ballistic test for both fabric types. On the other hand, the dynamic mechanical analysis (DMA) of the thermosetting epoxy resin-based composites reinforced by B 4 C indicated that the 10% ratio offered maximum rigidity, resulting in improved ballistic performance. This study revealed that Kevlar fabrics exhibit superior behavior in soft protection, while UHMWPE hard composite display further rigidity against high-velocity impacts. Overall, this work contributes novel insights into the efficiency of B 4 C integration within soft and hard armor configurations using two ballistic fabrics, highlighting their performance characteristics in ballistic shielding. Highlights Investigation of B 4 C microparticles: The research examines the impact of B 4 C microparticles on soft and hard armor configurations. High-performance fabrics: Kevlar and UHMWPE uses. The use of STF as a matrix for soft and thermosetting epoxy resin for hard armor: enhanced composite performance. Low-velocity and high-velocity impact tests investigations; microparticles B 4 C incorporation: superior mechanical characteristics. Remarkable energy absorption: promising shielding uses.
研究领域:
材料科学
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防护工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2025
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IF 4.7
Yonggang Guo,Yunfei Wu,Jiangbo Peng
In this study, a novel composite material has been prepared, which is composed of ultra-high molecular weight polyethylene (UHMWPE) with a small amount of polyimide (PI). The friction behavior of composites under dynamic speed and load conditions was investigated using a MDW-02G friction and wear testing machine. The frictional behavior of composites under low-speed with heavy-load (LSHL) dry friction and high-speed with light-load (HSLL) water lubrication conditions was studied separately. The tribological performance of the composites was analyzed on the basis of the coefficient of friction, wear rate, and wear morphology. The experimental results showed that the addition of PI enhances the thermal stability of UHMWPE-based composites. The defects of the UHMWPE surface vulnerable to fatigue wear under extreme working conditions were improved. Compared with UHMWPE, the wettability of PI modified composites was enhanced, and the lubricating film formed could better adhere to the friction interface. This effectively improved the lubrication conditions between the friction interfaces, while improving the wear resistance and reducing the coefficient of friction. It can be concluded that the thermal stability and wear resistance of UHMWPE-based water-lubricated bearings can be improved by a small proportion of PI enhancement, while ensuring that the composite material also has good self-lubricating properties. Highlights Low PI content enhances the thermal properties and wear resistance of composites. Under LSHL conditions, the wear rate in the composite can decrease by up to 93%. The wear mechanism of composites under LSHL and HSLL conditions was revealed.
研究领域:
材料科学
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摩擦学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 44
·e56190
·
IF 2.7
Shifan Li,Conglin Dong,Chengqing Yuan,Xiuqin Bai
Marine water-lubricated bearings have the advantages of environmental friendliness and long replacement cycle. However, when under the complex lubrication circumstance, the frictional and vibrational behaviors of water-lubricated bearing always dissipate the mechanical energy output from the ship's diesel engine. Aiming at this problem and combining with previous research findings, in this paper, ceramic balls with similar mechanical properties to ship's main shaft were selected as the friction counterpart to simulate the operating conditions of marine water-lubricated bearing. Meanwhile, dual nanoparticles of tungsten disulfide (WS 2 ) and titanium dioxide (TiO 2 ) were used to modify ultra-high molecular weight polyethylene (UHMWPE) bearing material. The tribological and vibrational properties of the prepared composites were carefully investigated. The results showed that compared to pure UHMWPE, with the synergistic effect of 0.75 wt% WS 2 and 0.9 wt% TiO 2 , the frictional and vibrational behaviors of the composites were reduced by 43.3% and 42.7%. Mechanical testing and microscopic characterization revealed the enhancement mechanism of these nanoparticles on UHMWPE. This study proposed a design strategy on marine water-lubricated bearings for engineering application.
研究领域:
材料科学
·
机械工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）