利用~1H-核磁共振谱计算环化丁苯橡胶的环化度和溶剂参与量

对环化丁苯橡胶的1 H 核磁共振谱进行了归属分析 ,并推导出计算环化度和溶剂参与量的公式。设环化丁苯橡胶的1 H 核磁共振谱图中化学位移为 7 0 ,5 4,4 9和 3 0～ 0处的峰强度分别为A ,B ,C和D ,则环化丁苯橡胶中丁二烯总物质的量 (X) =(B C D - 2A) /7 1 ,未环化的丁二烯物质的量 (Y) =B/2 C/4,参与反应的二甲苯物质的量 (Z) =( 1 7 5A -B -C -D) /46 5,环化度 (P) =1 -Y/X ,溶剂参与量 (W ) =91 6Z/X。     

利用^1H—NMR计算环化氯丁橡胶的环化度和溶剂参与量

对环化氯丁橡胶的＾１Ｈ－ＮＭＲ谱进行了归属,并推导出计算环化氯丁橡胶（ＣＲ）的环化度和溶剂参与量的公式。     

环化丁苯橡胶的表征

在ＳＢＲ中加入环化试剂ＡｌＥｔ２Ｃｌ－Ｃ６Ｈ５ＣＨ２Ｃｌ,在１２０℃,２０ｍｉｎ条件下制备了环化ＳＢＲ,并借助ＩＲ,＾１Ｈ－ＮＭＲ,ＤＳＣ,ＧＰＣ等方法对产物性能进行了表征。结果表明,二国本溶剂参与了环化反应,且随环化度增加,参与反应的二甲苯量也逐渐增加,并确定了环结构的形成。利用＾１Ｈ－ＮＭＲ谱图导出了环化ＳＢＲ的环化度和溶剂参与量的计算公式。     

铁掺杂SiO2非均相催化剂的制备及其烷基化反应研究

以稻壳灰为硅源采用溶胶-凝胶法制备了铁掺杂二氧化硅非均相催化剂,以甲苯与氯化苄的苄基化反应为探针反应,研究了所制备催化剂的催化效果。结果表明,铁掺杂二氧化硅非均相催化剂的BET比表面积、微孔孔容和平均孔径分别为191.98 m2/g,0.010 68 cc/g和10.810 66 nm,当甲苯∶氯化苄∶催化剂的质量比为69.28∶5.72∶0.1,加热回流1.5 h时,产物主要为单苄基甲苯,产率87.5%,重复使用三次后的催化效果变化不大。     

High temperature 1H-NMR study of coal and pitch at the early stages of carbonization

The temperature dependence of the ¹H-NMR absorption in coals and pitches have been obtained using a pulsed Fourier transform NMR spectrometer with a high temperature probe. The samples as received were heated in the high temperature probe and NMR spectra were obtained simultaneously. With increasing temperature, the value of the line width at half-height (ΔH_1/2) of a brown coal decreases and then increases rapidly. On the other hand, tar pitch and the γ component of a coal indicate that the values of ΔH_1/2 remain small over a wide temperature range. It is found that there is an excellent relation between the temperature dependence of ΔH_1/2 and the optical texture of the mesophase.     

A study of solvent motion in acetone-PMMA solutions using 13C and 1H spin-lattice relaxation measurements

The ¹³C and ¹H spin-lattice relaxation times of acetone in solutions containing from 0 to 20% poly(methyl methacrylate) have been measured from ?55°C to 120°C. The ¹³C measurements show that except at low temperature and the higher polymer concentrations, solvent rotation is little affected by the presence of polymer molecules. By assuming that the ¹³C relaxation time is entirely intramolecular in origin, and by progressive deuteration of the acetone, the ¹H relaxation time has been separated into intramolecular, acetone-acetone intermolecular and acetone-polymer intramolecular contributions. These results show that up to 10% of polymer or so does not affect solvent diffusion, but for 20% polymer, solvent diffusion is perceptibly slowed down, and the activation energy increased by 50%. The data give no indication of polymer conformational transitions in this temperature range, as suggested by others elsewhere, but this may be because of the very short-range sensitivity of n.m.r. measurements.     

Synthesis, 1H-NMR and electronic absorption spectra of bis-(1,2-dimethyl-3-indolyl)-hetarylmethane dyes

The synthesis of a series of bis-(1,2-dimethyl-3-indolyl)-hetarylmethane dyes is described where hetaryl is 2-benz-oxazolyl, 2-benzothiazolyl, 1-methyl-2-benzimidazolyl, 4-pyridyl and 2-pyridyl.The 1H-NMR data of these dyes are interpreted, and their electronic absorption spectra as well as those of their protonated forms are discussed. Good correlation of their longwave absorption band shifts relative to the 'unsubstituted' bis-(1,2-dimethyl-3-indolyl)monomethine cyanine with 'second order perturbation' based on HMO calculations could be found.Protonation constants pK* and hydroxylation constants pKR?* are measured.     

乳液插层法制备丁苯橡胶/蒙脱土纳米复合材料的结构与性能

选用一种能够在水中分散良好的有机改性蒙脱土（OMMT），采用乳液插层法制备了SBR／OMMT纳米复合材料，X射线衍射和透射电镜观察显示制得了半剥离型与插层型共存的纳米复合材料。研究了复合材料的力学性能和耐溶剂性能。测试结果表明，随着蒙脱土用量的增加，复合材料的定伸应力、拉伸强度和撕裂强度均大幅度提高。复合材料具有优异的耐溶剂性能。     

Ion and solvent diffusion and ion conduction of PC-DEC and PC-DME binary solvent electrolytes of LiN(SO2CF3)2

Two binary mixed solvent systems typically used for lithium batteries were studied by measuring the self-diffusion coefficients of the solvent, lithium ion and anion, independently by using the multi-nuclear pulsed field-gradient spin-echo (PGSE) , and NMR method. One system was propylene carbonate (PC) and diethyl carbonate (DEC) system and the other binary system was PC and 1,2-dimethoxyethane (DME), and the lithium salt used was LiN(SO₂CF₃)₂ (LiTFSI). The relative ratio of the PC was changed from zero (pure DME and DEC) to 100% (pure PC) in the DME-PC and the DEC-PC systems, respectively. The self-diffusion coefficients of the solvents were measured with and without the lithium salt, and the two solvents had almost the same diffusion coefficient in the DEC-PC system, while DME diffused faster than PC in the DME-PC system. In the electrolytes the solvents diffused the fastest, followed by the anion with the lithium ion diffusing the slowest. The degree of ion dissociation was estimated for each electrolyte by comparing the ionic conductivities estimated from the ion diffusion and those measured directly by the electrochemical method.     

Facile synthesis of isoindoline-1,3-diones by palladium-catalyzed carbonylative cyclization of o-bromobenzoic acid and primary amines

A facile method for the carbonylative cyclization of o-bromobenzoic acid with primary amine using Pd(OAC)₂ as a metal precursor and 1,1'-bis(diphenylphosphino)ferrocene (dppf) as a ligand has been developed. The effect of various reaction parameters such as ligand, solvent, base, time and temperature on this cyclization was studied. The optimized protocol was used for a wide variety of substituted aryl amines with different steric and electronic properties, affording the corresponding isoindoline-1,3-diones in good to excellent yields under atmospheric pressure of carbon monoxide at 100°C within 10 h using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a base. The reaction system finds attractive alternative to the conventional multistep synthetic process and thus represents an effective utilization of carbonylative protocol for synthesis of valuable chemicals.