共查询到20条相似文献,搜索用时 296 毫秒
1.
Debabrata Bhadra Md. G. Masud S. Sarkar J. Sannigrahi S. K. De B. K. Chaudhuri 《Journal of Polymer Science.Polymer Physics》2012,50(8):572-579
A novel two‐phase polymer nanocomposite film comprising of polyvinylidene fluoride (PVDF) and nanocrystalline (~90 nm) semiconducting multiferroic BiFeO3 (BFO) have been fabricated by hot‐molding technique. Such flexible thick nanocomposite films, semicrystalline in nature, exhibited extraordinarily high effective dielectric permittivity εeff ~ 103 (compared with that of pure PVDF) near the low percolation threshold (fc = 0.12) at room temperature (RT) and the films also possessed low dielectric loss (~0.18). The polarization‐electric field (P‐E) hysteresis loops are displayed at RT, which indicate ferroelectric like behavior of PVDF still persists in the percolative nanocomposite. There is also large increase of remanent polarization of BFO in the composite indicating improvement of the multiferroic behavior of BFO embedded in the PVDF polymer. The sample also indicates good fatigue endurance. Formation of microcapacitors and percolative behavior are correlated to explain the obtained results based on the special geometry of the BFO nanofillers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
2.
The effect of Lucentite™ STN nanoclay on the relaxation behavior of poly(vinylidene fluoride) (PVDF) nanocomposites was investigated using dielectric relaxation spectroscopy (DRS) and wide- and small-angle X-ray scattering. Lucentite™ STN is a synthetic nanoclay based on hectorite structure containing an organic modifier between the hectorite layers. The addition of this nanoclay to PVDF results in preferential formation of the beta-crystallographic phase. When the STN content increased to 5% and 10%, only the beta-phase was observed. Bragg long period and lamellar thickness both decrease with STN addition. The relaxation rates for processes termed αa (glass transition, related to polymer chain motions in the amorphous regions) and αc (related to polymer chain motions in the crystalline regions and fold surfaces) can be described either with the Vogel-Fulcher-Tamman equation or with Arrhenius behavior, respectively. DRS shows that the αa relaxation rate increases with the concentration of STN because of the reduction of intermolecular correlations between the polymer chains, caused by the presence of layered silicate nanoclay particles, which serve to segregate polymer chains in the amorphous regions. Comparing samples with beta-crystal phase dominant, the relaxation rate for the αc relaxation also increases with concentration of STN in all nanocomposite samples. Dielectric properties at low frequencies are dominated by the dc conductivity, and as more STN is added, the conductivity increases rapidly. The addition of 10% STN makes the dc conductivity increase by almost four decades when compared with neat PVDF. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2520–2532, 2009 相似文献
3.
Juan Antonio Asensio Salvador Borrs Pedro Gmez‐Romero 《Journal of polymer science. Part A, Polymer chemistry》2002,40(21):3703-3710
A sulfonated derivative of polybenzimidazole is reported, and its properties are analyzed in comparison with related polybenzimidazole proton‐conducting materials. Poly(2,5‐benzimidazole), poly(m‐phenylenebenzobisimidazole), and poly[m‐(5‐sulfo)‐phenylenebenzobisimidazole] were prepared by condensation of the corresponding monomers in polyphosphoric acid. Several adducts of these polymers with phosphoric acid were prepared. The resulting materials were characterized by chemical analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis; also, the dc conductivity of doped and undoped derivatives was measured. Similar to what has been observed for the commercial polybenzimidazole polymer (also examined here for comparison), the title polymers exhibit high thermal stability. Furthermore, their doping with phosphoric acid leads to a significant increase in conductivity from less than 10?11 Scm?1 for the undoped polymers to 10?4 Scm?1 (both at room temperature) for their acid‐loaded derivatives. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3703–3710, 2002 相似文献
4.
Jialong Li Jinghua Yin Chen Yang Na Li Yu Feng Yuanyuan Liu He Zhao Yanpeng Li Congcong Zhu Dong Yue Bo Su Xiaoxu Liu 《Journal of Polymer Science.Polymer Physics》2019,57(10):574-583
In order to enhance dielectric properties and energy storage density of poly(vinylidene fluoride‐hexafluoro propylene) (PVDF‐HFP), surface charged gas‐phase Al2O3 nanoparticles (GP‐Al2O3, with positive surface charges, ε’ ≈ 10) are selected as fillers to fabricate PVDF‐HFP‐based composites via simple physical blending and hot‐molding techniques. The results show that GP‐Al2O3 are dispersed homogeneously in the PVDF‐HFP matrix and the existence of nanoscale interface layer (matrix‐filler) is investigated by SAXS. The dielectric constant of the composites filled with 10 wt % GP‐Al2O3 is 100.5 at 1 Hz, which is 5.6 times higher than that of pure PVDF‐HFP. The maximum energy storage density of the composite is 4.06 J cm?3 at an electrical field of 900 kV mm?1 with GP‐Al2O3 content of 1 wt %. Experimental results show that GP‐Al2O3 could induce uniform fillers’ distribution and increase the concentration of electroactive β‐phase as well as enhance interfacial polarization in the matrix, which resulted in enhancements of dielectric constant and energy storage density of the PVDF‐HFP composites. This work demonstrates that surface charged inorganic‐oxide nanoparticles exhibit promising potential in fabricating ferroelectric polymer composites with relatively high dielectric constant and energy storage. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 574–583 相似文献
5.
Enhanced dielectric properties of polymer composite films induced by encapsulated MWCNTs with a one core‐two shell structure
下载免费PDF全文
![点击此处可从《Journal of Polymer Science.Polymer Physics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Multiwalled carbon nanotubes (MWCNTs) can endow high dielectric constant to polymer‐based composites. However, the accompanying poor dispersion of MWCNTs and high dielectric loss for composites severely limit their application in dielectric field. Herein, a modified acid‐treated MWCNTs encapsulated by the polyaniline/poly(sodium 4‐styrenesulfonate) layers (aMWCNTs@PANI‐PSS) with a one core‐two shell structure was fabricated by in situ polymerization followed by electrostatic self‐assembly technique. Furthermore, the composite films based on aMWCNTs@PANI‐PSS/poly(vinylidenefluoride‐hexaflouropropylene) (PVDF‐HFP) were fabricated by a solution‐casting method. An ultrathin insulating PSS shell is wrapped onto aMWCNTs@PANI, resulting in the improvement of dispersibility for aMWCNTs@PANI and the decrease of dielectric loss for composite films. When the content of aMWCNTs@PANI‐PSS is 5.0 wt %, the dielectric constant of aMWCNTs@PANI‐PSS/PVDF‐HFP reaches 430 (100 Hz), which is about 55 times of pure PVDF‐HFP and 1.7 times of aMWCNTs@PANI/PVDF‐HFP (247). Besides, the responding dielectric loss of aMWCNTs@PANI‐PSS/PVDF‐HFP composite film is only 0.67, much lower than that of aMWCNTs@PANI/PVDF‐HFP (25) and aMWCNTs/PVDF‐HFP (3185). © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 948–956 相似文献
6.
Masayuki Nagai Koh Nakamura Hiroki Uehara Tetsuo Kanamoto Yoshiyuki Takahashi Takeo Furukawa 《Journal of Polymer Science.Polymer Physics》1999,37(18):2549-2556
Oriented poly(vinylidene fluoride) (PVDF) films with β‐form crystals have been commonly prepared by cold drawing of a melt‐quenched film consisting of α‐form crystals. In this study, we have successfully produced highly oriented PVDF thin films (20 µm thick) with β‐crystals and a high crystallinity (55–76%), by solid‐state coextrusion of a gel film to eight times the original length at an established optimum extrusion temperature of 160°C, some 10°C below the melting temperature. The resultant drawn films had a highly oriented (orientation function fc = 0.993) fibrous structure, showing high mechanical properties of an extensional elastic modulus of 8.3 GPa and tensile strength of 0.84 GPa, along the draw direction. Such highly oriented and crystalline films exhibited excellent ferroelectric and piezoelectric properties. The square hysteresis loop was significantly sharper than that of a conventional sample. The sharp switching transient yielded the remnant polarization Pr of 90 mC/m2, and the electromechanical coupling factor kt was 0.24 at room temperature. These values are about 1.5 times greater than those of a conventional β‐PVDF film. Thus, solid‐state coextrusion near the melting point was found to be a useful technique for the preparation of highly oriented and highly crystalline β‐PVDF films with superior mechanical and electrical properties. The morphology of the extrudate relevant to such properties is discussed. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2549–2556, 1999 相似文献
7.
Poly(vinylidene fluoride)/silica (PVDF/SiO2) hybrid composite films were prepared via sol–gel reactions from mixtures of PVDF and tetraethoxysilane in dimethylacetamide. Their morphology, crystalline structure, and thermal, mechanical, and electrical properties were examined. For morphology measurements, scanning electron microscopy and optical microscopy were applied. X‐ray diffraction and infrared analyses showed that the crystalline structure of PVDF was not changed much by the addition of SiO2, indicating that there was no interaction between PVDF and SiO2. With increasing SiO2 content, the melting temperature rarely changed, the degree of crystallinity and the dielectric constant decreased, and the decomposition temperature slightly increased. A PVDF/SiO2 hybrid composite film with 5 wt % SiO2 exhibited balanced mechanical properties without a severe change in the crystalline structure of PVDF, whereas for the hybrid composites with higher SiO2 contents (>10 wt %), the mechanical properties were reduced, and the spherulite texture of PVDF was significantly disrupted by the presence of SiO2 particles. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 19–30, 2002 相似文献
8.
采用流延热压工艺制备Ba0.6Sr0.4TiO3(BST)/聚偏氟乙烯(PVDF)?聚甲基丙烯酸甲酯(PMMA)复合薄膜,研究了PMMA含量对复合材料微观组织结构和介电性能的影响规律。结果表明,BST相能够均匀分散在聚合物基体中,归因于PMMA与PVDF良好的相容性,2种聚合物之间的界面不分明;随着PMMA含量的增加,复合材料的介电常数先降低后升高,耐击穿强度和介电可调性先增加后减少。PMMA含量(体积分数)为15%的BST/PVDF?PMMA15复合材料的综合性能最佳:介电常数为23.2,介电损耗为0.07,耐击穿强度为1412 kV·cm-1,在550 kV·cm-1偏压场下,介电可调性为26.2%。 相似文献
9.
Poly(vinylidene fluoride)(PVDF)/Na+‐MMT composites have been successfully prepared utilizing sodium montmorillonite (Na+‐MMT) via N,N‐dimethylformamide (DMF) solution mixing. The dispersion of Na+‐MMT layers in composites were investigated by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The effect of adding Na+‐MMT on crystallization behavior of PVDF was specifically studied. The β‐crystalline nucleation effect of Na+‐MMT was investigated and confirmed by differential scanning calorimetry (DSC), XRD, and Fourier transform infrared (FTIR) results. The interaction between PVDF and the surface of Na+‐MMT layers in DMF solution was confirmed by UV‐Vis absorbency. The effect of adding Na+‐MMT on rheological and electrical properties of PVDF/Na+‐MMT composites were also determined. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 903–911, 2009 相似文献
10.
11.
A. Linares A. Nogales D. R. Rueda T. A. Ezquerra 《Journal of Polymer Science.Polymer Physics》2007,45(13):1653-1661
The relaxation behavior of a series of compatible poly(vinylidene fluoride) (PVDF) and poly(vinyl acetate) (PVA) blends has been investigated by dielectric spectroscopy in a broad frequency and temperature range. Blends with PVDF content higher than 60% in weight are semicrystalline. Semicrystalline blends show a relaxation (αc) occurring in the crystalline phase of PVDF. Both semicrystalline and amorphous blends exhibit two processes, α and β associated to the overall segmental dynamics and to localized motions in the amorphous phase, respectively. For high PVDF content samples, the β relaxation exhibits an anomalous behavior characterized by a crossover from segmental to local dynamics, upon decreasing temperature, attributed to confinement effects taking place in PVDF segregated regions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1653–1661, 2007 相似文献
12.
Two types of the epoxy-POSS nanocomposites were prepared and their electrical/dielectric and thermomechanical properties were determined. The mono- and octa-epoxyfunctionalized POSS (POSS,E1 and POSS,E8) were covalently incorporated in the epoxy network matrix DGEBA-3,3′-dimethyl-4,4′-diaminocyclohexylmethane (Laromin C260) as pendant units or as polyhedral junctions, respectively. While the POSS junctions are well dispersed in the hybrid network DGEBA-Laromin-POSS,E8, the pendant POSS aggregate to form large crystalline POSS domains.The properties of the nanocomposites correlate with the morphology. The nanocomposites with inhomogeneously dispersed large aggregates of pendant POSS,E1 show poor properties, including low Tg and thermal stability, and the high dielectric loss factor at higher temperatures. On the contrary, the well homogeneous nanocomposites containing POSS,E8 dispersed units display improved electrical properties in the range of 1–10 wt.% POSS. The hybrid exhibits the high resistivity (1 × 1015 Ω m) and polarization index pi1 characterizing electrical relaxation, as well as the low dielectric loss factor tan δ, mainly at temperatures above 50 °C. Moreover, the material shows improved thermo oxidative stability and enhanced thermomechanical behavior. Consequently, this nanocomposite was proved to be a prospective insulation material particularly for a high temperature electrotechnical application. In contrast to electrical properties being the best at a low POSS content, the thermomechanical properties, such as rubbery modulus and Tg, are gradually improving with increasing POSS content due to growing crosslinking density. 相似文献
13.
Meltem Yanilmaz Chen Chen Xiangwu Zhang 《Journal of Polymer Science.Polymer Physics》2013,51(23):1719-1726
SiO2/polyvinylidene fluoride (PVDF) composite nanofiber‐coated polypropylene (PP) nonwoven membranes were prepared by electrospinning of SiO2/PVDF dispersions onto both sides of PP nonwovens. The goal of this study was to combine the good mechanical strength of PP nonwoven with the excellent electrochemical properties of SiO2/PVDF composite nanofibers to obtain a new high‐performance separator. It was found that the addition of SiO2 nanoparticles played an important role in improving the overall performance of these nanofiber‐coated nonwoven membranes. Among the membranes with various SiO2 contents, 15% SiO2/PVDF composite nanofiber‐coated PP nonwoven membranes provided the highest ionic conductivity of 2.6 × 10?3 S cm?1 after being immersed in a liquid electrolyte, 1 mol L?1 lithium hexafluorophosphate in ethylene carbonate, dimethyl carbonate and diethyl carbonate. Compared with pure PVDF nanofiber‐coated PP nonwoven membranes, SiO2/PVDF composite fiber‐coated PP nonwoven membranes had greater liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO2/PVDF composite fiber‐coated PP nonwoven membrane separators were assembled into lithium/lithium iron phosphate cells and demonstrated high cell capacities and good cycling performance at room temperature. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1719–1726 相似文献
14.
Fully printed flexible audio system on the basis of low‐voltage polymeric organic field effect transistors with three layer dielectric
下载免费PDF全文
![点击此处可从《Journal of Polymer Science.Polymer Physics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Georg C. Schmidt Daniel Höft Katherina Haase Maxi Bellmann Bahman Kheradmand‐Boroujeni Tomi Hassinen Henrik Sandberg Frank Ellinger Arved C. Hübler 《Journal of Polymer Science.Polymer Physics》2015,53(20):1409-1415
Fully mass printed, flexible and truly polymeric organic field effect transistors consisting of a three layer dielectric made of CYTOP (low‐k), PVA (intermediate) and P(VDF‐TrFE‐CTFE)(high‐k) are introduced. Gravure‐, flexo‐and screen printing were selected as highly productive manufacturing technologies. These OFETs work at strongly reduced voltages and show high field effect mobility (µ = 0.2 cm2/Vs) and remarkable good bias stress stability at very high current density (50 µA/mm). Fully printed OFETs are used for the realization of ring oscillators working in the kHz regime at reduced supply voltage (10 V). In combination with printed fully polymeric piezoelectric loudspeakers, this work shows for the first time fully printed flexible audio systems. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1409–1415 相似文献
15.
Yaw‐Terng Chern Jane‐Jen Wang 《Journal of polymer science. Part A, Polymer chemistry》2009,47(6):1673-1684
This work reports the synthesis and characterization of diamantane‐based polyimides obtained from 4,9‐bis[4(3,4‐dicarboxyphenoxy)phenyl]diamantane dianhydride and various aromatic diamines. Interestingly, the diamantane‐based polyimides were very stable to hydrolysis. This novel polyimide exhibits a low dielectric constant (2.65–2.77), low moisture absorption (<0.67%), good solubility, high Tg and unusually high thermal stability. Dynamic mechanical analysis (DMA) reveals that the diamantane‐based polyimides have high Tg ranging from 281 to 379 °C. The high‐temperature β1 subglass transition around 285 °C was observed in polyimide 6a derived from 2,2′‐bis(trifluoromethyl)benzidine. This class of novel diamantane‐based polyimide is very promising for electronic applications, because of its good mechanical properties, good thermal stability, low dielectric constant, excellent hydrolytic resistance, and low moisture absorption. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1673–1684, 2009 相似文献
16.
《Journal of Polymer Science.Polymer Physics》2018,56(10):795-802
Ferro‐ and piezo‐electric poly(vinylidene fluoride) (PVDF) thin film is reported to be obtained by using a poly(ionic liquid) (PIL) [poly(2‐(dimethylamino)ethyl methacrylate) methyl chloride quaternary salt] through solution route. The short range interactions between localized cationic ions of PIL and polar >CF2 of PVDF are responsible for modified polar γ‐PVDF (T3GT3Ḡ) formation. Modification in chain conformation of PVDF is confirmed by FTIR, XRD, and DSC studies suggesting the miscible PVDF–PIL (PPIL) blend. Up to 40 wt % loading of PIL in PVDF matrix enhances relative intensity of γ‐phase up to 50% in the entire crystalline phase. The P‐E hysteresis loop of PVDF‐PIL blends at 25 wt % PIL loading (PPIL‐25) thin film at sweep voltage of ±50 V shows excellent ferroelectric property with nearly saturated high remnant polarization ∼6.0 µC cm−2 owing to large proportion of γ‐PVDF. However, non‐polar pure PVDF thin film shows unsaturated hysteresis loop with 1.4 µC cm−2 remnant polarization. The operation voltage decreases effectively because of the polar γ‐phase formation in PPIL blended film. High‐sensitivity piezo‐response force microscopy shows electromechanical switching property at low voltages in PPIL‐25 thin films through local switching measurements, making them potentially suitable as ferroelectric tunnel barriers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 795–802 相似文献
17.
Rui Li Chuanxi Xiong Dongliang Kuang Lijie Dong Youan Lei Junlong Yao Ming Jiang Liubin Li 《Macromolecular rapid communications》2008,29(17):1449-1454
A novel capacitor with high dielectric constant (ε) has been developed by blending poly(vinylidene fluoride) (PVDF) with polyamide (PA11). The blends show high dielectric constants (εblend = 40), which give better frequency stability (1 MHz), and excellent mechanical properties. Based on certain volume fractions, the measured dielectric constants (ε blend ) were found to exceed those of the corresponding polymers, in contrasted to conventional composites, where εpolymerA < εcomposite < εpolymerB. SEM investigations suggest that the enhanced dielectric behavior originates from significant interfacial polymer‐polymer interactions. DSC and XRD demonstrate that blending PA11 with PVDF affects the crystalline behavior of each component. However, the PA11/PVDF blends exhibit a slightly high dielectric loss (tanδ ≈ 0.17), which is a great disadvantage to a capacitor. Adding a copolymer of styrene and maleic anhydride decreased the dielectric loss (tanδ ≈ 0.057) and increased the dielectric constant (εblend = 60). Our findings suggest that the high‐ε polymeric blends created represent a novel type of material that is flexible and easy to process, of relatively high dielectric constant, of high breakdown strength and, moreover, is suited to applications in flexible electronics.
18.
Maria M. Pérez‐Madrigal Diego A. Ochoa Jose E. García Elaine Armelin Carlos Alemán 《Journal of Polymer Science.Polymer Physics》2016,54(18):1896-1905
Dielectric elastomer actuators (DEAs) transform electrical energy into mechanical work. However, despite displaying exceptional features, the low permittivity of elastomers restricts their application. Hence, to overcome this limitation, DEAs are fabricated by dispersing poly(3‐methylthiophene acetate) (P3TMA), a polarizable conducting polymer, into poly[styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] (SEBS), a thermoplastic elastomer with excellent mechanical properties. Although high‐quality SEBS:P3TMA films are obtained for all compositions (between 0.5 and 20 wt % P3TMA), their thickness and surface roughness increase with the nano‐sized filler content. Moreover, the conducting particles are well integrated into the SEBS network with no evidence of aggregation or significant change in the mechanical properties of the composites. P3TMA, which forms encapsulated conductive domains within the polymeric matrix, improves the dielectric behavior of SEBS:P3TMA by increasing their dielectric constant with low dielectric losses and no current leakage. Thus, indicating the potential future application of these nanocomposites as elastomer actuators or high energy density capacitors. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1896–1905 相似文献
19.
Joel M. Carr Matthew Mackey Lionel Flandin Donald Schuele Lei Zhu Eric Baer 《Journal of Polymer Science.Polymer Physics》2013,51(11):882-896
Polymer films with enhanced dielectric and breakdown properties are essential for the production of high energy density polymer film capacitors. By capitalizing on the synergistic effects of forced assembly nanolayer coextrusion and biaxial orientation, polymer multilayer films using poly(ethylene terephthalate) (PET) and a poly(vinylidene fluoride‐co‐tetrafluoroethylene) [P(VDF‐TFE)] copolymer were produced. These films exhibited breakdown fields, under a divergent field using needle/plane electrodes, as high as 1000 kV mm?1. The energy densities of these same materials, under a uniform electric field measured using plane/plane electrodes, were as high as 16 J cm?3. The confined morphologies of both PET and P(VDF‐TFE) were correlated to the observed breakdown properties and damage zones. On‐edge P(VDF‐TFE) crystals induced from solid‐state biaxial stretching enhanced the effective P(VDF‐TFE) layer dielectric constant and therefore increased the dielectric contrast between the PET and P(VDF‐TFE) layers. This resulted in additional charge buildup at the layer interface producing larger tree diameters and branches and ultimately increasing the breakdown and energy storage properties. In addition to energy storage and breakdown properties, the hysteresis behavior of these materials was also evaluated. By varying the morphology of the P(VDF‐TFE) layer, the low‐field dielectric loss (or ion migration behavior) could be manipulated, which in turn also changed the observed hysteresis behavior. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 882–896 相似文献
20.
Crosslinkable high dielectric constant polymer dielectrics for low voltage organic field‐effect transistor memory devices
下载免费PDF全文
![点击此处可从《Journal of polymer science. Part A, Polymer chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chih‐Chien Hung Hung‐Chin Wu Yu‐Cheng Chiu Shih‐Huang Tung Wen‐Chang Chen 《Journal of polymer science. Part A, Polymer chemistry》2016,54(19):3224-3236
I n this study, we successfully synthesized water/methanol soluble random copolymers with a high dielectric constant, poly(n‐(hydroxymethyl) acrylamide‐co‐5‐(9‐(5‐(diethylamino)pentyl)?2‐(4‐vinylphenyl)?9H‐fluorene(P(NMA‐co‐F6NSt)), which contained chemical crosslinkable segment (NMA) and hole trapping building block (F6NSt). The feeding molar ratios of two monomers (NMA:F6NSt) were set as 100:0, 95:5, 80:20, and 67:33 for the copolymers of P1 , P2 , P3, and P4 , respectively. The crosslinked P(NMA‐co‐F6NSt) thin film could serve as both dielectric and charge storage layers in organic field‐effect transistor (OFET) memory device and exhibited high k (i.e., 4.91–6.47) characteristics, leading to a low voltage operation and a small power consumption. Devices based on the P1 ‐ P4 dielectrics showed excellent insulating properties and good charge storage performance under a low operating voltage in a range of ±5V because of tightly network structures and well‐dispersed trapping cites. In particular, P3 ‐based memory device exhibited a large memory window of 4.13 V with stable data retention stability over 104 s, a large on/off ratio of 104, and good endurance characteristics as high as 200 cycles. The above results suggested that a high‐performance OFET memory device could be facilely achieved using the novel crosslinkable high‐k copolymers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3224–3236 相似文献