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以柠糠酸酐为原料, 合成了一种可以与丙烯腈(AN, acrylonitrile)共聚的新单体: 2-甲基-2-丁烯二酸单甲酯(MBAME). 以偶氮二异丁腈(AIBN, 2,2’-azobis isobutyronitrile)为引发剂, 70 ℃下引发MBAME与AN在N,N-二甲基甲酰胺(DMF, N,N-dimethylformamide)中进行无规共聚, 通过Fineman-Ross法测定了两者在DMF溶液聚合体系的表观竞聚率, γ1(AN)=7.985, γ2(MBAME)=0.599, 有助于优化聚丙烯腈基碳纤维用树脂的生产工艺. 相似文献
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(一)4-溴代-丁腈與苯隣二羧醯-鉀亞胺在乙醇中互相作用卽得4-(苯隣二羧醯-亞氨基)-丁腈。 (二)4-(苯隣二羧醯-亞氨基)-丁腈與硫化氫起作用卽得4-(苯隣二羧醯-亞氨基)-丁硫醯胺。 (三)4-(苯隣二羧醯-亞氨基)-丁硫醯胺與1,3-二氯代丙酮縮合則成2-(γ-苯隣二羧醯-亞氨基)-正丙基-4-氯代-甲基-噻唑。 (四)2-(γ-苯隣二羧醯-亞氨基)-正丙基-4-氯代-甲基-噻唑與二乙胺起作用卽成2-(γ-苯隣二羧醯-亞氨基)-正丙基-4-N-二乙氨基-甲基-噻唑。後者與聯氨水合物起作用形成2-γ-氨基-正丙基-4-N-二乙氨基-甲基-噻唑。 相似文献
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高容量分子印迹聚合物的制备及表征 总被引:1,自引:0,他引:1
以α-甲基丙烯酸和4-乙烯基吡啶为二元功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,氯仿为致孔剂用本体聚合法合成了甲磺隆分子印迹三元共聚物,并用固相萃取方法对该聚合物在有机相及水相中的键合容量进行了评价,与同一条件用单一单体合成的聚合物的键合容量进行了比较,发现该三元共聚物在有机相中每克聚合物可键合20.5 mg的甲磺隆分子,水相中每克聚合物可键合19.2 mg的甲磺隆分子.采用核磁滴定对三元共聚体系的预聚溶液中分子作用力进行了研究,发现三元体系的预聚溶液中分子间作用力引起的位移变化幅度比二元体系的预聚溶液的变化大很多,这说明形成了更强的作用位点. 相似文献
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二氧化碳-环氧乙烷-氧化环己烯三元共聚物的制备与性能 总被引:2,自引:0,他引:2
采用稀土三元催化剂实现了二氧化碳、氧化环己烯与环氧乙烷的三元共聚,当环氧乙烷和氧化环己烯等摩尔投料时催化活性达到690 g/(mol Zn h),所得三元共聚物的数均分子量达到7.9×104,远程异核多量子相关核磁谱证明所得共聚物主要是无规三元共聚物,其中环氧乙烷-二氧化碳结构单元与氧化环己烯-二氧化碳结构单元相连的全交替结构占26.9%.二氧化碳-氧化环己烯共聚物的脆性导致其熔体加工十分困难,引入环氧乙烷为第三单体进行三元共聚,实现了二氧化碳-氧化环己烯共聚物的增韧,解决了其熔体加工难题,而且改变环氧单体比率能够调节三元共聚物的耐温性能和力学性能,当环氧乙烷与氧化环己烯等摩尔投料时,所得三元共聚物在20℃下的杨氏模量达到(900±17)MPa,拉伸强度为(38±2)MPa,断裂伸长率为(26.3±9.2)%. 相似文献
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Surface acidity of aluminium oxide containing 5 wt. % lanthanum oxide has been determined by IR spectroscopy. Strength of Lewis sites of the La2O3/Al2O3 system was lower than that of pure aluminium oxide. However, the presence of La2O3 in aluminium oxide increased the thermostability of these sites in the mixed system. 相似文献
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一些具有NASICON型网格结构的固体电解质具有高的电导率和好的稳定性,NASICON的意思是Na Super Ionic Conductor[1]。当NaZr2(PO4)3中P5 被Si4 部分取代时便可以得到具有NASICON结构的Na1 xZr2SixP3-xO12体系,其具有高的钠离子电导率。然而有相同结构的Li1 xZr2SixP3-xO12体系的离子电导率却很低,这是因为Li 半径太小,而NASICON三维网格结构的离子通道太大,两者不匹配而使电导率下降[2]。但当LiZr2(PO4)3中Zr4 被离子半径小些的Ti4 取代,所得LiTi2(PO4)3的通道就与Li 半径相匹配,适合于锂离子的迁移,从而使其电导率… 相似文献
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P. K. Penskoi V. F. Kostryukov S. V. Kutsev I. V. Kuznetsova V. R. Pshestanchik I. Ya. Mittova 《Russian Journal of Inorganic Chemistry》2009,54(10):1564-1570
Chemistimilated thermal oxidation of gallium arsenide was studied using Sb2O3 activator oxide in compositions with Ga2O3, Al2O3, and Y2O3 inert components. For Sb2O3-Y2O3 compositions, the thickness of the resulting oxide layer on GaAs was found to be a linear function of composition over the
enter range of the compositions. For antimony oxide compositions with Ga2O3 and Al2O3 inert components, nonadditivities were observed near the component ordinates. For the Sb2O3-Ga2O3 system, the chemistimulating efficiency noticeably weakened at low concentrations of the inert component. The linear trend
observed for this system within 0–60 mol % Sb2O3 is additively determined by the oxide layer thickness on GaAs in the presence of Sb2O3 and in the absence of activator. In the presence of inert Al2O3, the chemistimulating effect was enhanced near the Al2O3 ordinate and the resulting function was nonadditive with respect to the thicknesses reached in the presence of the individual
components. 相似文献
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The compounds Ba3Re2O9 and Sr3Re2O9 were prepared by the solid state reaction of the corresponding alkaline-earth oxide with ReO3 at 750 to 900°C in sealed, evacuated, fused silica tubes. The two compounds are isostructural, having the nine-layer ABO3 structure with vacant central octahedra. The unit cell parameters are given. The magnetic susceptibility for Ba3Re2O9 indicates Curie-Weiss behavior with a Re6+ moment having localized electrons. The magnetic data for Sr3Re2O9 suggest delocalized electron behavior from its temperature-independent susceptibility. Both compounds appear to have semiconducting properties, but the strontium analog is a better conductor. Both compounds are unstable when heated in air above 400°C. They are readily decomposed by chemical oxidizing agents. 相似文献
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Al2O3-TiO2二元氧化物的制备条件对酸性的影响 总被引:5,自引:0,他引:5
用两种方法制备了Al2O3-TiO2二元氧化物。经不同温度焙烧后,用Hammett指示剂滴定法、吡啶吸附IR法、正丁胺——TPD法对其表面酸性质进行了测定。结果表明:随着Al2O3含量增加,Al2O3-TiO2二元氧化物的总酸量、酸强度和L酸比例都增加;随着焙浇温度的增大,总酸量下降,L酸比例和酸强度较大的酸量、百分数则增加。 相似文献
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Differential scanning calorimetry and high temperature oxide melt solution calorimetry are used to study enthalpy of phase transition and enthalpies of formation of Cu2P2O7 and Cu3(P2O6OH)2. α-Cu2P2O7 is reversibly transformed to β-Cu2P2O7 at 338–363 K with an enthalpy of phase transition of 0.15 ± 0.03 kJ mol−1. Enthalpies of formation from oxides of α-Cu2P2O7 and Cu3(P2O6OH)2 are −279.0 ± 1.4 kJ mol−1 and −538.8 ± 2.7 kJ mol−1, and their standard enthalpies of formation (enthalpy of formation from elements) are −2096.1 ± 4.3 kJ mol−1 and −4302.7 ± 6.7 kJ mol−1, respectively. The presence of hydrogen in diphosphate groups changes the geometry of Cu(II) and decreases acid–base interaction between oxide components in Cu3(P2O6OH)2, thus decreasing its thermodynamic stability. 相似文献
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向Pt-Pd/CeO2-ZrO2-Al2O3 (Pt-Pd/CZA)商用柴油机氧化型催化剂(DOC)中加入多孔SiO2以提高其抗硫性. 使用多层涂覆法在Pt-Pd/CZA 催化剂表面覆盖一层多孔SiO2,从而制得SiO2/Pt-Pd/CeO2-ZrO2-Al2O3(SiO2/Pt-Pd/CZA)抗硫DOC. 并使用扫描电子显微镜(SEM),H2程序升温还原(H2-TPR),氮气吸脱附,X射线能谱(EDX)和热重分析(TGA)等对其进行表征. SEM结果显示,SiO2层以多孔形式均匀覆盖在催化剂表面. 氮气吸脱附结果表明,所添加的SiO2的织构性质与Pt-Pd/CZA 催化剂的织构性质相似,因而表面覆盖的SiO2并未明显改变Pt-Pd/CZA催化剂的比表面积和孔结构. H2-TPR结果证实表面覆盖的SiO2不影响Pt-Pd/CZA催化剂的还原性能. EDX和TGA结果说明表面覆盖SiO2可以抑制硫物种在催化剂表面的形成及累积. 最终,本文所制备的SiO2/Pt-Pd/CZA催化剂在保持Pt-Pd/CZA商用DOC的高活性及耐久性的同时有效提高了其抗硫性. 相似文献
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W. Li M. Wang Z. H. Li X. F. Shang H. Wang Y. W. Wang Y. B. Xu 《Russian Journal of Electrochemistry》2007,43(11):1279-1283
The lithium-ion-conducting inorganic solid electrolytes in the oxide systems Li2O-SiO2-P2O5 and Li2O-TiO2-SiO2-P2O5 were prepared by the solid-state reaction, and the electrolyte pellet made by cold-pressing method had diameter of 13 mm
and was about 1 mm thick. Phase identification and surface morphology of the products were carried out by X-ray diffraction
and scanning electron microscopy. Ionic conductivity of the pellets was investigated through ac impedance. The results show
that the adding of other cations can improve the ionic conductivity of the solid electrolyte, and the sintering temperature
and duration can influence the ionic conductivity. The maximum ionic conductivity in the samples is 9.9 × 10−4 S/cm in the Li2O-TiO2-SiO2-P2O5 system.
Original Russian Text ? W. Li, M. Wang, Z.H. Li, X.F. Shang, H. Wang, Y.W. Wang, Y.B. Xu, 2007, published in Elektrokhimiya,
2007, Vol. 43, No. 11, pp. 1341–1345. 相似文献
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Films of Y2O3, La2O3, and La2CuO4 were prepared by an ultrasonic nebulization and pyrolysis method using acetylacetonates of the corresponding metals in alcohol solvents as source materials. Homogeneous, uniform films with good adherence have been obtained using this simple technique. As-deposited yttrium and lanthanum oxide films were poorly crystallized. After postannealing in oxygen at higher temperature, they crystallized into cubic and hexagonal phases, respectively. Transparent yttrium and lanthanum oxide films have high electric breakdown voltages. Single phase polycrystalline La2CuO4 thin films were obtained from a source solution with a La:Cu ratio of 2:1. 相似文献
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Takatsugu Masuda Cara L. Nygren Kunimitsu Uchinokura 《Journal of solid state chemistry》2003,176(1):175-179
The structure of Cu2Fe2Ge4O13, previously thought to be CuFeGe2O6, has been determined from single-crystal X-ray diffraction data to be monoclinic, P21/m, a=12.1050(6), b=8.5073(4), c=4.8736(2) Å, β=96.145(1)°, Z=2, with R1=0.0231 and wR2=0.0605. The unique structure has an oligomer of four germanate tetrahedra, cross-linked laterally by square-planar copper ions, joined end-to-end by a zigzag chain of edge-sharing iron oxide octahedra. Running along the a-direction the metal oxide chain consists of alternating Cu-Cu and Fe-Fe dimers. A hypothetical series of homologous structures (Cun−2Fe2GenO3n+1 with n=3,4,…,∞) with different length germanate oligomers is proposed, where as n increases, the infinite chain of the CuGeO3 is approached. In this context, Cu2Fe2Ge4O13 is viewed as being built from blocks of CuGeO3 and the Fe oxide chains. This material has significance to the study of low-dimensional mixed-spin systems. 相似文献