MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·Vol. 44
·期 10
·2200971
·
IF 4.6
Jie Mao,Jing Li,Wang Lin,Faliang Luo
This work describes an easy and effective process for preparing a homogeneous polybutadiene (PB) dielectric elastomer with improved actuated strain by utilizing a photochemical thiol-ene click reaction. The carboxyl groups and various ester groups are used for grafting on the PB. Since the length of the alkyl chains of the ester groups will significantly influence the polarities of the carbonyl groups and hydrogen bonding effect, the influence of polarity and hydrogen bonding effect on the dielectric properties and mechanical properties of the modified polybutadienes is carefully discussed. Very interestingly, it is found that the increment of dielectric constant of PB modified by carboxyl groups is the lowest one compared to other modified PBs with the ester groups. Meanwhile, the modified PBs with the ester groups could achieve pretty low dielectric loss factor, and finally, a high dielectric constant (3.6), low dielectric loss factor (0.0005), and large actuated strain (≈25%) of the modified polybutadienes could be achieved by the modified PBs with butyl acrylate groups. This work provides a simple and effective method for the designing and synthesizing of a homogeneous high electromechanical performance dielectric elastomer with high dielectric constant and low dielectric loss.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 60
·期 15
·2371-2382
·
IF 3.046
Di Zhou,Bai-Heng Wu,Wen-Wu Yang,Xiao Li,Liang-Wei Zhu,Zhi-Kang Xu,Ling-Shu Wan
The breath figure (BF) process has been widely used to prepare patterned porous films. The mechanism remains to be further elucidated, especially how polymer architectures affect the stability of water droplets and the pore structure. Polystyrenes (PS) was functionalized with a series of polar groups both in chain middle and chain end, which was synthesized by using difunctional atom transfer radical polymerization (ATRP) initiators with the combination of nucleophilic substitution of the end bromine. It is found that PS with polar groups, which help to reduce interfacial tension, tends to form regular patterns at low concentration and to generate multilayered pores. The coalescence resistance measurement was performed to characterize the stabilization of water droplets from polymers by precipitation. The results show opposite trend with the results of the BF process, indicating a minor role played by polymer precipitation on microdroplets stabilization. We reveal that addition of only an oxyethyl group in the chain middle of PS contributes to the formation of ordered patterns. This study helps to shed light on the impact of polymer architectures on the self-assembly behavior in the BF process. Graphical
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Xueying Liu,Weibo Li,Yingjie Jiang,Nanying Ning,Ming Tian
Dielectric elastomer generators (DEGs) based on silicone rubber composites have received considerable attention in recent years. However, the addition of traditional rigid dielectric fillers not only increases the modulus of composites but also leads to interface debonding between the filler and elastomer matrix under high stretching conditions, thereby limiting the energy harvesting performance. Here, gel-like ester group grafted butadiene rubber (GEBR) with a relatively low modulus was synthesized and used as a “soft filler” to enhance energy harvesting performance of PMVS-based DE composites. The GEBR filler with a high concentration of polar groups could lead to an increase in the dielectric constant of GEBR/PMVS composites by the introduction of interfacial polarizability and the improvement of dipole polarizability. Most notably, compared with TiO2 as the rigid filler, the combination of GEBR's deformability under stretching and strong interfacial interaction between the GEBR filler and PMVS matrix could effectively prevent weak interface formation under high strain conditions, and thus hinder the propagation of electrical treeing. As a result, benefiting from the GEBR filler with a low modulus, 5 vol% GEBR/PMVS DEG exhibits an excellent maximal energy density (65.4 mJ g−1) and outstanding power conversion efficiency (38.4%), achieving a high energy density at relatively low input mechanical force. This study presents a pioneering methodology to fabricate high-performance all-organic DE composites for DEGs through designing a soft dielectric filler with exceptional deformability under stretching.
研究领域:
材料科学
·
能源技术
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2025
·Vol. 192
·期 3
·1-14
·
IF 5.3
Zhang Yiwen,Zhao Chenyang,Yan Wen,Tian Tian,Zhao Min,Zhao Longshan
Carbon quantum dots (CQDs) were synthesized from brominated 1-hexadecyl-3-vinylimidazolium and citric acid, and a mixed-mode chromatographic (MMC) stationary phase, which can be used in the RPLC/HILIC/IEC chromatographic modes with a good separation efficiency, was successfully synthesized by click-chemistry bonding to a sulfhydryl-modified silica surface. The successful synthesis of the chromatographic stationary phase was demonstrated by its characterization. The effects of organic phase ratio, column temperature and buffer salts on the column were investigated, established the van’t Hoff equation, and verified the ion-exchange effect of the column by separating benzoic acid and phenolic compounds under different pH conditions. The reversed-phase performance of the column was characterized by Tanaka test. Compounds such as alkylbenzenes, polycyclic aromatic hydrocarbons, and nucleosides can all be separated on the column in a short period of time. The reproducibility and stability of the columns were verified under the corresponding chromatographic conditions, and the results showed good reproducibility and stability of the columns. The chromatographic column was used to separate the base nucleosides in apples, and four base nucleosides were successfully isolated from apples. Graphical
研究领域:
分析化学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
TRIBOLOGY LETTERS
·
2018
·Vol. 66
·期 4
·1-11
·
IF 2.182
Ji Min,Liu Shuhai,Xiao Huaping
In this study, impacts of four types of monoglycerides and four types of triglycerides, which serve as additives, on properties of water-based drilling mud were explored using a ball-on-disk tribometer. It was found that the addition of glycerides increased the viscosity of drilling mud slightly. The results of tribological experiments indicate that carbon chain length, level of unsaturation, and polar groups of additives are three key factors which determine friction reduction and anti-wear behaviors of the drilling mud. The formation of a denser and thicker protective film on steel surface due to presence of glycerides additives is attributed to observed better friction reduction behaviors.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Ningning Yin,Jianxiong Chen,Fuhao Ren,Xiaorong Dou,Lijun He,Jie Mao
Increasing the polarity of molecular chains is the key to achieving high energy density in polymers. However, the polarization capability of polymers is not merely an accumulation of monomer dielectric properties. A pressing need arises for a universal design concept to guide the development of all-organic dielectric films, extending from monomer molecular structure to the polymer cross-linking network. In this research, we have developed a flexible dielectric film with a high energy density. The reduction of rotational space hindrance for polar functional groups ensures the polymer's heightened polarity. Additionally, the staggered arrangement of ester groups and benzene rings, combined with cross-linking constraints, alleviates the decrease in insulation performance caused by the planar conjugation of benzene rings. Significantly, the adjustment of the cross-linking network effectively mitigates the high conduction and polarization losses associated with enhanced polarization. The reduced interchain spacing contributes to lowering the average charge mobility, thereby restricting charge movement. Surprisingly, the polymer film exhibits a high breakdown strength of 770 MV/m and an ultra-high discharge energy density of 16.7 J/cm³. This surpasses the levels observed in traditional polymer dielectric films, emphasizing the potential impact of molecular structure design and polymer cross-linking networks in advancing high-performance polymer dielectrics.
研究领域:
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2022
·
IF 6.206
Yufeng Liang,Lipeng Wang,Yongping Bai,Haiyan Qian,Huifang Xu,Yu Wang
UV-cured releasing agent is a new type of anti-fouling coatings, which must meet needs of the development in the pressure-sensitive adhesive industry, but also in line with modern environmentally friendly demands. With a step-by-step method, a multi-functional photosensitive silicone modified polyurethane releasing agent was synthesized using a hydroxyalkylsiloxane, toluene diisocyanate, and pentaerythritol triacrylate, carrying out by UV initiating technique to prepare the releasing films. The infrared spectrum and the nuclear magnetic resonance spectrum were used to analyze a molecular structure of the releasing agent. Peel strength tests and morphological tests were used to characterize the application capabilities of the releasing films. X-ray photoelectron spectroscopy and other techniques were simulated the migration of the surface group of the releasing films during the pressure sensitive adhesive adherence. The results showed that the excessive soft segment silicone chain reduced crosslink density, thereby reducing the residual performance, while the excessive polar group density would simultaneously reduce the releasing performance and residual performance. This conclusion reveals the releasing mechanism of the UV-cured releasing agent, and provides an important guiding significance for the molecular design and product development of the new type of releasing agent.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2022
·
IF 9.417
Junsen Ma,Long Jiang,Yi Dan,Yun Huang
To explore relationship between the inter-laminar shear properties and the interfacial structure of carbon fiber (CF) reinforced epoxy resin (EP) composite materials (CFRPs), four CFRPs with different interfacial structures were prepared through introducing polar groups on the surface of the CF and then combining the modified CF with the EP, including CF/EP (where no polar group was introduced), CF-COOH-EP (where carboxyl group –COOH was chemically introduced), CF-COOH/MXene /EP (where –COOH was chemically introduced while MXene was physically introduced and the MXene was non-covalently bonded to CF and to EP), and CF-CONH-MXene-EP (where both of –COOH and MXene were chemically introduced and the MXene was covalently bonded to CF and to EP). Results of inter-laminar shear strength (ILSS) of the materials and morphology of transverse and longitudinal cross-sections of the damaged materials show that with enhancing the interfacial interaction between CF and EP, the ILSS increases and the interlayer shear failure gradually changes from a single interface debonding (for CF/EP) to a combination of interface debonding and matrix fragmentation. The interfacial structure of CF-COONH-MXene-EP with higher interfacial interaction could bear more interlayer shear forces, being beneficial for improving the service life of CFRPs.
研究领域:
材料科学
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2022
·
IF 5.204
Zeming Fang,Xueyi Yu,Yijing Qin,Dan Li,Qianfa Liu,Dong Lu,Ke Wang
Deterioration of the low-loss property of substrate materials significantly affects the service life of high-frequency and high-speed circuits. In this work, the effect of short-term thermal aging on the microwave dielectric property of thermosetting polyphenylene oxide/hydrocarbon resin was investigated. Dielectric and dynamic thermo-mechanical spectra were used to evaluate changes in polar structure and crosslinking structure over the aging process. Infrared spectroscopy was applied to monitor the evolution of chemical structure, and the changes in microwave dielectric properties at 10GHz were recorded. An apparent linear relationship was discovered between the polar group accumulation in the superficial layer and the change in microwave dielectric loss factor. Finally, the effect of aging on moisture absorption and the influence of thickness on the aging rate were preliminarily examined to investigate the impact of aging on practical applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2023
·
IF 6.4
Jiajun Xu,Shiai Xu,Junzhe Hao,Hailian Cao
Good adhesive strength and joint durability are necessary for aluminum (Al)/polymer laminated film for lithium-ion battery packages. A modified propylene-based elastomer (mPBE) was prepared as the inner adhesive in this study. The polar group was grafted onto the PBE molecular chain via melt grafting with the assistance of styrene. The adhesive performance of PBE modified with glycidyl methacrylate is significantly higher than that of commercially available inner adhesives, Mitsui A and Dupont 739. Moreover, environmentally friendly trivalent chromium [Cr(III)] chemical conversion was used to treat Al foil and improve the adhesive joint. The wettability behavior of adhesive melt on the surface of Al foil was studied using high-temperature contact angle testing. The results indicate that wettability is not the sole factor impacting interfacial strength, surface energy of the adhesive melt also plays a role. To further study the effect of polar groups on the mPBE adhesion, a solvent casting-evaporation method was developed to prepare an ultra-thin mPBE coating on the Al foil surface. The morphology of mPBE-coated Al foils and the thickness of the coating were studied by atomic force microscope. The bonding mechanism at the interface was studied through time-of-flight secondary ion mass spectroscopy, and it was shown that the Cr(III) conversion coating could react with polar groups via acid-base interaction. Moreover, quantum chemical calculations based on density functional theory were used to reveal the bonding mechanism at the molecular level, and it is found that the adhesive strength is related to the electron-donor abilities and reactivity of the adhesive molecules.
研究领域:
材料科学
·
表面化学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Jiapeng Wang,Sen Cheng,Xinyu Wang,Jiabao Wang,Chunhua Lu,Kai Guo,Ning Zhu,Xin Hu
Poly(vinylidene fluoride) (PVDF)-based polymers are considered to be one of the most promising candidates for high-density capacitors. However, the practical application is limited by their low charge–discharge efficiency (η), which is ascribed to the high remnant polarization arising from the large hysteresis loss and conduction loss. In this work, we designed and prepared all-polymer-based dielectrics from cross-linking poly(vinylidene fluoride-hexafluoropropylene)-graft-poly(glycidyl methacrylate) (P(VDF-co-HFP)-g-PGMA, V–H–G) to address the issue. The bio-based amine of 2,5-bis(aminomethyl)furan (BAMF) was utilized to generate cross-linked networks through the amino-epoxy reaction. It demonstrated that the cross-linked structures, rich in polar groups and hydrogen bonding, could effectively tune the crystal properties and impede electrical conduction at high fields and elevated temperatures, resulting in restrained remnant polarization. An improved energy density of 7.39 J·cm–3 at 450 MV·m–1 for the cross-linked polymer was achieved, which was 648% of P(VDF-co-HFP) (V–H) (1.41 J·cm–3 at 300 MV·m–1) and 140% of V–H–G (5.18 J·cm–3 at 400 MV·m–1). Moreover, the η was significantly improved from 32% for V–H and 60% for V–H–G to 73.2% for the cross-linked polymer. Additional advantages of better dielectric properties at elevated temperatures compared with V–H and V–H–G were also observed. This work would provide inspiration for the design and preparation of high-performance polymer dielectrics.
研究领域:
材料科学
·
电气工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Fang-Wei Ling,Ming-Chao Luo,Mo-Kun Chen,Jian Zeng,Shi-Qi Li,Hong-Bo Yin,Jin-Rong Wu,Yun-Xiang Xu,Guangsu Huang
Non-covalent interactions imposed by polar groups affect the properties of polyisoprene in various ways. But traditional modification method only led to randomly functionalized product which ignored the effects of sequence and location of polar groups. In this work, by using a novel polar monomer hydroxyl-myrcene (HMY), hydroxyl group terminally (BC–OH) and randomly functionalized (RC-OH) polyisoprene copolymers were successfully obtained. Due to the different hydroxyl group sequences, BC-OH and RC-OH shows different morphologies and rheological properties. Furthermore, polyhedral oligomeric silsesquioxanes (POSS) with urea bond was used as nanofiller to attach on BC-OH and RC-OH and generating BC-POSS and RC-POSS, respectively. The assembly of POSS and the formation of urea hydrogen bond will occur collaboratively. As a result, BC-POSS and RC-POSS showed distinct morphological properties and thermal stabilities . It is found that ordered urea bonds were formed in RC-POSS, while less ordered urea bonds were formed in BC-POSS. Overall, these results suggest that the tailoring of polar group sequence in polyisoprene copolymers could be a promising avenue for tuning polyisoprene performance via tuning aggregation behaviors of the polar groups.
研究领域:
高分子化学
·
材料科学
·
大分子化学
·
纳米技术
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）