HIGH PERFORMANCE POLYMERS
·
2020
·
IF 1.568
Xing-Hua Guan,He-Ran Nie,Hong-Hua Wang,Ji-Yong Zhao,Zhi-Peng Wang,Rui Wang,Bao-Feng Liu,Guang-Yuan Zhou,Qiang Gu
A series of aromatic polyesters bearing fluorene and phthalein groups were synthesized from commercially available 9,9-bis(4-hydroxyphenyl)fluorene (BPF), phenolphthalein, and terephthaloyl chloride through an interfacial polymerization method. The microstructure, molecular weight, morphology, thermal properties, and thermal decomposition mechanism of these aromatic polyesters were investigated. Their mechanical properties were also evaluated. The results suggested that the copolymer compositions were approximately equal to the feed compositions. Moreover, the increase in the BPF unit content increased the glass transition and weight loss temperatures of the aromatic polyesters, owing to the strong rigidity of the bulky fluorene group. All the polymers were amorphous and exhibited good solubility in common organic solvents. Hence, the synthesized polymers could be easily cast into flexible films. The copolymer film samples exhibited better mechanical properties than those of the homopolymers. The tensile strength, Young’s modulus, and elongation at break of the polymers first increased gradually, and then decreased with increasing BPF content. Notably, the copolymers exhibited the best mechanical properties at the BPF content range 30–50%. Owing to their characteristics, these synthesized polymers show great potential for application as high performance membrane materials.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
POLYMER INTERNATIONAL
·
2020
·Vol. 70
·期 3
·282-287
·
IF 2.574
Jiaxin Wei,Yingshuang Shang,Da Xu,Zhaoyang Wang,Zilong Jiang,Yanwei Gao,Haibo Zhang
A series of novel poly(ether ketone) copolymers with different contents of fluorene groups were synthesized. The effects of fluorene group content on the thermal and mechanical properties of poly(ether ketone) copolymers were investigated. The introduction of a low content of fluorene groups can lead to an increase in glass transition temperature, thermal stability and heat deflection temperature. Among them, the heat deflection temperature of 10% fluorene-containing poly(ether ketone) copolymers (PEK-FD10) increases from 178 °C (pure poly(ether ketone)) to 196 °C, which means that the material has a higher heat resistance rating. Compared with poly(ether ketone)s, these copolymers have excellent mechanical properties. When the content of fluorene groups is only 2% (PEK-FD2), the strength is significantly improved. And the flexural strength of PEK-FD2 is 149.3 MPa, which is 12% higher than that of poly(ether ketone). It is worth noting that the fracture toughness and impact toughness are also increased significantly. The strain at break of PEK-FD2 is up to 88% and the impact toughness of PEK-FD2 is 54.6 J m −1 . This suggests that the introduction of minute contents of fluorene groups can simultaneously increase the strength and toughness. © 2020 Society of Industrial Chemistry
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 18
·3053
·
IF 4.329
Wenchao Zhang,Kuo Zhao,Feng Guan,Jinghua Yin,Yu Feng,Jialong Li,Yanpeng Li
As a new type of dielectric material, the low dielectric constant and corona resistance life of fluorene polyester (FPE) restricts the range of its applications. In order to simultaneously achieve a high dielectric constant and the long corona aging lifetime of FPE, SiO2nanoparticles were chosen as additive to prepare FPE-based composite films. The microstructure of the composite film was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (IR) and small-angle X-ray scattering (SAXS). The dielectric performances of the composites, including the dielectric constant, breakdown strength and corona resistance lifetime, were investigated. The results show that the introduced SiO2does not destroy the structure of the FPE molecular chain and that it increases the thickness of the filler-matrix interface. The dielectric constant of SiO2/FPE composites increased from 3.54 to 7.30 at 1 Hz. Importantly, the corona resistance lifetime increased by about 12 times compared with the pure FPE matrix. In brief, this work shows what possibilities there might be when considering the potential applications of high-strength insulating materials.Keywords:dielectric;fluorene polyester;composite film;corona aging lifetime
研究领域:
材料科学
·
电气工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2021
·Vol. 59
·期 4
·329-339
·
IF 0
Mengjie Hu,Haiquan Chen,Mengxia Wang,Gang Liu,Chunhai Chen,Guangtao Qian,Youhai Yu
Polyimides (PI's) with low-dielectric constant and excellent organic solubility have broad application prospects in the electronic field. Herein, this study designed a series of novel, low dielectric, organic soluble PI films by creatively introducing fluorene and pyridine ring into diamine monomers. Because of the noncoplanar structure of fluorenyl and the polarization of pyridine ring, PI films achieved a low-dielectric constant (2.22–3.09 at 10 MHz) and excellent organic solubility. Even in some organic solvents with low-boiling points, these PI films still exhibited outstanding solubility. In addition, all the films possessed high-tensile strength (≈120 MPa) and excellent optical transparency (>70%, 450 nm). It was worth noting that the glass transition temperature of films was all above 280°C and 5% weight loss temperature ( T 5% ) was at 486–553°C. In general, the novel high-performance low-dielectric PI films are expected to be used in the field of microelectronics. Graphical A series of novel, low dielectric, organic soluble PI films are synthesized by creatively introducing fluorene and pyridine ring into diamine monomers. Compared with traditional Kapton film, these new polyimides containing fluorenyl and pyridine heterocycles in the main chain have low-dielectric constants.
研究领域:
材料科学
·
电子工程
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DOI
CHINESE JOURNAL OF POLYMER SCIENCE
·
2018
·Vol. 36
·期 8
·970-978
·
IF 2.016
Meng Xiang-Li,Yu Gen-Hua,Ma Jian
Novel poly(aryl ether sulfone ketone)s (PAESK) were synthesized from bisphenol A (BPA), 9,9′-bis(4-hydroxyphenyl) fluorene (BHPF), 4,4′-dichlorodiphenylsulfone (DCS) and 4,4′-difluorobenzophenone (DFB) via nucleophilic substitution polymerization, which were subsequently used to fabricate ultrafiltration membrane by phase-inversion method for high temperature condensed water treatment. The obtained high molecular weight co-polymers with fluorene group with good solubility and good thermal stability, can be easily cast into flexible, white and non-transparent flat films. The influence of molar ratio of BPA and BHPF on the properties of the prepared co-polymers and membranes was investigated in detail. SEM study of the morphology of the membranes indicated that the prepared membranes possessed homogeneous pores on the top surface and were sponge-like or finger-like in cross-section. Pure water flux of the membranes increased from 71.87 L·m −2 ·h −1 to 247.65 L·m −2 ·h −1 , while the retention of BSA decreased slightly, and the water contact angle decreased from 82.1° to 55.6° with the PVP concentration from 0 wt% to 10 wt%. With increasing concentration of PVP, the mechanical properties of membranes decreased, while the thermal stability increased. The permeate flux measurement showed that the PAESK membrane had the potential for high temperature condensed water treatment.
研究领域:
材料科学
·
环境工程
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产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2012
·Vol. 52
·期 11
·2473-2481
·
IF 1.302
Zien Fu,Huan Liu,Hualun Cai,Xin Liu,Guo Ying,Kai Xu,Mingcai Chen
Three difunctional fluorene-based benzoxazine compounds were synthesized via Mannich condensation and were characterized by proton nuclear magnetic resonance spectroscopy ( 1 H NMR), Fourier transform infrared spectroscopy (FTIR), and elementary analysis (EA). The polymerization of benzoxazine monomers were investigated with differential scanning calorimeter (DSC) method. Thermal properties of the polybenzoxazines were studied by thermogravimetric analysis (TGA) and DSC. Water absorption of the polybenzoxazines was tested. Contact angle measurement was employed to characterize the surface property of materials. The glass transition temperatures ( T g s) and thermal stability were improved significantly in comparison with bisphenol-A-based analogue because of the incorporation of rigid fluorenyl group. The fluorenyl-based polybenzoxazines showed hydrophobic characteristics, which was ascribed to the low polarity of fluorenyl and pi–pi stacking interaction of fluorenyl on the surface. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 23
·10497-10506
·
IF 2.7
Zhoufeng Wang,Yingying Liu,Bolin Wang,Xiubo Long,Wenlong Yao
Random and block polyarylates were synthesized using bisphenol A (BPA), bisphenol fluorene (BHPF), terephthaloyl chloride (TPC), and isophthaloyl chloride (IPC) as raw materials. The synthesis strategies of one-step and stepwise interfacial polymerization methods were adopted. Both types of polyarylates exhibited similar solubility, with block polyarylates showing slightly broader solvent selectivity. The presence of large sterically hindered fluorene groups in BHPF monomers rendered both block and random polyarylates amorphous by restricting the movement of macromolecular segments. The polyarylates demonstrated excellent thermal stability (T5% = around 490 °C) and a high glass transition temperature (Tg > 210 °C). As the covalent bonds of the monomer linkage showed no significant difference, the thermal stability of both types of products was similar. The glass transition temperature increased with an increase in TPC and diefluorene monomer content. The tensile strengths of the random and block polyarylate films ranged from 45.77–69.89 MPa and 49.49–55.29 MPa, respectively, indicating the high tensile strength of the resulting polyarylates. While the block polyarylates did not show significant differences from the conventional properties of random polyarylates, the synthesis of block polyarylates in this study represents a novel attempt, further highlighting the significant influence of the large pendant group of the main chain on the ordered arrangement of molecular segments.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Wenchao Zhang,Meilin Gao,Dongyu Hou,Bowen Hou,Shiyu Liu,Qingguo Chen,Jinghua Yin,Dong Yue,Yu Feng
Polymer is the dielectric material of choice for dielectric capacitors. However, the low dielectric constant limits the polymer from achieving a satisfactory energy density. Therefore, researchers synergistically integrate a variety of components to effectively improve the energy storage performance. In this paper, Polyetherimide (PEI) and Fluorene Polyester (FPE) hybrid composite films are prepared by a linear/linear blending strategy. The dielectric constants of PEI and FPE are 3.38 and 3.45 at 10 Hz, and the dielectric constant is increased to 4.02 when the mass fraction of FPE is 10%. The breakdown field strength of PEI and FPE is 553.51 and 589.34 kV/mm, and the breakdown field strength reaches 746.51 kV/mm after blending. At 800 kV/mm, the energy storage density and energy storage efficiency of the hybrid composite film reach 11.38 J/cm 3 and 86.14%. Compared with PEI, the performance of the prepared blended composite film has been comprehensively improved, which provides a corresponding theoretical analysis and experimental strategy for the preparation of high-performance all-organic blended composite dielectric and also has potential application prospects in energy storage devices.
研究领域:
材料科学
·
能源存储
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2014
·
IF 4.908
Guang Lu Han,Pei Yu Xu,Ke Zhou,Qiu Gen Zhang,Ai Mei Zhu,Qing Lin Liu
A series of poly (arylene ether sulfone) block copolymers with hydrophilic segments containing fluorene groups were successfully synthesized as confirmed by 1 H NMR. The molecular weights were measured in the range 115–140 kDa by gel permeation chromatography (GPC). The hydrophilic segment showed a helical structure due to fluorene with butterfly-shaped framework in the main chain. With incorporating imidazolium groups, the microphase separation can also be achieved between the hydrophilic and the hydrophobic moieties. The membrane structure was characterized by positron annihilation lifetime spectroscopy (PALS) and small angle X-ray scattering (SAXS). The block copolymers were used to prepare membranes successfully for pervaporation separation of methanol (MeOH)/methyl tert-butyl ether (MTBE) mixture. The correlation between the membrane microstructure and the separation performance was discussed thoroughly. By increasing the hydrophilic segment proportion, the permeation flux increased while the separation factor declined. The membranes have the highest permeation flux (0.334 kg m −2 h −1 ) and the lowest separation factor (287) for a 15 wt% MeOH feed mixture at 40 °C, and the mass fraction of MeOH in the permeate is higher than 98 wt%.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 38
·19869-19877
·
IF 3.708
Jin-Jin Li,Jian-Jian Wang,Yin-Ning Zhou,Zheng-Hong Luo
The origin of the low-energy emission of fluorene-based rod-coil block copolymers still remains controversial. In this work, a series of polyfluorene-based rod-coil block copolymers having different coil segments, i.e., poly[2,7-(9,9-dihexylfluorene)]-block-poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate, (PF-b-PHFBMA), PF-b-poly(butylmethacrylate) (PF-b-PBMA), PF-b-poly(2-hydroxyethyl methacrylate) (PF-b-PHEMA) and PF-b-poly(acrylic acid) (PF-b-PAA), were synthesized using the ATRP technique. The optical and surface properties and thermal behaviors of these copolymers were systematically investigated. In particular, different thermal treatment conditions, including annealing temperature, annealing time and annealing atmosphere were introduced to study the effect of coil segment on the copolymer spectral stability. The incorporation of PBMA, PHEMA and PAA segments to PF could indeed improve the copolymer spectral stability, while the PHFBMA block brought undesirable low-energy emission. In addition, water contact angle (WCA) measurements of the copolymer films before and after annealing further demonstrated that the low-energy emission of PF-based rod-coil block copolymers was attributed to the molecular aggregation rather than the formation of fluorenone defects.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2017
·
IF 1.179
Tengyang Zhu,Xing Yang,Xiaoqi He,Yayun Zheng,Jujie Luo
A series of new aromatic polyamides (PAs) and copolyamides (CPAs) containing fluorene group have been synthesized through polycondensation reaction. The chemical structure was confirmed by Fourier transform infrared and proton nuclear magnetic resonance (1H NMR). PAs and CPAs exhibited the higher thermal stability (Td15 > 378°C in nitrogen), the higher glass transition temperature (Tg > 345°C), and excellent solubility in polar solvent. Gas transport properties of the PA and CPA membranes were investigated using different single gases (hydrogen (H2), carbon dioxide (CO2), oxygen (O2), methane (CH4), and nitrogen (N2)). We discussed the effect of chemical structure and operating temperature on gas transport properties. The results show that PA-1 containing a hexafluoroisopropylidene moiety exhibited the highest gas permeability (PH2 = 12.71 Barrer, PCO2 = 12.26 Barrer, and PO2 = 2.62 Barrer) and reasonably good selectivity (α(H2/N2) = 27.63, α(CO2/N2) = 26.65, and α(O2/N2) = 5.70) at 25°C and 1 atm. For all the membranes, gas permeability gradually increased with the increase in operating temperature, while the selectivity gradually decreased. These gas permeation results were well correlated with fractional free volume, interchain d-spacing (dsp), and intermolecular interaction.
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
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Shuo Wang,Pei Wang,Yunlong Sun,Jiyong Zhao,Zhipeng Wang
The rapid advancement of high-frequency communication networks has imposed more rigorous demands on the overall characteristics of dielectric materials. Poly(aryl ether ketone)s (PAEKs) are good candidate materials for applications in microelectronic devices due to their excellent thermal stability, mechanical properties, and chemical stability. In this work, we endeavored to incorporate large-volume fluorene structures into fluoro-PAEKs, employing strategies to enhance the polymer free volume and reduce polarizations in order to decrease the values of Dk and Df at high frequency. Therefore, a series of poly(ether ketone) (PEK-pOCFBPF-X) copolymers were designed and synthesized through nucleophilic polymerization using 4,4-difluorobenzophenone (DFK), phenolphthalein anilide-containing trifluoromethoxy groups (PPPBP-pOCF3), and a structurally ordered bisphenol fluorene (BPF) as the monomers. The results demonstrate that the introduction of BPF into fluoro-PAEKs resin leads to a low dielectric constant (2.713–2.782@10 GHz) and dielectric loss (0.00597–0.00825@10 GHz), as well as exceptional thermal properties (Tg = 232–240 °C, Td5% = 518–536 °C). Moreover, the copolymer exhibits high mechanical strength (tensile strength ≥ 81 MPa), minimal water absorption (≤0.0063), and excellent solubility. The incorporation of trifluoromethoxy and fluorenyl groups into copolymers significantly enhances the free volume fraction (5.5%–5.8%), resulting in a lower density and reduction in the dielectric constant. Simultaneously, by introducing C–F bonds with lower polarizability, the overall polarizability of the polymer is effectively diminished. These fluoro-PAEKs films, which exhibit superior thermal stability and a low dielectric constant, have great potential for applications in the high-performance flexible electronic packaging field and communication usage.
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
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