JOURNAL OF ELECTRONIC MATERIALS
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2019
·Vol. 48
·期 5
·2745-2753
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IF 1.676
Zhan Haijiao,Guo Jiayu,Shen Jiali,Wang Xiaorong,Fan Zhonghua,Guo Bing,Liu Wei,Shen Hangyan
Silver microparticles have inspired much research interest due to their enhanced properties for use in optical, electric, catalytic, and magnetic applications. One such use is as electrically conductive filler for printed electronics. A manufacturing approach has been developed to prepare low-curing-temperature silver pastes. Firstly, silver flakes were synthesized directly by a one-step aqueous-phase reduction reaction, using silver nitrate as silver salt precursor and iron(II) sulfate heptahydrate as reducing agent. Various silver flake samples were synthesized by controlling experimental parameters such as the reaction temperature, surfactant concentration, and reducing agent concentration. The obtained silver powders were characterized by x-ray diffraction analysis, scanning electron microscopy, and dynamic light scattering measurements. The results revealed that the morphology of the silver powders was a plate-like structure with diameter of 1 μ m to 1.5 μ m and thickness of 30 nm. The prepared silver flakes were then used directly without ball milling to prepare low-curing-temperature silver pastes. The bulk resistivity of a line screen-printed using silver paste containing 48 wt.% (34 ± 5 vol.%) silver flakes and cured at 140°C for 30 min in air was about (1.773 ± 0.118) × 10 −6 Ω m. More importantly, the prepared screen-printed patterns exhibited excellent durability in terms of peel strength and folding endurance.
研究领域:
材料科学
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纳米技术
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电子工程
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应用化学
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先进制造
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
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2024
·
IF 8.9
Linhan He,Kaili Ling,Mingjie Wang,Xuejin Zhang,Jing Li,Yao Chen,Yongming Fan
This study highlights the significance of the difference between the melting and solidification temperatures of phase change materials (PCMs) in their practical applications. We incorporated the wood fiber as a support phase and used alkylation to modify the pore structure and surface properties of silica aerogels . The effect of different pore size distributions and surface properties on the phase change properties of PCMs was investigated. The results showed that nanopores increased pressure and the melting point of PCMs while the weak interaction force on the substrate surface decreased their solidification temperature. Furthermore, using matrices with unique properties, such as mesopore and hydrophobic aerogels , proved to be effective in reducing the difference between the melting and solidification temperatures by up to 44.1 % compared to pure paraffin wax. Moreover, hydrophobic groups enhanced the encapsulation performance of the composite, effectively isolating the influence of water.
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
COMPOSITES PART B-ENGINEERING
·
2020
·
IF 7.635
Shuang Yang,Siqi Huo,Jun Wang,Bin Zhang,Jingsheng Wang,Shiya Ran,Zhengping Fang,Pingan Song,Hao Wang
The design of highly fire-safe and smoke-suppressive single-component epoxy (EP) resins combining modest curing temperature and fast curing rate has been desirable yet very challenging in both academia and industry. Herein, we report a facile design of a phosphorus/imidazole-containing single-component EP system via incorporating 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and a flame-retardant curing agent cyclotriphosphazene-modified benzimidazole (BICP) into EP. Our results show that EP/DOPO/BICP exhibits a rapid modest-temperature curing feature because DOPO serves as a switch that triggers BICP to release benzimidazole (BIM) via substitution reaction in the initial curing stage. Moreover, as-prepared EP/DOPO/BICP shows outstanding fire retardancy, reflected by the high limited oxygen index (LOI) of 38.3% and UL-94 V-0 rating. Compared to the control EP system, the peak of heat release rate (PHRR) and total smoke production (TSP) of EP/DOPO/BICP remarkably decrease by ~74.5% and ~50.6%, respectively, which is superior to previously-reported flame-retardant P-containing epoxy counterparts. The significant enhancements in flame retardancy and smoke suppression are mainly due to the formation of a highly intumescent char layer and the reduced burning degree of pyrolysis fragments. This work offers a facile and scalable strategy for creating fast-curing, modest-temperature curable, highly fire-resistant and smoke-suppressive one-component epoxy systems applicable to large-scale industrial production.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2020
·Vol. 6
·期 12
·125358
·
IF 1.929
Chao Huang,Fangfang Niu,Guangxia Xie,Jinhui Li,Changqing Li,Ying Wang,Fei Ji,Guoping Zhang,Rong Sun,Ching-Ping Wong
Polyimide (PI) with excellent mechanical, thermal, dielectric properties which has been widely applied in electronics, automotive, high-speed rail and chemical industrie. However, the high curing temperture has limited its application in the micro-electronic areas. To address this issue, quinoline (QL) with uique catalytic effect was employed in low temperature curable PI. The changes in chemical structure of the PI films at different temperature was confirmed by FTIR spectroscopy with controlled addition of QL. The effects of QL content on the electrical, thermal and mechanical properties of polyimide were discussed as well. It was found that PI-1.5 has been proved with the best property which exhibited high imidization rate of 99.6% at 200 °C, dielectric constant of 3.20 and a dielectric loss of 5.06 × 10−3 (1 MHz). Besides, the Young's modulus of as much as 1.66 GPa, elongation at break of more than 145% with high tensile strength about 134 MPa have been achieved. Moreover, the T5 is more than 545 °C and the glass transition temperature is higher than 376 °C. The developed low temperature curable PI is expected to be applied in the advanced electronic packaging such as fan-out wafer package, insulation, interlayer dielectric and so forth.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2019
·
IF 1.584
Xianfeng Que,Zhiming Qiu,Yurong Yan
Benzocyclobutene (BCB) resins have aroused much interest because of their excellent physical and chemical properties. Unfortunately the temperature required to induce cross-linking in typical BCBs is higher than 250°C, which restricts their applications. In this study, a novel cyano-containing BCB-terminated imide monomer was synthesized through the reaction of 1-cyano-5-amino-benzocyclobutene with 4,4′-oxydiphthalic anhydride. This monomer allows a 50–100°C lower curing temperature in comparison with typical BCBs, and it is highly soluble in various solvents and can easily convert to cured film at 150–200°C. Because of the presence of rigid imide group and strong polar cyano group, the cured film exhibits excellent mechanical strength with tensile strength up to 87.8 MPa, high glass transition temperature up to 350°C, low coefficient of thermal expansion (36.9 ppm K−1), and outstanding planarity with the average surface roughness as low as 0.26 nm.
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
MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Chuntao Li,Junfeng Wei,Mincong Chen,Xiaoxiao Guan,Xi Yang,Zhenghui Li,Chunping Ma,Xiaoji Ye
To avoid the health risks of Cr 6+ in traditional Dacromet coatings, developing chromium-free zinc-aluminum coatings attracts increasing attention in recent years. However, the state-of-the-art chromium-free zinc-aluminum coatings always have very high sintering temperatures over 250 °C, causing serious energy consumption. In the present work, for the first time, we report the fabrication of a novel chrome-free zinc-aluminum coating based on polysilazane. The results show that the polysilazane forms crosslinking structure via Si–O–Si backbones and the equilibrium anticorrosion effect can be achieved with a very low curing temperature less than 130 °C, which is much lower than current zinc-aluminum coatings. The zinc/aluminum particles present unique layered structure that are tightly contacted with the substrate, forming a dense structure with good barrier protection. Electrochemical characterization reveals that the coating exhibits capacitive impedance behavior at the initial stage of immersion test, indicating excellent shielding effect. As the immersion time increases, the activation corrosion of metal powder occurred under the action of corrosion medium, which plays a sacrificial anode protection role, and the resulting corrosion products can play certain shielding effect. Owing to above structural merits and electrochemical features, the developed chrome-free zinc-aluminum coating based on polysilazane demonstrates a superior corrosion resistance .
研究领域:
材料科学
·
表面工程
·
防腐蚀技术
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2025
·
IF 4
Jing Yichen,Lu Yin,Zhang Kan
It is well-established that the oxazine ring in benzoxazine resin generally exhibits good stability at ambient temperature, but undergoes ring-opening polymerization reactions at relatively higher temperatures. To make benzoxazine resin more practical for application, it is crucial to lower its curing temperature. In this study, novel thermosetting systems were prepared by using bio-based benzoxazine derived from daidzein (Dz-fa) blending with commercialized novolac resin. Novolac resin, which contains rich phenolic hydroxyl groups, was utilized as the curing accelerator for Dz-fa. The curing behavior of the thermosetting blends as well as the properties of the resulting thermosets was systematically investigated. The curing kinetics of the bio-based benzoxazine with novolac resin were monitored using differential scanning calorimetry and in situ FTIR spectroscopy. The thermal properties of the cured resins were assessed by thermogravimetric analysis and dynamic mechanical analysis. The flexural strength of materials is tested by universal material testing machine. These results demonstrated that employing the novolac resin effectively reduced the curing temperature of the bio-based benzoxazine without sacrificing too much in terms of the thermal stability and mechanical property. Specifically, the char yield of cured resin (Yc), the glass transition temperature ( T g ) and flexural strength of Dz-fa and novolac resin blends in the ratio of 9:1 were found to be 65.0%, 314 °C and 84.05 MPa, respectively. This study provides a practical approach to lowering the curing temperature of benzoxazine resins. The thermosets with relatively high thermal stability can be achieved through implementable process, thereby potentially reducing overall costs during the production of benzoxazine-based materials.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Fengjun Chen,Yifen Xu,Aying Wang,Zhongxiang Xia,Lidong Zhang,Lixian Yin,Zhi Wang
Polybenzoxazine resins are a new type of high-performance thermosetting resins with excellent properties. However, their high curing temperature significantly limits their applications. In this study, precursor catalysts with high catalytic efficiency were prepared using different transition metal nitrates and acetylacetone. Leveraging the principle of the combustion synthesis method, we successfully reduced the curing temperature of benzoxazine while simultaneously enhancing its mechanical and anticorrosive properties. The results demonstrated that this approach lowered the initial curing temperature of fluorinated benzoxazines to below 100 °C and significantly improved their adhesion and hardness, achieving ratings of 5B and 6H, respectively. In addition, the impedance modulus of the Ga(NO 3 ) 3 /AcAcH/benzoxazine system reached 2.17 × 10 5 Ω cm −2 , while the In(NO 3 ) 3 /AcAcH/benzoxazine system exhibited an impedance modulus of 7.45 × 10 4 Ω cm −2 , significantly enhancing corrosion resistance compared to the pure benzoxazine coating. The In(NO 3 ) 3 /AcAcH/benzoxazine system ultimately formed a heterogeneous domain structure. In contrast, the Ga(NO 3 ) 3 /AcAcH/benzoxazine system resulted in a homogeneous domain structure with minimal free volume. This study presents a novel and efficient strategy for reducing the curing temperature and improving the mechanical performance of benzoxazine, offering a simple yet effective catalytic approach with potential for applications in anticorrosion coatings.
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
MACROMOLECULES
·
2024
·
IF 5.1
Haiyang Zhang,Yang Wu,Meiqin Tian,Ting Zhao,Zekun Zhao,Jian Liu,Tingting Dong,Qingbao Guan,Zhengwei You
Liquid crystal thermosets (LCTs) terminated with a phenylethynyl group (PEPA) have attracted extensive attention because their tunable processability is superior to thermoplastic liquid crystal polyarylates (LCPs). However, the high curing temperature and low curing rate of PEPA restrict regulation on the performance of cured LCTs. To address above challenges, the bis- or mixed end-cappers with inner and outer ethynyl groups were utilized to terminate LCP. The curing temperature was decreased from 370 to 320 °C by introducing high reactive 3-ethynylaniline (EA) and derivatives as end-cappers. Meanwhile, the cured LCT exhibited a high storage modulus (∼30 MPa) at a rubbery plateau (400 °C) due to a highly cross-linked network (cross-linking density = 3131.9 mol·m–3). Moreover, appropriate mixed end groups could realize a similar curing rate (∼500 Pa·s·min–1) to their highly reactive counterparts. Consequently, rheological measurements were innovatively conducted to understand the curing mechanism of diverse end cappers, which would inspire new strategies to develop high-performance thermosets.
研究领域:
材料化学
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 23
·48783
·
IF 2.188
Zhongqi Liu,Yanchun Huang,Shifeng Deng
A novel polyacetylene-terminated silicone (PTS) resins possessing low curing temperature and high heat resistance has been prepared by Grignard reaction using m -diacetylenylbenzene (DEB), 1,3,5-triacetylenylbenzene(TEB), and dichlorosilane as original materials. The reaction of the functional groups was characterized by in situ Fourier transform infrared spectrometer. The experimental results indicated that Si─H and C≡CH bonds are almost exclusively involved in the crosslinking reaction, while ─C≡C─ bonds only partially react. Further, Si─H and C≡CH bonds can participate in the curing reaction at relatively low temperatures, but ─C≡C─ bonds require higher temperature, indicating the higher activity of Si─H and C≡CH bonds than ─C≡C─ bonds. As determined by differential scanning calorimetry, PTS resins have low peak exothermic temperature at 184.5 °C, which is lower than MSP resin (~ 210 °C); in addition, rheological test showed that PTS resins have a very wide processing window from 40 to 163.3 °C, indicating that the PTS resins have excellent processability with a low curing temperature and wide processing window. What is more, TGA results of thermal-cured PTS resins revealed that T d5 (5% weight loss temperature) of PTS-H10 reached the highest of 684.4 °C. Compared with PTS-H0 resin, there is an increase of 124.2 °C and the remarkably increased heat resistance correlated with a higher m -DEB input ratio. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48783.
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
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 3.7
Xing Yun,Kewen Zhang,Zhaojun Chu,Beitao Liu,Yan Kou,Xigao Jian,Zhihuan Weng
Heteroatom-doped porous carbon materials have been widely studied due to their high specific surface area and high heteroatom content, but it is difficult to achieve high specific surface area and high heteroatom content at the same time. Herein, a simple method is introduced to prepare N/O co-doped hierarchical porous carbon materials (DNZKs). Phthalonitrile resins (DNZs) were prepared by using 1,3- bis (3,4-dicyanophenoxy)benzene as raw material and ZnCl 2 /urea as composite curing agent, and then using KOH as activator to successfully prepare DNZKs with high specific surface area, developed pores and high N/O content. The porous carbon material (DNZK@400) obtained at a curing temperature of 400 °C has the highest N content (4.97% (mass)), a large specific surface area (2026 m 2 ·g –1 ), a high micropore proportion (0.9), a high O content (7.53% (mass)), and the best specific capacitance (up to 567 F·g –1 at 0.1 A·g –1 ), which can be attribute to the high temperature resistance of the nitrogen-containing aromatic heterocyclic structure in DNZs. When the mass ratio of resin and KOH is 1:1, the specific capacitance of the sample tested by the acid three-electrode system is obtained, and it is found that the material has high cycling stability (119% specific capacitance retention after 100,000 cycle tests). This work proposes a simple and easy-to-operate method for the preparation of multifunctional porous carbon.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2024
·Vol. 15
·期 37
·3779-3786
·
IF 4.1
Yin Lu,Jiaqi Wang,Yi Yang,Yichen Jing,Kan Zhang
In this work, a molecular design strategy by incorporating nitrile into ortho-amide benzoxazines was employed for achieving promising high performance thermsosets. We conducted a systematic investigation into the influence of additional nitrile moieties on the properties of ortho-amide benzoxazines. Initially, structural characterization of benzoxazines was performed using NMR and FT-IR spectroscopy, followed by DSC analysis and in situ FT-IR spectroscopy to study the polymerization mechanisms of each benzoxazine monomer. Notably, the thermoset derived from ortho-amide benzoxazine bearing two nitrile groups exhibited exceptional thermal stability (Td5 of 392.5 °C) and high glass transition temperature (Tg of 331 °C), alongside preferable flame retardancy (THR = 3.9 kJ g−1).This approach resulted in a new series of thermosetting resins with low curing temperature and improved comprehensive properties, thereby offering significant potential for the development of advanced thermoset materials with a wide range of intelligent applications.
研究领域:
材料科学
·
高分子化学
✓ 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）