- Inexpensive synthesis of 1,4-bis(4-aminophenoxy)-2- (6-oxido-6H-dibenz oxaphosphorin-6-yl) phenylene and its oxygen-plasma resistant polyamides
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Inexpensive synthesis of diamine, 1,4-bis(4-nitrophenoxy)-2-(6-oxido-6H-dibenz oxaphosphorin-6-yl) phenylene was revealed in this work. Based on the diamine, a series of organosoluble polyamides were prepared by direct polycondensation of the diamine with various aromatic diacids using triphenyl phosphite and pyridine as condensing agents. The number-average molecular weights of the resulting polyamides range from 4.2?×?104 to 10.5?×?104?g/mol, and the weight-average molecular weights are in the range of 7.5-28.2?×?104?g/mol. The Tgs of these polyamides range from 210 to 255?°C by dynamic mechanical analysis. The resulting polyamides are tough and flexible with tensile strength, elongation at break and moduli range from 84 to 101?MPa, 4.8-7.0%, and 2.36-3.22?GPa, respectively. The degradation temperatures (Td 5%) and char yields at 800?°C in nitrogen range from 460 to 486?°C and 59-68?wt%, respectively. The cutoff wavelength of these polyamides falls in the range of 345-366?nm, showing a very light color characteristic. In addition, these polyamides display good oxygen plasma resistance.
- Lin, Ching Hsuan,Chang, Sheng Lung,Fang, Yu Ting,Hwang, Hann Jang,Tsai, Cheng Hsien
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- Green synthesis of symmetric aryl ether dinitro compounds in deep eutectic solvents
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A series of symmetric aryl ether dinitro compounds were synthesized by 4Urea/ZnCl2 as green solvent and catalyst, and halogenated aromatic hydrocarbon derivatives and dihydroxy compounds as raw materials. This method has the advantages of easy operation, simple recrystallization, environmental friendliness and biodegradability. The structures of the products were subjected to 1H NMR, and the reaction conditions, reaction mechanism and greening advantages of deep eutectic solvents were discussed at the end of the experiments. We learned from the results of the experiments that both the aliphatic dihydroxy compounds and the aromatic dihydroxy compounds could proceed effectively in Ullmann reaction, and the desired products could be obtained in acceptable yields. When using this methodology, symmetric aryl ether dinitro compounds could be synthesized simply at 80oC in 2 h with high yields (66%~94%). Meanwhile, the DES, called deep eutectic solvent which is composed of 4Urea/ZnCl2, could be recycled at least five times without an obvious decraese in the catalytic activity.
- Jin, Yan,Ding, Yinhao,Hou, Xichao,Dong, Jingjing,Lu, Jianqiang,Feng, Baicheng
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p. 101 - 107
(2020/03/17)
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- A double 1, 4 - (4 - nitrophenoxy) benzene mechanical chemical synthesis method (by machine translation)
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The invention relates to a 1, 4 - double-(4 - nitrophenoxy) benzene mechanical chemical synthesis method, in particular to a metal salt catalytic lower mechanical force to promote of hydroquinone with the nitro relevent aniline synthesis of 1, 4 - double-(4 - nitrophenoxy) benzene green synthesis method. The specific method is: the ball mill pot and adding hydroquinone and nitro relevent aniline, then adding catalyst, alkali, silica gel and grinding ball, mechanical chemical reaction, after the reaction, the organic solvent used for the transfer of the reaction mixture, filtering the insoluble matter, the filtrate is concentrated by recrystallization, to obtain yellow-green crystal product 1, 4 - double-(4 - nitrophenoxy) benzene. The advantage of this invention lies in simple operation, reaction time is short, the atom economy is high, the resulting high product yield, purity of 99% or more, and is suitable for industrial use. (by machine translation)
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Paragraph 0020-0032
(2019/10/04)
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- Oxidative and Reductive Cross-Coupling Reactions Catalyzed by an Anionic "ligandless" Palladium Complex
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The anionic complex [NBu4][Pd(DMSO)Cl3], which can be synthesized on a gram scale in a single step starting from commercially available starting materials, has been shown to be an active catalyst in the Mizoroki-Heck reaction of aryl halides. We present two new catalytic applications of this complex: the base-free oxidative Heck reaction and the reductive homodimerization of aryl halides. This complex outperformed other palladium salts. In the latter reaction, the catalyst loading could be reduced to 0.01 mol %. The scope of the reactions has been explored, demonstrating the potential of the anionic palladium complex in these catalytic transformations.
- Schroeter, Felix,Lerch, Swantje,Strassner, Thomas
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supporting information
p. 1614 - 1621
(2019/01/04)
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- Functionalized MWCNTs, an efficient reinforcement for the preparation of eugenol based high performance PBz/BMI/CNT nanocomposites exhibiting outstanding thermo-mechanical properties
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The chemistry of benzoxazine synthesis offers wide molecular design flexibility and thus facilitates preparation of various polybenzoxazine based composites. In this paper, we reported the preparation of polybenzoxazine/BMI blend and subsequent preparation of nanocomposites with amine functionalized multiwalled carbon nanotubes (F-MWCNTs). The curing mechanism and the material properties of the blend and nanocomposites were studied extensively. DSC analysis showed two exothermic maxima, corresponding to benzoxazine and allyl group polymerization. Furthermore, by the incorporation of F-MWCNTs into the PBz/BMI system, the properties of the PBz/BMI/F-MWCNT nanocomposites were improved significantly. The enhancement in the material properties is due to the strong interaction between the F-MWCNTs and PBz, resulting in the formation of interpenetrating polymer networks. The morphology and fracture surface of the nanocomposites were studied by scanning electron microscopy. The thermal, mechanical and dielectric properties of the nanocomposites are found to be outstanding when compared with the neat PBz and PBz/BMI blend.
- Periyasamy, Thirukumaran,Asrafali, Shakila Parveen,Kim, Seong-Cheol
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p. 6607 - 6615
(2017/07/17)
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- Thermal transition behaviors, solubility, and mechanical properties of wholly aromatic para -, meta -poly(ether-amide)s: Effect on numbers of para -aryl ether linkages
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In order to make clear how the numbers of para-aryl ether linkages affect the solubility, thermal transition behavior and mechanical properties of para-(p-PEAs), meta-poly(ether-amide)s (m-PEAs), a series of para-substituted aryl ether diamine monomers with 2, 3, 4 or 5 ether linkages were synthesized, and then reacted with terephthalic acid and isophthalic acid via the Yamazaki-Higashi phosphorylation method to prepare wholly aromatic PEAs. The PEAs with intrinsic viscosity values in the range of 0.81-1.16 dL g-1 were obtained and characterized by FT-IR, NMR, and elemental analysis. Although the Tgs and Tms of PEAs decrease with the increasing numbers of aryl ether linkages, their Tgs and Tms still are above 180 °C and 320 °C, respectively. p-PEAs have a high crystallinity making it difficult to dissolve them in common organic solvents even when 5 aryl ether linkages are introduced. Conversely, except for m-PEA5 with a lower polarity, the other m-PEAs show good solubility due to their low crystallinity. Besides, the decomposition temperatures at 5% weight loss of all PEAs exceed 430 °C and their residual yields at 700 °C are above 50% in N2, illustrating that they have excellent thermal stability. It is found that by casting m-PEAs DMAc solution in a dish, the transparent films with high Young's modulus (2.6-3.5 GPa) can be successfully obtained.
- Zhang, Wen-Qiang,Wang, Xiu-Li,Liu, Gui-Cheng,Chen, Li,Wang, Yu-Zhong
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p. 84284 - 84293
(2016/10/12)
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- Novel diisocyano-based dinuclear gold(I) complexes with aggregation-induced emission and mechanochromism characteristics
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A series of constitutional isomers containing dinuclear gold(I) units were designed, synthesized and characterized using IR spectrometry, NMR spectroscopy and elemental analysis. The aggregation-induced emission (AIE) characteristics of the complexes were investigated by photoluminescence (PL) and UV/Vis spectroscopy. The results indicated that gold(I) complexes 1-3 exhibited significant AIE phenomena. PL spectroscopy, used to probe their solid-state mechanochromic properties, suggested ortho-isomer luminogen 1 exhibited reversible mechanochromic fluorescence, whereas meta-isomer luminogen 2 showed switchable mechanical force-induced luminescence enhancement behavior. No mechanochromism behavior was observed for para-isomer luminogen 3. Powder X-ray diffraction indicated that the morphology phase conversion between crystalline and amorphous states is responsible for the mechanochromism or mechanical force-induced emission enhancement characteristics.
- Chen, Zhao,Li, Zheng,Yang, Lan,Liang, Jinhua,Yin, Jun,Yu, Guang-Ao,Liu, Sheng Hua
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p. 170 - 177
(2015/06/16)
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- Synthesis and characterization of novel bio-based benzoxazines from eugenol
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Polybenzoxazines are phenolic-like materials that possess dimensional and thermal stability, and they release no by-products during their polymerization. In this study, a new class of benzoxazine-containing monomers has been prepared from renewable resource (eugenol, a natural phenol obtained from clove oil), paraformaldehyde and various aromatic diamines. The structures of the monomers were supported by Fourier Transform Infrared (FT-IR), 1H-NMR and 13C-NMR spectral analysis, proving the existence of the benzoxazine ring containing eugenol moiety in its molecular structure. The monomers were polymerized/cured via ring-opening polymerization by heating as indicated by FT-IR and Differential Scanning Calorimetry (DSC). This is confirmed by the disappearance of the peaks due to oxazine ring (942 cm-1). The exothermic peak associated with curing was observed from 170°C to 250°C. The thermal and mechanical properties of the polybenzoxazines were investigated through thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The temperatures corresponding to 5% and 10% weight loss is from 240 to 295°C and from 290 to 340°C, respectively. The completely cured materials could achieve char yields up to 36.5% at 800°C in nitrogen atmosphere. DMA revealed that the glass transition temperatures of PBz-SUL and PBz-PHE were higher than that of PBz-DDS and PBz-OXY.
- Thirukumaran,Shakila,Muthusamy, Sarojadevi
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p. 7959 - 7966
(2014/02/14)
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- Selective monoarylation of benzenediols via dianion intermediates
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Application of the SNAr reaction on benzenediols with arylfluorides revealed an enhancement in monosubstitution selectivity over bis substitution when excess base was used. This trend was studied using symmetrical and nonsymmetrical benzenediols with vari
- Xie, Chaoyu,Sullivan, Kevin A.,Laurila, Michael E.,Mitchell, David N.,Pu, Y. John
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- Synthesis of Monosubstituted Polynuclear Phenols Containing a Nitrophenoxy Fragment
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A numbers of monosubstituted polynuclear phenols have been synthesized by reaction of p-chloronitrobenzene or m-dinitrobenzene with various bisphenols.
- Dorogov,Derevyagin,Budanov,Plakhtinskii,Kotov
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p. 655 - 657
(2007/10/03)
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- Process for preparing nitrodiphenyl (thio) ethers
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Nitrodiphenyl(thio) ethers in which the nitro group is in the ortho- or para-position with respect to the ether oxygen or ether sulphur can be prepared from halonitrobenzones in which the nitro group is in the ortho- or para-position with respect to the halogen and, alkali metal (thio)phenolates in liquid ammonia, the reaction being carried out under pressure and at a temperature from -30° C. to +140° C. and the ammonia being separated off after the reaction is completed.
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