共查询到19条相似文献,搜索用时 62 毫秒
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杂质对六氯环三聚磷腈热聚合的影响 总被引:1,自引:0,他引:1
利用红外光谱、磷核磁共振谱、广角X射线衍射、差示扫描量热、凝胶色谱等分析手段,研究了六氯环三聚磷腈(HCCP)在存放过程中产生的杂质,以及不同纯化方法对这些杂质的去除效果,探讨了这些杂质对HCCP单体真空热开环聚合反应的影响.HCCP在存放过程中接触空气中的水汽在环上氯基团处易被水解,产生Trimer-1、Gem-2、Dimmer-3等杂质,重结晶能去除Gem-2、Dimmer-3和少量的Trimer-1,升华能较好地去除Trimer-1.杂质Gem-2、Dimmer-3中的羟基引发聚二氯磷腈交联,生成不可溶的交联态聚二氯磷腈,而Trimer-1则会降低聚合速度,并在聚合物中引入磷氧基和亚胺基杂链,从而影响后续聚磷腈取代产物的性质,表现为聚合物中晶态发生变异,结晶度降低,玻璃化温度、晶态转化温度和熔融温度出现差别.用重结晶结合升华的方法对HCCP单体进行纯化后,应用FTIR或31P-NMR分析来验证纯化效果,以确保能控制聚合速度和时间,使聚合顺利进行. 相似文献
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研究了聚二乙氧基磷腈(PEOP)的制备方法,对合成有机磷腈高聚物的Allcock法进行了改进;表征并研究了PEOP膜对O-2、N_2、H_2、CO_2、CH_4等气体的透过性能。结果表明:在严格的实验条件下,可得到线型结构的PEOP,产率高于Allcock法,达50%左右,所得PEOP为无色透明弹性体,具有良好的成膜性,其膜具有较高的气体透过系数和分离系数,是一类有潜在应用前景的新型膜分离材料。 相似文献
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以双螺环取代三聚磷腈基双苯甲酰氯和4-氨基(N-苯基)苯并噁嗪单体为原料合成了一种含双螺环取代三聚磷腈结构单元的苯并噁嗪树脂单体(HCP-5);采用傅立叶变换红外光谱仪(FT-IR)和核磁共振谱仪(1 H NMR,13 C NMR,31P NMR)表征了苯并噁嗪树脂单体的结构,基于FT-IR和示差扫描量热法研究了其固化行为,并利用热重分析和示差热重分析研究了HCP-5树脂单体、均聚物及其与双酚A型苯并噁嗪树脂(Bz)共聚物的热稳定性.结果表明,HCP-5均聚物具有很好的热稳定性和成炭性,其在317℃下的热失重为5%,在800℃下的残炭率为50%,可用于普通苯并噁嗪树脂改性.此外,HCP-5/Bz(1∶1;质量分数)共聚物在332℃下的热失重为5%,在800℃下的残炭率为48%. 相似文献
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为了得到具有核酸切割功能的人工核酸酶, 设计合成了5种环三聚磷腈多齿配体, 并初步检测了其对DNA的切割活性. 目标化合物的结构由IR, 1H NMR, 31P NMR, 13C NMR和ESI-MS确认. 在生理条件下对pUC19 DNA切割活性的初步实验结果表明, 在化合物5a~5e的Cu(Ⅱ)配合物存在下, 保温24 h后, pUC19 DNA由Form Ⅰ断裂为Form Ⅱ, 即合成目标化合物有明显的DNA切割活性. 同时, 考察了配合物5b+Cu在不同时间下对DNA的切割活性的影响. 相似文献
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氯化钪-氯化钠-氯化钾熔盐制备新工艺研究 总被引:3,自引:1,他引:3
研究了以Sc2O3为原料,盐酸回流溶解后与NaCl,KCl,NH4Cl溶液混合,经蒸发浓缩、结晶、真空预脱水,再在氩气保护下分段升温脱水、升华除去过量NI-hCl后制备ScCl3-NaCl-KCl熔盐的新工艺。研究表明,添加NH4Cl后加热脱水时,NH4Cl分解产生的HCl气体能抑制ScCl3水合物加热过程中的水解,溶解产生的水不溶性钪,从而有效地防止了Sc2O3等水不溶化合物的生成。制备的ScCl3-NaCl-KCl熔盐脱水完全、水不溶性钪含量很低,能满足熔盐金属热还原法制备金属钪及铝钪中间合金对熔盐原料的要求。 相似文献
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Dr. Ernst‐Christian Koch Prof. Dr. Stanisław Cudziło 《Angewandte Chemie (International ed. in English)》2016,55(49):15439-15442
The potential of phosphorus(V) nitride, P3N5 , as a replacement for red phosphorus, PR, in pyrotechnic obscurants has been theoretically and experimentally investigated. P3N5 can be safely mixed with KNO3 and even KClO3 and KClO4 . The corresponding formulations are surprisingly insensitive to friction and only mildly impact‐sensitive. P3N5 /KNO3 pyrolants with ξ=20–80 wt % P3N5 burn 200 times faster than the corresponding mixtures based on PR and generate a dense smoke. Hence obscurants based on P3N5 /KNO3 have a figure of merit that by far exceeds that of current state‐of‐the‐art PR‐based obscurants. Furthermore, unlike PR, which slowly degrades in moist air to phosphoric acids and phosphine (PH3), P3N5 is stable under these conditions and does not produce any acids or PH3 . P3N5 is hence a safe, stable, and powerful replacement for PR for use in insensitive munitions. 相似文献
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Sebastian Vogel Amalina T. Buda Prof. Dr. Wolfgang Schnick 《Angewandte Chemie (International ed. in English)》2018,57(40):13202-13205
Owing to intriguing materials properties non‐metal nitrides are of special interest for both, solid‐state chemistry and materials science. Mixed ternary non‐metal nitrides, however, have only been sparsely investigated, as preparative chemistry lacks a systematic access, yet. Herein, we report on the highly condensed boron phosphorus nitride BP3N6, which was synthesized from (PNCl2)3, NH4N3 and h‐BN in a high‐pressure high‐temperature reaction. By increasing partial pressure of HCl during synthesis using NH4Cl, single‐crystals of BP3N6 up to 80 μm in length were obtained. The unprecedented framework‐type structure determined by single‐crystal XRD blends structural motifs of both, α‐P3N5 and c‐BN, rendering BP3N6 a double nitride. The compound was further investigated by Rietveld refinement, EDX, temperature‐dependent PXRD, FTIR and solid‐state NMR spectroscopy. The formation of BP3N6 through use of reactive precursors exemplifies an innovative access to mixed non‐metal nitrides. 相似文献
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Phenols are easily converted to the corresponding aryl chlorides by using phosphorus pentachloride (PCl5) and a catalytic amount of phenylphosphonic dichloride (PhPOCl2), which is a new efficient method for synthesis of aryl chloride in good yields. 相似文献
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Alexey Marchuk Florian J. Pucher Friedrich W. Karau Prof. Dr. Wolfgang Schnick 《Angewandte Chemie (International ed. in English)》2014,53(9):2469-2472
Phosphorus nitride imide, PN(NH), is of great scientific importance because it is isosteric with silica (SiO2). Accordingly, a varied structural diversity could be expected. However, only one polymorph of PN(NH) has been reported thus far. Herein, we report on the synthesis and structural investigation of the first high‐pressure polymorph of phosphorus nitride imide, β‐PN(NH); the compound has been synthesized using the multianvil technique. By adding catalytic amounts of NH4Cl as a mineralizer, it became possible to grow single crystals of β‐PN(NH), which allowed the first complete structural elucidation of a highly condensed phosphorus nitride from single‐crystal X‐ray diffraction data. The structure was confirmed by FTIR and 31P and 1H solid‐state NMR spectroscopy. We are confident that high‐pressure/high‐temperature reactions could lead to new polymorphs of PN(NH) containing five‐fold‐ or even six‐fold‐coordinated phosphorus atoms and thus rivalling or even surpassing the structural variety of SiO2. 相似文献
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Simon D. Kloß Wolfgang Schnick 《Angewandte Chemie (International ed. in English)》2019,58(24):7933-7944
Nitridophosphates and phosphorus nitrides are thoroughly investigated classes of nitrides. During thirty years of research, the methods for their synthesis evolved from the condensation of molecular precursors at moderate temperatures and ambient pressures to state‐of‐the‐art high‐pressure and high‐temperature processes. Landmark breakthroughs made in recent years led to a comprehension‐based proficiency in nitridophosphate synthesis that is illustrated by the large compositional and structural diversity of the nitridophosphates known today. Herein, we review the advances made in synthesis with regard to the prevalent problem of nitride synthesis: the susceptibility of nitride ions to oxidation. 相似文献
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Chandra S. Sharma Brajesh K. Jha Padam N. Nagar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2259-2267
Phosphorus trichloride and thiophosphoryl chloride derivatives of alkylene dithiophosphates of the type PCl3 ? n () n and P(S)Cl3? n () n (where G = -CH2CH2CHMe-, -CMe2CMe2-, -CH2CH2CH2CH2- and -CMe2CH2 CHMe-, n = 1, 2, 3] have been synthesized for the first time by reacting the ammonium salt of alkylene dithiophosphoric acid with phosphorus trichloride and thiophosphoryl chloride in different stoichiometric ratios under anhydrous reaction conditions. The newly synthesized derivatives are either colorless liquids or viscous semisolids, hygroscopic in nature and are soluble in common organic solvents. These are characterized by elemental analysis, molecular weight determinations and physicochemical studies IR, NMR (1H and 31P). On the basis of above studies the formation of P-S-P and S = P–S–P(S) chemical linkages have been established. 231P NMR studies provide convincing evidence regarding the chemical bonding mode in these derivatives. 相似文献
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近年来, 有机废水对环境造成的污染已经引起了广泛的关注. 吸附法操作简单, 已经被广泛用于处理染料废水.通过在类石墨相氮化碳(g-C3N4)上用氯化锂(LiCl)插层制备了一系列Li/GCN-x复合材料, 并采用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、N2-吸脱附、场发射扫描电子显微镜(SEM)以及X射线光电子能谱(XPS)等对所得吸附剂的形貌和结构进行了表征. 测试结果表明, g-C3N4具有明显的层状结构, 使得LiCl在层间能够稳定地生长. LiCl的加入使得g-C3N4晶格膨胀, 层间距扩大, 表明LiCl成功插层. 此外, 插层后Li/GCN的比表面积远大于g-C3N4, 扩大的比表面积以及形成的 π 共轭体系使得Li/GCN在吸附方面具有较大的潜力. 通过控制实验条件, 研究了Li/GCN对有机染料亚甲基蓝(MB)的吸附性能. 结果表明, Li/GCN-5吸附剂在pH为6时, 5 min吸附量可达704 mg•g–1. 通过动力学拟合, Li/GCN对MB的吸附过程是由准二级动力学模型占主导地位. 进一步通过Weber-Morris模型探究吸附控制过程, 结果表明MB的吸附由表面扩散和孔内扩散共同作用, 其中表面扩散占主导, 且新增官能团与MB分子间可形成氢键, 并通过π-π键相互作用增强吸附能力. 采用共混热聚合法所制备的Li/GCN吸附剂具有稳定、均一、比表面积大等优点, 且简单快速地实现对MB的吸附, 克服了常用吸附剂动力学缓慢的缺点, 为该材料的工业化应用提供一定的借鉴. 相似文献