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151.
Kazunori Se Masato Kijima Reiko Ohtomo Teruo Fujimoto 《Journal of polymer science. Part A, Polymer chemistry》1997,35(7):1219-1226
The Menschutkin reaction of three poly(tertiary aminostyrene)s: poly(N,N-dimethyl-4-vinylphenylamine) (PPA), poly(N,N-dimethyl-4-vinylbenzylamine) (PBA), and poly(N,N-dimethyl-4-vinylphenethylamine) (PPTA) was investigated. These three polymers having narrow molecular weight distributions were prepared via anionic living polymerization. PPA reacted homogeneously with n-butyl bromide in N,N-dimethylformamide (DMF). PBA and PPTA also reacted homogeneously with n-butyl bromide in a mixture of DMF/methanol (75/25 v/v %). GPC measurement of the quaternized polymers was carried out using a mixture of water/acetonitrile (80/20 v/v %) containing 0.5M acetic acid and 0.3M sodium sulfate (pH = 2.9) as an eluant in order to suppress adsorption of the quaternized water soluble polymers on GPC gel. Results of GPC measurement indicate that the polymer chains of the three poly(tertiary aminostyrene)s are neither severed nor crosslinked in the process of quaternization. Temperature dependence and reaction time dependence on the degree of quaternization (DQ) were studied for PPT, PBA, and PPTA. By altering reaction time and temperature, the DQ values of the three poly(tertiary aminostyrene)s could be controlled in the range from 0% to nearly 100%. Quaternization reactivity of the amino groups in the three polymers was found to decrease in the order, PPTA, PBA, and PPA. The differences in reactivity are thought to be attributable to the electron density on the nitrogen atom of the N,N-dimethylamino group, and steric hindrance in the vicinity of the nitrogen atom. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1219–1226, 1997 相似文献
152.
In this study, sodium benzoate was selected as the nucleating agent to improve the crystallization rate of Poly (Ethylene Terephthalate) (PET). A new polyester, PEAT, which was systhesized from Bis Hydroxy-Ethyl Terephthalate (BHET) and adipic acid, was blended with PET to improve the (crystallization) rate of PET at lower temperatures. The crystallization rate of the PET blends was measured with a DSC and the kinetics of crystallization were studied. It was found that the range of the crystallization temperatures for the PET/sodium benzoate blends was wider than that for the PET/PEAT blends which shifted to a lower temperature region. PEAT showed a pronounced effect on the crystallization rate at lower temperatures, while sodium benzoate effected the crystallization rate within the entire range of crystallization temperatures. 相似文献
153.
154.
人工神经网络紫外吸收光谱法测定安钠咖注射液各组分 总被引:4,自引:0,他引:4
应用人工神经网络原理,采用误差反向传播方法,对紫外吸收光谱重叠的安钠咖注射液中咖啡因和苯甲酸钠含量进行测定.实验表明,人工神经网络法对上述两组分含量测定结果准确,探讨了人工神经网络参数对分析结果的影响. 相似文献
155.
Michael G. Ikonomou Blair D. Surridge 《International journal of environmental analytical chemistry》2013,93(2):183-198
Two of the most common products currently used to control parasitic sea lice in fin fish aquaculture, salmon in particular, are Slice® and AlphaMax®. Emamectin benzoate (EB) is the active ingredient in Slice® and deltamethrin is the active ingredient in AlphaMax®. Several analytical methods have been developed for the determination of the active ingredients in these products but these have been focused on specific matrices and lack the sensitivity and versatility required in environmental monitoring. Here we present a validated, versatile, and simple analytical method for the determination of EB, its desmethyl degradation product (AB), and deltamethrin in a wide range of environmental matrices (sea water, marine sediment, and tissue). Sediments and tissues were extracted by accelerated solvent extraction (ASE®) and sample cleanup was achieved by solid phase extraction (SPE) while sea water was extracted using SPE disks. Analyte identification and quantification was based on liquid chromatography tandem mass spectrometry (LC-MS/MS) instrumentation with electrospray ionization, and multiple reaction monitoring (MRM). Method detection limits for the target analytes was in the parts per trillion (pg?g?1) level for tissue and sediment and parts per quadrillion (pg?L?1) for water. Except for deltamethrin in sea water, method performance in terms of analyte recoveries was better than 60%, and the method precision was RSD<20%. The method was used to determine EB and AB concentrations in water, sediment and prawn tissue samples collected near salmon aquaculture sites treated with Slice®. A distinct concentration gradient was observed in the immediate vicinity (within 50 to 100?m radius) of the salmon aquaculture sites where EB was detected at low ng?g?1 levels for tissue (EB ranged from 0.041 to 3.0?ng?g?1) and sediment (EB ranged from 0.051 to 35?ng?g?1) and pg?L?1 levels (EB ranged from 3 to 209?pg?L?1) for water samples. 相似文献
156.
157.
反相高效液相色谱法同时测定食品中甜蜜素、糖精钠和苯甲酸钠 总被引:9,自引:0,他引:9
采用反相高效液相色谱法快速分离和测定食品中甜蜜素、糖精钠和苯甲酸钠,在ODS柱上,以30%甲醇和70%(含离子对试剂)水溶液为流动相进行分离;分别考察了流动相中不同的甲醇配比和不同浓度的离子对试剂对分离和保留行为的影响。检测波长为205nm。采用外标法定量。该方法精密度高、准确度好,样品处理简单,实用于常规质量监测。 相似文献
158.
ZHANG Zhi-gang ** WU Hong-cai LIU Xiao-zeng YI Wen-hui Institute of Photoelectric Technology Solar Energy School of Electronic Information Engineering Xi′an Jiaotong University Xi′an P. R. China 《高等学校化学研究》2005,21(2):166-168
Introduction Nonlinearoptical(NLO)organicpolymers havereceivedincreasingattentionbecauseoftheir excellentbehaviorandthegoodprospectsoftheir applicationsinhigh-techareas,suchasoptical communication,high-densityopticalstorageand all-opticalinformationprocess.Poly(pyrrolylme- thine)isanNLOmaterialwithpromisingapplica- tions[1_3].However,itssolubilityandfilm-forming performancearepoor.Inthispaper,anovelsolu- blepoly(pyrrolylmethine),poly[(3-octanoyl-pyr- role-2,5-diyl)-p-(N,N-dimethylamino)ben… 相似文献
159.
《Journal of Coordination Chemistry》2012,65(3):529-547
Six new Ln(III) complexes viz., [Gd(tptz)(SCN)3(CH3OH)2OH2]·CH3OH (1), [Eu(tptz)(SCN)3(CH3OH)2OH2]·CH3OH (2), [Tb(tptz)(SCN)3(OH2)3]4 (3), [Gd(tptz)(OBz)2(μ-OBz)OH2]2·2H2O (4), [OH2(OBz)2(tptz)Eu1(μ-OBz)2Eu2(tptz)(OBz)2OH2]·CH3OH·7H2O (5), and {[Tb1(tptz)(OBz)2(μ-OBz)]2·[Tb2(tptz)(OBz)3CH3OH]2}·2CH3OH·4H2O (6) (Ln = Gd, Eu, Tb; tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine; BzONa = sodium benzoate), have been synthesized and characterized by physicochemical methods including single-crystal X-ray crystallography. The X-ray studies demonstrate that 1–3 are mononuclear, whereas 4–6 are binuclear. The photophysical properties of 1–6 have been studied with ultraviolet absorption and emission spectral studies. Their thermal properties have been studied by thermogravimetric (TG) and derivative thermogravimetric analysis (DTG), demonstrating that the final product after decomposition was Ln2O3 for all these complexes. 相似文献
160.
以邻硝基苯胺和间苯二酚为原料,经重氮化-偶合、环化、酯化合成了6个新型苯甲酸(苯并三唑基)苯酯类化合物:3-羟基-4-苯并三唑基-4′-硝基苯甲酸苯酯(58.6%)、3-羟基-4-苯并三唑基-2′-硝基苯甲酸苯酯(60.7%)、3-羟基-4-苯并三唑基-3′-硝基苯甲酸苯酯(55.7%)、3-羟基-4-苯并三唑基-3′,5′-二硝基苯甲酸苯酯(62.1%)、3-羟基-4-苯并三唑基-2′-羟基苯甲酸苯酯(48.6%)和3-羟基-4-苯并三唑基-2′-羟基-3′,5′-二硝基苯甲酸苯酯(52.2%)。通过1H-NMR、FT-IR和MS确定了这些化合物的分子结构,紫外光谱测试表明它们均具有较好的紫外吸收性能。 相似文献