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首次合成了氟芳胺基磷酸酯和氟磺酰胺基磷酸酯.对氟苯胺、α-氯-4-三氟甲基吡啶胺、α-氯-4-三氟甲基氧化吡啶胺与二乙氧基磷酰氯在乙腈或DMF中反应,得到氟芳胺基磷酸酯.氟烷基磺酰甲胺与二乙氧基磷酰氯反应,以金属钠处理,相应钠盐在乙腈或DMF中,于室温下反应将得到氟烷磺酰胺基磷酸酯. 相似文献
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本文报导了氟烷基溴化物与叔胺在Ni催化剂存在下的反应, 溴化与叔胺在零价Ni配合物存在, 室温下能生成氟烷基烯胺, 并证明溴化物与碘化物是按同一机理进行反应的, 即通过电子转移而引发的一个自由基反应过程。 相似文献
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和RFSO3CH2R(1)及RFSO3CF2RF'(2)不同,RFSO3CF2H(3)(RF=CF3,3a;ICF2CF2OCF2CF2,3b;Cl2CFCF2OCF2CF2,3c;ClCF2CF2OCF2CF2,3d)和亲核试剂的反应较为复杂。除X[-](X=F,Cl,I)及C2H5OH与3反应时只发生C-O键断裂外,其它试剂如RCO2[-],C6H5S[-]等既可进攻硫原子又可进攻碳原子,但以前者为主。碱性较强的试剂如RO[-]还可夺取二氟甲基的氢原子而产生二氟卡宾。在3中由于甲基碳上存在两个氟原子,确实有着一定的屏蔽作用,因此阻碍了某些试剂对它的亲核进攻,但由于这个碳上还连有一个氢原子,所以这种屏蔽作用并不完全。 相似文献
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运用生物电子等排及拼合设计原理,设计并合成了14个新型的噻吩并四氢吡啶芳酸醚类化合物(4a~4j和8a~8d),其结构经1H NMR,13C NMR和ESI-MS表征。采用Bron比浊法测定了4a~8d对腺苷二磷酸(ADP)和花生四烯酸(AA)诱导的血小板聚集抑制活性。结果表明:4-【3-{6,7-二氢噻吩并[3,2-c]吡啶-5(4H)-基}丙氧基】-苯甲酸对AA诱导的血小板聚集和4-【3-{6,7-二氢噻吩并[3,2-c]吡啶-5(4H)-基}丙氧基】-3,5-二甲氧基苯甲酸对ADP诱导的血小板聚集均显示出较强的抑制活性,其IC50分别为0.020 mmol·L-1和0.018 mmol·L-1。 相似文献
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含氟烯醚可作为亲偶极体进行偶极环加成反应. 某些含氟烯醚在亲核试剂作用下可作为烷基化试剂. 本文报导了Wittig反应通过芳氧. 相似文献
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利用双酚A型聚芳醚酮与联硼酸频哪醇酯在[Ir(COD)Cl]2和4,4'-二叔丁基-2,2'-联吡啶催化下反应,制备了新型含硼酸酯双酚A型聚芳醚酮,通过控制联硼酸频哪醇酯的投入量来实现硼酸酯的定量引入.再经过高碘酸钠作用得到含硼酸双酚A型聚芳醚酮,最后,通过高效Suzuki-Miyaura反应将偶氮定量引入到聚芳醚酮主链.利用核磁共振(1H NMR)确定了聚合物的结构,利用凝胶渗透色谱(GPC)确定了聚合物的分子量,利用差示扫描量热分析(DSC)和热失重分析(TGA)研究了聚合物的热性能,利用紫外-可见光谱(UVVis)研究了偶氮聚芳醚酮的光谱学性能. 相似文献
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利用各种芳基格氏试剂与四氟乙烯在四氢呋喃中的反应,合成了六个取代三氟苯乙烯,其中取代基分别为:p-CH_3O,p-CH_3,m-CH_3,p-Cl,m-Cl和m-CF_3,还合成了α-与β-三氟萘乙烯. 研究了在已合成的取代三氟苯乙烯化合物(1)中取代基的电子效应对~(19)F NMR参数的影响.建立了取代基的Hammett常数σ分别与下列~(19)F NMR参数间的线性相关关系;化学位移δ(F~1)-δ(F~2)、偶合常数J_12及化学位移之差Δδ_(3-1)=δ(F~3)-δ(F~1)(或者Δδ_(3-2),证实了过去的预计.建议以Δδ_(3-1)值作为衡量三氟乙烯类化合物中π键极化程度的尺度.并把这一定量的“歪电子云”概念与有关的化学事实联系起来. 相似文献
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In this paper, silica microspheres were used as template to prepare porous fluorinated polyimide (FPI) thin films from polyamic acid (PAA, precursor of FPI) and silica colloid solution. The strong hydrogen-bonding interaction between silica microspheres and PAA chains have improved the dispersion of silica microspheres in N,N-Dimethylformamide (DMF) solution, resulting in the high weight content of silica template in PAA/silica colloid solution, and thus giving rise to the formation of porous FPI films with maximum porosity of 35%. The interior microstructures of the resultant porous FPI thin films were investigated. It is found that the porous FPI thin films have interconnected “ink-bottle-type” porous structure, and the pore size, porosity could be precisely controlled by the diameter and weight content of silica microspheres, respectively. Although both the tensile strength and young modules declined with the increasing porosity, the high level void of the porous FPI films endowed the FPI ultralow dielectric constant of 1.84 when the porosity increased to 35%. Furthermore, the mechanical and dielectric properties of the porous FPI films were closely related to the microstructures and porosity, indicating the desired properties could be controlled to meet the application in the microelectronics. 相似文献
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The temperature dependence of dielectric constants and splay elastic constants for fluorinated phenyl bicyclohexane (PBC) binary liquid crystal (LC) mixtures is reported. The results show that the proportions of the constituent elements of binary mixtures strongly influence their anisotropic dielectric constants. For mixtures in which meta-para- and ortho-para-fluorine-substituted molecules are in equal proportion, the effectiveness of the anisotropic dielectric is equal to that with a single para-fluorine- substituted compound. The proportions of a mixture seldom affect the threshold voltage and splay elastic constants in an anti-parallel measurement cell. 相似文献
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Hui Zhao Si‐Qi Zhao Guo‐Hua Hu Qun‐Chao Zhang Yang Liu Chong‐Xing Huang Wei Li Tao Jiang Shuang‐Fei Wang 《先进技术聚合物》2019,30(9):2313-2320
A facile method was developed to synthesize a new type of polyhedral oligomeric silsesquioxane (POSS). It contained a single amine group and seven aliphatic moieties on its corners. FT‐IR, 1H‐NMR, 13C‐NMR, 13C‐1H COSY, and 1H‐1H COSY confirmed that cages with eight corners were the main part of the product. This new POSS was used to modify the structure of hexamethylene diisocyanate trimer and then copolymerized with hexamethylene diisocyanate and poly (tetramethylene glycol) to get a serious of waterborne polyurethane (WPU)/POSS hybrid materials with low dielectric constants for microelectronics applications. The results showed that POSS particles were uniformly dispersed in the WPU dispersions. The WPU/POSS films did not show any macrophase separation, even when the POSS content was as high as 16%. As the POSS content increased from 0% to 16%, the tensile strength was increased from 2.3 to 7.3 MPa, the dielectric constant was decreased from about 2.9 to 2.0, and the thermal stability of the WPU/POSS was also improved. 相似文献
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联苯型[11], [14]和[17]环系氮杂支链套索冠醚的合成 总被引:4,自引:0,他引:4
以碳酸钾为缩合剂, 2,2'-二羟基联苯分别与二对甲苯磺酸酯Ⅱa~c, Ⅳb,Ⅵb反应合成尚未见文献报道的联苯型单氮杂冠醚(1~3), 二氮杂冠醚9和11。3,9和11分别用氢溴酸去对甲苯磺酰基得到亚胺型氮杂冠醚4, 10和12。4与溴代烃RBr(R=-(CH2)3CH3, -CH2CH=CH2, -(CH2)7CH3, -(CH2)2O(CH2)2OC4H9)反应分别合成[11]环系氮支套索冠醚(5~8), 12与正溴丁烷反应合成[17]环系氮支冠醚13。以上13种化合物皆为新型未见文献报道, 其结构皆经元素分析, IR, ^1H NMR,MS确证。 相似文献
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《Journal of polymer science. Part A, Polymer chemistry》2018,56(5):549-559
A series of novel ultralow dielectric porous polyimide (PI) films containing adamantane groups was prepared via the thermolysis of polyethylene glycol (PEG) oligomers mixed into PI matrix. Scanning electron microscopy results indicated that the porous PI films showed closed pores with an average diameter of 120 ± 10 nm. Good thermal properties with 5% weight loss temperature of 499 °C in air atmosphere and glass transition temperature in excess of 310 °C were shown for porous PI films. Notably, the ultralow dielectric constant of porous PI films with 1.85 at 1 MHz was obtained and revealed via broadband dielectric spectroscopy. The effects of the chemical structure of the PI matrix and PEG content on the decomposition behavior of PEG and the performance of porous films were investigated. Wide‐angle X‐ray diffraction results indicated that the PI matrix with large d‐spacing generated weaker interactions between the PEG and PI backbone than those of PI matrix with small d‐spacing. As a result, the PEG for the PI matrix with large d‐spacing was completely decomposed. As indicated by the broadband dielectric spectroscopy results, lower dielectric porous PI films were prepared when the PEG contents in the PI matrix increased from 0 to 20 wt %. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 549–559 相似文献
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Single-walled carbon nanotubes (SWCNTs) are dispersed in (4’-fluoro phenyl azo) phenyl-4-yl 3-[N-(4’-n-hecyloxy 2-hydroxybenzylidene)amino]-2-methylbenzoate (6–2M-F) a bent-core nematic (BCN) liquid crystalline medium composed of bent-shaped molecules with short core, reduced bend angle possessing polar fluoro substituent in longitudinal direction and methyl group in bent direction. Such molecules are at the borderline of typical bent-core and rod-like molecules resembling hockey stick shape with intermediate properties. The elastic anisotropy is negative for 6–2M-F (bend elastic constant K33 < splay elastic constant K11); similar to other BCNs reported earlier with smectic-like clusters; but turns to high positive (K33 > K11) value by insertion of SWCNT (concentration ≥0.05 wt.%) in 6–2 M-F. The ratio of K33/K11 becomes comparable to the calamitic liquid crystals (LCs) in doped system. Dielectric anisotropy increases in the nanocomposite implying enhanced nematic ordering due to π–π electron interaction between CNTs and the LC molecules. Threshold voltage at first increases and then decreases with increasing CNT concentration owing to the respective variations in splay viscosity of the system. The present study demonstrated the interaction of SWCNTs with BCN molecules and reveals significant modifications in viscoelastic, dielectric and ionic properties of the host. 相似文献
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Yu Shao Yan‐Feng Li Xin Zhao Xiao‐Long Wang Tao Ma Feng‐Chun Yang 《Journal of polymer science. Part A, Polymer chemistry》2006,44(23):6836-6846
A new aromatic, unsymmetrical ether diamine with a trifluoromethyl pendent group, 1,4‐(2′‐trifluoromethyl‐4′,4″‐diaminodiphenoxy)benzene, was successfully synthesized in three steps with hydroquinone as a starting material and polymerized with various aromatic tetracarboxylic acid dianhydrides, including 4,4′‐oxydiphthalic anhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, 2,2′‐bis(3,4‐dicarboxyphenyl)‐hexafluoropropane dianhydride, and pyromellitic dianhydride, via a conventional two‐step thermal or chemical imidization method to produce a series of fluorinated polyimides. The polyimides were characterized with solubility tests, viscosity measurements, IR, 1H NMR, and 13C NMR spectroscopy, X‐ray diffraction studies, and thermogravimetric analysis. The polyimides had inherent viscosities of 0.56–0.77 dL/g and were easily dissolved in both polar, aprotic solvents and common, low‐boiling‐point solvents. The resulting strong and flexible polyimide films exhibited excellent thermal stability, with decomposition temperatures (at 5% weight loss) above 522 °C and glass‐transition temperatures in the range of 232–272 °C. Moreover, the polymer films showed outstanding mechanical properties, with tensile strengths of 74.5–121.7 MPa, elongations at break of 6–13%, and initial moduli of 1.46–1.95 GPa, and good dielectric properties, with low dielectric constants of 1.82–2.53 at 10 MHz. Wide‐angle X‐ray diffraction measurements revealed that these polyimides were predominantly amorphous. These outstanding combined features ensure that the polymers are desirable candidate materials for advanced microelectronic applications. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6836–6846, 2006 相似文献
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A solid acid, phospho-tungstic acid (PTA), has been used to catalyze the pentaerythritol-melamine phosphate (PER-MP) reaction to synthesize intumescent flame retardant, melamine salt of pentaerythritol phosphate (MPP) used in flame retardant polypropylene (PP). This novel and environmentally friendly synthesis technology well solves the problems of conventional preparation methods. PTA plays a double-role: on one hand, it remarkably enhances the conversion of the above reaction and decreases the reaction temperature; on the other hand, it acts as an effective synergist with MPP and greatly improves the flame retardancy; accordingly, no additional process is needed to remove PTA after the reaction, and the products of the catalyzed reaction were directly incorporated with PP to prepare high-performance flame retardant materials. The catalytic and synergistic effects of PTA, as well as the flame retardancy and mechanical properties of the corresponding flame retardant PP were investigated. 相似文献
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D. Boese H. Lee D. Y. Yoon J. D. Swalen J. F. Rabolt 《Journal of Polymer Science.Polymer Physics》1992,30(12):1321-1327
Thin films of poly(p-phenylene biphenyltetracarboximide) (BPDA-PDA), prepared by thermal imidization of the precursor poly(amic acid) on substrates, have been investigated by optical waveguide, ultraviolet-visible (UV-VIS), infrared (IR), and dielectric spectroscopies. The polyimide films exhibit an extraordinarily large anisotropy in the refractive indices with the in-plane index n∥ = 1.806 and the out-of-plane index n⊥ = 1.589 at 1064 nm wavelength. No discernible effect of the film thickness on this optical anisotropy is found between films of ca. 2.1 and ca. 7.8 μm thickness. This large birefringence is attributed to the preferential orientation of the biphenyltetracarboximide moieties with their planes parallel to the film surface, coupled with the strong preference of BPDA-PDA chains to align along the film plane. The frequency dispersion of the in-plane refractive index n∥ is consistent with the results calculated by the Lorentz–Lorenz equation from the UV-visible spectrum exhibiting several absorption bands in the 170–500 nm region. The contribution from the IR absorption in the range 7000–400 cm,?1 computed by the Spitzer-Kleinmann dispersion relations from the measured spectra, adds ca. 0.046 to the in-plane refractive index n∥. Tilt-angle–dependent polarized IR results indicate nearly the same increase for the out-of-plane index n⊥. Application of the Maxwell relation then leads to the out-of-plane dielectric constant ε⊥ ? 2.7 at 1.2 × 1013 Hz, as compared with the measured value of ca. 3.0 at 106 Hz. Assuming this small difference to remain the same for the in-plane dielectric constants ε∥, we obtain a very large anisotropy in the dielectric properties of these polyimide films with the estimated in-plane dielectric constant ε∥ ? 3.4 at 1.2 × 1013 Hz, and ε∥ ? 3.7 at 106 Hz. © 1992 John Wiley & Sons, Inc. 相似文献