Materials
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2021
·Vol. 14
·期 6
·1402
·
IF 3.623
Yi Zeng,Yiwu Liu,Jinghua Tan,Jie Huang,Junjie Liu,Ao Tang,Chengliang Chen,Hong Chen
In order to meet the increasingly stringent requirements for heat resistance and barrier properties in the packaging and electronic device encapsulation field. A high-barrier polyimide (NAPPI) contains naphthalene ring and amide group was prepared by polymerization of a novel diamine (NAPDA) and pyromellitic dianhydride. The structure and properties of diamine monomers and polymers were characterized. Results show that the NAPPI exhibits superior barrier properties with extremely low water vapor and oxygen transmission rate values of 0.14 g·m−2·day−1and 0.04 cm3·m−2·day−1, respectively. In addition, the NAPPI presents outstanding mechanical properties and thermal stability as well. This article attempts to explore the relationship between NAPPI structure and barrier properties by combining experiment and simulation. Studies on positron annihilation lifetime spectroscopy, Wide angle X-ray diffractograms and molecular dynamics simulations prove that the NAPPI has smaller interplanar spacing and higher chain regularity. In addition, the strong chain rigidity and interchain cohesion of NAPPI due to the presence of the rigid naphthalene ring and a large number of hydrogen bond interactions formed by amide groups result in compact chain packing and smaller free volume, which reduces the solubility and diffusibility of small molecules in the matrix. In general, the simulation results are consistent with the experimental results, which are important for understanding the barrier mechanism of NAPPI.Keywords:polyimide;naphthalene ring;amide group;barrier properties;molecular simulation
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
·
2021
·
IF 2.161
Manping Ma,Xiaotian Liu,Chuan Li,Qiaolong Yuan,Farong Huang
2,7-Diphenyloxynaphthalene with large conjugated structure has been introduced into the main chain of silicon-containing arylacetylene resin and then poly(dimethylsilylene-ethynylenephenoxynaphthyloxyphenylene-ethynylene) (m-PPNSA-MM) was synthesized. The m-PPNSA-MM resin shows good solubility and a wide processing window. A stable three-dimensional cross-linking network formed due to thermal crosslinking reactions of acetylene groups and intermolecular π–π stacking interactions after m-PPNSA-MM was cured through the process of 180°C/2 h + 220°C/2 h + 260°C/4 h. The flexural strength and modulus of the cured m-PPNSA-MM resin at room temperature are 49.2 MPa and 2.75 GPa, respectively. The cured m-PPNSA-MM resin show high thermal stabilities, the 5% temperature of weight loss (Td5) reaches 560°C in nitrogen.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2021
·
IF 4.43
Peng Wei,Hejuan Lou,Jinfei Yan,Longlong Li,Yifeng Zhang,Yumin Xia,Yanping Wang,Yimin Wang
In order to obtain thermotropic liquid crystal polymers (TLCP) with excellent comprehensive performance, naphthalene monomers (amount exceeding 50 mol%) of 6-hydroxy-2-naphthoic acid (HNA) and 2,6-naphthalene dicarboxylic acid (NDA) were used to prepare wholly aromatic TLCP with strong molecular interaction via “one-pot” melt polymerization method in this work. The structure and properties of the copolyesters were fully investigated by experimental measurements and molecular simulation . The simulation results indicated that the naphthalene TLCPs had less chain mobility and stronger molecular interactions, and resulted in a linear rigid chain conformation, endowing the copolyesters with superior properties. As compared with the control copolyester M without naphthalene units, the resulted copolyesters had higher glass transition and melting temperature, higher melt tension, better thermal stability and fiber mechanical property. Overall, the rigidity, molecular interaction and properties of the obtained copolyesters could be efficiently improved after incorporation of the naphthalene units, which is beneficial for its processing and application.
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
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Tao Jin,Haoxuan Shen,Su Ma,Zhouyu Yao,Fang Feng,Yingyuan Hu,Ming Gao,Xuedong Wang
Nonylphenol (NP) is a common pollutant with high biotoxicity in industrial waste waters, such as printing and dyeing, cleaning, preparation of surfactant and detergents, etc., and can disrupt the endocrine and reproductive system. Therefore, its emission is imperative to be monitored. To achieve the specific detection of NP, we herein synthesized a novel fluorescent ionic liquid (NAIm) bearing a double naphthalene ring. The fluorescent intensity of NAIm was significantly quenched upon the addition of NP, and the underlying quenching mechanism belonged to a static quenching mode. DFT theoretical calculations suggested that the band gap increased by 0.11 eV, where the ground state electrons were transferred from the HOMO orbitals of NP to the LUMO ones of NAIm. The specific detection of NP by NAIm was demonstrated to be feasible. NAIm was also able to identify and quantify NP in ambient samples, and the fortified recoveries for NP was in the range 89–110 %. The newly developed fluorescent ionic liquid holds great promise in specific detection of NP in environmental waters.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 22
·8014
·
IF 3.748
Jiang-Rong Luo,Yi-Dong Liu,Heng Liu,Wei-Peng Chen,Ting-Ting Cui,Liangang Xiao,Yonggang Min
In this paper, a new aromatic diamine monomer 4,4′-(2,6-naphthalenediyl)bis[benzenamine]) (NADA) was synthesized and a series of modified PI films containing naphthalene ring structure obtained by controlling the molar ratio of NADA monomer, ternary polymerization with 4,4′-oxydianiline (ODA), and pyromellitic dianhydride (PMDA). The effects of the introduction of the naphthalene ring on the free volume and various properties of PI were investigated by molecular dynamic simulations. The results show that the comprehensive properties of the modified films are all improved to some extent, with 5% thermal weight loss temperature (Td5%) of 569 °C, glass transition temperature (Tg) of 381 °C, tensile strength of 96.41 MPa, and modulus of elasticity of 2.45 GPa. Dielectric property test results show that the dielectric constant (Dk) of the film at 1 MHz is reduced from 3.21 to 2.82 and dielectric loss (Df) reduced from 0.0091 to 0.0065. It is noteworthy that the PI-1 dielectric constant is reduced from 3.26 to 3.01 at 10 GHz with only 5% NADA doping, which is expected to yield the best ratio and provide the possibility of industrial production.Keywords:naphthalene-containing cyclic diamine;terpolymer;polyimide film;dielectric properties
研究领域:
材料科学
·
高分子化学
·
电气工程
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2023
·
IF 5
Xinhua Wang,Xinyao Ni,You Yuan,Jun Qian,Peiyuan Zuo,Xiaoyun Liu,Qixin Zhuang
All-organic polymer dielectrics used in electrical and electronic systems have been proven to be an efficient option for large-scale industrial production. Modifying the side chain of polymers can improve the energy storage performance of polymers, but it can hardly solve the problem of failure under high-temperature application. Herein, an innovative approach is proposed to introduce a group with high temperature resistance into the main chain to reconstruct the chain structure to solve the abovementioned problem. Concretely, a naphthalene ring was introduced to the chain of polyphenylene benzodioxazole (PBO) that is the most promising polymer applied in a high-temperature environment. The naphthalene ring endows the molecular structure with both enhanced permittivity and breakdown strength by decoupling the conjugation of the main chain, increasing the dielectric constant. Meanwhile, an appropriate ratio of benzene–naphthalene as deep traps enables reduced carriers’ mobility and an increased band gap, thereby enhancing the breakdown strength. The discharged energy density of the copolymer reached 5.26 J/cm3 with a charge–discharge efficiency of 91.8% under 450 MV/m at room temperature. Simultaneously, a discharged energy density of 3.1 J/cm3 was also obtained at 150 °C. This work provides a scalable approach to explore polymer dielectrics by freely introducing a small amount of local structural modifications.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2019
·
IF 3.517
Mingjin Fan,Jia Ai,Chenghong Hu,Xin Du,Feng Zhou,Weimin Liu
In this paper, we present the synthesis and tribological properties of two naphthatate-based lubricating oils. The structure and purity of the oils were analyzed using nuclear magnetic resonance spectra and high resolution mass spectra. Their thermal and oxidation stability, flash point and pour point, viscosity and viscosity index, and friction reduction and anti-wear properties were also tested. In the results, the two isooctyl naphthatate-based oils (INA) displayed better lubricating properties than a reference sample of isooctyl sebacate (ISE) on three different friction pairs . The new oils also offered higher oxidation stability than the reference sample. It was found that the stability and lubrication properties of ester-based lubricating oils can be significantly improved by introducing a naphthalene ring into the molecular structure. This is because there is a large π-electron conjugate system on the naphthalene ring, which not only reduces the likelihood of an oxidation chain reaction, but also enables the oil to form an orderly and stable lubricating film on metal surfaces. One of the oils, 2,3-INA, was found have better oxidation stability than the other one, 1,4-INA, because its oxidized groups are positively affected by the steric and conjugation effects of the two ester groups.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2019
·
IF 1.584
Haoran Zhou,Xupeng Fan,Changwei Liu,Chunyan Qu,Zhen Yuan,Jiaqi Jing,Yao Tang,Daoxiang Zhao,Wanbao Xiao,Kai Su
The choice of basic epoxy resin (ER) is especially important for the design of epoxy adhesive formulations. In the present study, performance of several high-temperature ER systems, prepared using 4,4-diaminodiphenylsulfone as the curing agent by the same curing process, was investigated. The curing behavior was studied by dynamic rheometry and differential scanning calorimetry. The thermal properties of the cured resins were investigated by dynamic thermomechanical analysis, thermomechanical analysis, and thermogravimetric analysis. The peeling properties, mechanical behaviors, and moisture absorptivities of the cured resins were also studied. The results showed traditional diglycidyl ether of bisphenol A epoxy to be insufficient in heat resistance. Naphthalene-based ER and bifunctional cardo ER showed higher glass transition temperature values. However, the processability and adhesive properties may not comply with the application requirements. Biphenyl novolac ER has excellent performance in all aspects, which is suitable for use as a high-temperature adhesive.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）