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以二苯硫醚为主要原料,以过氧化氢为氧化剂,在室温条件下氧化得到了二苯亚砜.然后,二苯亚砜与二苯硫醚在硫酸的作用下,进行缩合反应制备了双[(4-二苯硫)苯]硫醚-双-六氟磷酸盐,收率由文献报道的39%提高到75%;对其结构进行了UV、IR、H NMR和元素分析. 相似文献
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聚对苯硫醚[poly(pphenylenesulfide),简称pPPS]的分子链是由对苯撑基和硫原子交替连接构成而使制品抗冲击能力差[1](有些研究者用共聚或共混的方法在pPPS中引入间位结构来达到减少其结晶度,增强韧性的目的)。余自力等[2]用硫磺溶液法合成了mPPS、pPPS及其共聚物,认为在pP... 相似文献
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以氟苯和氯化亚砜反应合成了4,4’-二氟二苯亚砜,并将其与4,4’二羟基二苯硫醚在N-甲基吡咯烷酮溶剂中进行亲核取代反应合成了聚苯醚硫醚醚亚砜,用乙二酰氯/四丁基碘化铵还原该亚砜聚合物制备了聚苯醚硫醚。用红外光谱和核磁共振谱对合成单体的结构进行了确认,同时对聚合物进行了红外光谱、核磁共振、元素分析、X射线光电子能谱、X射线衍射、DSC分析、TG/DTG以及溶解性测试。结果表明聚苯醚硫醚样品具有氧醚和硫醚交替的线性结构,特性粘度为0.55 dL/g的PPSE熔点达236℃,在氮气条件下,样品起始分解温度和最大分解速率处温度分别为359℃和514℃,在700℃时的重量保留率为43.3%,且在加热条件下能溶解于N-甲基吡咯烷酮(NMP)、二甲基乙酰胺(DMAc)、二甲基甲酰胺(DMF)等极性有机溶剂中。 相似文献
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三配位磷化物与烷氧基苯硫醚反应合成了一系列含磷五元环的五配位化合物。在不同温度下,测定了这些化合物的19FNMR。化合物(7)与三氟乙氧基苯硫醚反应生成化合物(19)以及(20)和(21);化合物(11)与六氟异丙氧基苯硫醚反应生成化合物(18)和(21),并对这些反应机理进行了讨论。 相似文献
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用X射线衍射法快速测定聚对次苯基硫醚的结晶度Ⅱ. 总被引:1,自引:0,他引:1
本文报道用X射线衍射测定聚对次苯基硫醚(pps)结晶度的一个快速测定方法:即选择(110)峰和峰的积分面积与对应的非晶散射峰的积分面积代表它们的强度来计算聚对次苯基硫醚的结晶度,利用这个方法测定了聚对次苯基硫醚原粉和在不同温度下热处理后样品的结晶度,最后得到了比较满意的结果。 相似文献
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以P2O5为脱水剂,甲烷磺酸为溶剂,二苯亚砜与二苯硫醚反应制备了(4-苯硫基-苯基)二苯基硫六氟磷酸盐.对产物进行了元素分析、紫外光谱、红外光谱、气-质联用和核磁共振的结构确证.该硫盐对环氧树脂具有良好的固化性能. 相似文献
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聚硫醚醚酮(砜)芳香环状低聚物的合成与自由基开环聚合 总被引:1,自引:0,他引:1
在“拟高稀释”条件下,通过亲核缩聚反应高产率地合成了含硫醚键的芳香醚环状低聚物.应用核磁、GPC和激光质谱(MALDI-TOFMS)等手段对环状低聚物的结构进行了确认,并研究了环状低聚物的组分分布.聚硫醚醚酮环状低聚物在硫醚自由基的引发下进行快速熔融聚合,得到热稳定性很好的高分子量线性聚合物. 相似文献
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本文考虑了含二重螺轴或滑移面的体系由二聚体构造长链体系定性能带的方法, 讨论了一些有代表性的体系如顺式聚乙炔、扭角不为零的聚对苯撑、聚吡咯及其类似物的导电性问题, 与孤子理论进行了联系, 进一步说明从二聚体可以获得长链体系的信息。 相似文献
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Ribonucleic acid (RNA) polycytidine (poly rC) homopolymer thin films were prepared on highly oriented pyrolytic graphite (HOPG) substrates. The films were grown from aqueous solution directly in a vacuum in multiple steps with use of an electrospray (ES) deposition system. Before poly rC deposition and after each deposition step the sample was characterized with X-ray and ultraviolet photoemission spectroscopy (XPS, UPS). Evaluation of the UP-spectra sequence allowed the determination of ionization energy and highest occupied molecular orbital (HOMO) electronic structure, as well as the charge injection barriers between HOPG and poly rC. Comparison with earlier results on polyadenosine (poly rA) indicates significant differences between ionization energies (poly rC: 8.1 eV; poly rA: 6.8 eV) and orbital alignment at the graphite interface. The larger ionization energy of poly rC results in a larger hole injection barrier and a smaller electron injection barrier relative to the HOPG Fermi level. 相似文献
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以低不饱和度环氧丙烷聚醚三元醇与L型及DL型丙交酯为原料, 合成了不同单体物质的量比的聚醚与聚乳酸嵌段共聚物. 采用FTIR, 1H NMR, GPC对共聚物的结构进行了表征; 用DSC, DTA对共聚物的玻璃化转变温度、熔点及热分解温度进行了研究. 结果表明, 丙交酯在聚醚多元醇端羟基的引发下发生开环反应, 得到聚环氧丙烷L型乳酸(POLLA)或聚环氧丙烷DL型乳酸(PODLA)二嵌段共聚物. POLLA二嵌段共聚物具有结晶能力, 且随着L型聚乳酸链段的增长而增强. PODLA二嵌段共聚物为非晶态聚合物. 两种共聚物的玻璃化转变温度与共聚物的组成有关, 其值介于聚醚和聚乳酸玻璃化转变温度之间. 与聚醚三元醇相比, 二嵌段共聚物的耐热性得到提高, 其热分解温度提高了30~60 ℃, 约为235~262 ℃. 共聚物的结构和组成对材料的热降解机制有很大影响. PODLA在高温区发生热氧化降解. 相似文献
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氢化松香与HEMA酯化物自聚与共聚研究 总被引:3,自引:0,他引:3
用氢化松香(HR)与甲基丙烯酸-2-羟乙酯(HEMA)进行酯化反应,得到了酯化物(HRH),然后对其进行了在甲苯中的自由基自聚反应、以及与甲基丙烯酸甲酯(MMA)或与苯乙烯(St)的共聚反应,制备了自聚物和共聚物,用IR和核磁共振氢谱(1HNMR)对产物进行了表征,用综合热分析仪表征了产物的热稳定性和玻璃化转变温度.结果表明:成功合成了HRH自聚物(PolyHRH)、以及共聚物[Poly(HRH-co-St)和Poly(HRH-co-MMA)].产物的热稳定性顺序为:HRH>PolyHRH>Poly(HRH-co-St)>Poly(HRH-co-MMA). 相似文献
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用紧束缚近似的EHMO方法对αMTDTPY.TCNQ(1)、β-MTDTPY.TCNQ(2)及MTDTPY.CHL(3)三种电荷转移复合物晶体的电子能带进行了计算。在1中,电子施体(D)分子MTDTPY及受体(A)分子TCNQ形成交替重叠的一维分子柱(M),柱间无净电荷转移。能隙E~G=0.15eV,载流子的产生主要来自热激发。在2及3中,电子施体(D)MTDTPY及受体(A)TCNQ及CHL分子分别相对独立的D及A一维分子柱,载流子的产生主要来自柱间的电荷转移。由电子能带结构及关于载流子迁移的Frohlich-Sewell公式,得出上述三种晶体的室温电导率之比为σ1:σ2:σ3=3.75×10^-^1^0:1:1.15,与实验事实基本一致。关于各分子柱对σ的贡献,2中D柱:A柱~10^3:1;3中D柱:A柱~2:1。根据计算结果,本文还对载流子的迁移机理进行了讨论。 相似文献
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V. Maleev M. SemenovV. Kashpur T. BolbukhA. Shestopalova D. Anishchenko 《Journal of Molecular Structure》2002,605(1):51-61
The aim of this paper is to summarize the original results concerned with the elucidation of the role of water environment in the formation of different structures of polyribocytidylic acid (poly(rC)), depending on the pH, temperature and ion content. To solve this problem, we studied the hydration of poly(rC)-K+ in films differing in water content, by methods of infrared spectroscopy and piezogravimetry, and in solution, using the dielectric measurements at a wavelength of 7.6 mm (extremely high frequencies — EHF). The experimental results were confirmed by a Monte Carlo simulation of the interaction between water molecules and single-strand and double-strand poly(rC) fragments in clusters of 800 water molecules. A model of hydration of double-strand complex of poly(rC)+-poly(rC) has been proposed based on our results and the known X-ray parameters of the complex. The obtained results and proposed structure of poly(rC)+-poly(rC) suggest that, the stabilization of this complex occurs due to intra- and inter-chain water bridges, together with the hydrogen bonds between neutral and protonated cytosines in pairs. 相似文献
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Hydrophobic organic-inorganic hybrid monolithic columns were synthesized via thermally initiated free radical polymerization with the confines of 75 μm id capillary using a polyhedral oligomeric silsesquioxane (POSS) reagent containing eight or more methacrylate groups as the crosslinker. Three organic functional monomers, butyl methacrylate (BuMA), lauryl methacrylate (LMA) and methacrylic acid (MAA), were selected and copolymerized with the POSS in the presence of 1-propanol and 1,4-butanediol to prepare the poly(POSS-co-BuMA), poly(POSS-co-LMA), and poly(POSS-co-MAA) monoliths, respectively. The 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was copolymerized as ionizable monomer into the poly(POSS-co-BuMA) and poly(POSS-co-LMA) for the generation of EOF in capillary electrochromatography (CEC). A hybrid poly(POSS-co-LMA-co-MAA) monolith was also similarly prepared by copolymerizing ternary monomers of POSS, LMA, and MAA, and compared with poly(POSS-co-BuMA), poly(POSS-co-LMA), and poly(POSS-co-MAA) monoliths. The resulting four kinds of POSS-contained hybrid monoliths exhibited good permeability and mechanical stability. Their column efficiencies were evaluated by the separation of alkylbenzene homologues and polar compounds in CEC. The results indicated that the highest efficiencies of 194,100 and 102,100 theoretical plates per meter for thiourea and benzene were obtained on the poly(POSS-co-LMA-co-MAA) monolith. Additionally, the poly(POSS-co-LMA-co-MAA) monolith exhibited better selectivity for separation of polar compounds than those of other hybrid monoliths. 相似文献