含乙氧甲酰甲氨基咪唑杯[4]芳烃的合成及其水相体系中对Al3+和Ag+的荧光识别

该文以二溴丁氧基杯[4]芳烃和取代的1H-咪唑为原料合成了乙氧甲酰甲氨基咪唑杯[4]芳烃(M),采用红外、核磁、质谱对所合成化合物进行了结构表征;采用紫外吸收光谱和荧光发射光谱,在体积比为3∶7的甲醇/水混合溶液(Tris-HCl缓冲溶液,pH=6.5)中考察了M对常见金属离子的识别性能。结果发现,化合物M以1∶1的络合比对Al~(3+)进行选择性识别,且识别行为不受其他常见金属离子的干扰;化合物M以1∶2的络合比与Ag~+络合,当Al~(3+)作为干扰离子且浓度高于Ag~+时,对M与Ag~+的识别产生干扰。即,当Al~(3+)和Ag~+同时存在时,化合物M与Al~(3+)具有更好的识别选择性。     

辛二酸盐成核改性等规聚丙烯的研究

采用DSC、WAXD、PLM等分析手段研究了辛二酸和辛二酸盐对等规聚丙(烯iPP)结晶行为的影响。结果表明:辛二酸、辛二酸锂、辛二酸钠、辛二酸钾、辛二酸镁、辛二酸钡和辛二酸锌都不是β晶成核剂,辛二酸锶和辛二酸镉是弱β晶成核剂,辛二酸钙是强β晶成核剂。通过分析结晶温度发现,辛二酸和辛二酸盐对iPP成核能力的大小顺序为:辛二酸>辛二酸钙>辛二酸镁>辛二酸锌>辛二酸钾>辛二酸镉>辛二酸钡>辛二酸钠>辛二酸锶>辛二酸锂。     

化工产品标准中滴定测试方法的设计初步(九)——络合滴定法

<正> 络合滴定法是以络合反应为基础的滴定分析方法。络合剂具有氨基氮■和羧基氧■的配位原子,即氨羧络合剂。用的最多的是乙二胺四乙酸二钠,简写成 EDTA 二钠,或 EDTA。它可以和二价、三价、四价金属离子生成较稳定的、配比关系均为1比1的络合物,络合反应的速度较快、在化工产品中用络合滴定法测定金属盐和部分阴离子。本文先简单地介绍设计络合滴定分析法的基本要求,再按不同的滴     

有机硅匀泡剂合成中铂系催化剂性能的研究

研究了氯铂酸催化剂体系的制备及Si-C型有机硅匀泡剂合成中硅氢加成反应工艺。在氯铂酸催化剂作用下，使含有Si-H的聚硅氧烷和烯丙基聚醚进行加成反应，温度控制在110±5 ℃为宜；制备了氯铂酸-异丙醇催化剂和氯铂酸-二乙基聚硅氧烷络合型催化剂，比较了在硅氢加成反应中的催化活性。结果表明，使用络合型Karstedt催化剂后，铂用量减少(<10 μg-Pt·g-1)，产品质量指标提高。     

电镀污泥酸浸出液中铜含量的测定

介绍了电镀污泥酸浸出液中铜含量的测定方法:在适宜条件下,铜(Ⅱ)与双环己酮乙二酰二腙形成稳定的蓝色络合物,该络合物对600 nm波长的可见光有最大吸收峰;试液中共存铁(Ⅲ)的干扰用柠檬酸三铵掩蔽,镍(Ⅱ)的干扰通过控制显色体系的pH为8.3,使之不与双环己酮乙二酰二腙络合显色而消除,锌(Ⅱ)不与双环己酮乙二酰二腙络合显色。该方法不需要分离,直接依次加入相关试剂掩蔽、调节酸度和显色即可直接进行分光光度法测定,具有简便、快速且准确的特点。用该方法测定配制的标准混合溶液中的铜含量以检验其准确性。将该方法与间接碘量法的测定结果采用t-检验法进行检验以考察是否存在系统误差。     

荧光探针测定乙交酯中总质子浓度

以氟化硼络合二吡咯甲川类(BODIPY)染料为荧光团,正丁胺为识别体,合成了一种新型酸敏感的BODIPY类荧光探针。通过研究荧光探针对乙醇酸浓度的光谱行为,建立了荧光光谱法测定乙交酯中总质子浓度的方法。结果表明,乙醇酸浓度在0.2~1.2 mmol/L范围内,体系荧光强度呈线性关系,其线性方程为Y=71.4+180.5×103c(mol/L),相关系数r为0.998 9,检出限为0.3μmol/L,乙交酯中总质子浓度检测结果令人满意。     

酶法转化体系中L-苯丙氨酸的络合萃取

L-苯丙氨酸的分离提取对于促进酶法制备工艺的产业化进程具有重要价值。利用络合萃取分配系数、分离选择性高的特点,对苯丙酮酸酶法制备L-苯丙氨酸转化体系中L-苯丙氨酸的络合萃取进行了研究。以二(2-乙基己基)磷酸为萃取剂,研究了水相平衡pH、萃取剂浓度和稀释剂的种类对分配系数的影响;并利用D2EHPA-正辛醇体系对酶法制备L-苯丙氨酸的转化液进行了络合萃取研究,经4次萃取和1次反萃,L-苯丙氨酸的萃取率达到98 15%;经1次反萃,L-苯丙氨酸的收率达94 33%。     

N,N-二亚甲基膦酸基甘氨酸的络合滴定

N,N-二亚甲基膦酸基甘氨酸以下简称NNBPG,亦称增甘膦或二膦甘酸,七十年代问世。在农业上作生长调节剂,有很好的增糖增产效果。化学上用于水处理、除垢、化学镀等,极有应用开发价值。其产品质量检测至关重要。本文基于其络合性质,研究了在pH=10的缓冲溶液中,以锌试剂为指示剂,用锌标准溶液进行络合滴定的分析方法。     

聚普瑞锌的合成

以β-丙氨酸为原料,与O-乙基黄原酸甲酯合成二氢-1,3-噻唑-2,4-二酮,再与L-组氨酸开环酰化得L-肌肽,最后与醋酸锌络合得到聚普瑞锌,总收率58.6%。     

应用技术

<正> 萤光素络合指示剂萤光素络合指示剂(Calcein)又名钙黄绿素,为测定钙、钡、锶、铜、锰等用的有效指示剂。用EDTA 作钙离子的络合滴定是一个快速的容量分析方法,这个方法的关键在于指示剂的选择。选用萤光素络合指示剂来滴定钙时终点明确,对于存在于水中钙和石灰石中钙的测定曾都能得到满意的结果。好多学者曾多次指出用这种指示剂滴定钙时,较经典指示剂紫脲酸铵为佳。R.蒲希比曾明确指出,紫脲酸铵用来滴定镍和铜是比较理想,在滴定钙时终点就难以辨认。铬黑T(Eriochrome Black T)可用来滴定钙、镁和锌等离子,如有铁、钴存在,可使指示剂蔽塞而     

Fingerprinting and characterization of carboxylic acids in in-situ oil shale retort and process waters by capillary column gas chromatography-mass spectrometry

Six important in-situ oil shale retort and process waters have been analysed for carboxylic acids by capillary column gas chromatography-mass spectrometry. A fingerprint or profile was obtained for Occidental boiler blowdown process water, retort water and heater-treater process water; Geokinetics retort water, and Laramie Energy Technology Center Omega-9 and 150 Ton retort waters. The results clearly show significant differences in that each retort or process water contains various mono-, di-, branched, keto-aliphatic and aromatic carboxylic acids. The Occidental retort and process waters contained straight-chain monocarboxylic acids from C₂–C₁₃ and C₂–C₁₄, whereas the Geokinetics retort water contained C₂–C₁₀, the 150 Ton retort water C₂–C₁₀, and Omega-9 retort water C₂–C₁₄ acids. Variations among the retort waters and process waters were more important for the normal dicarboxylic acids. The Occidental retort and process water contained no C₂–C₇ straight-chain dicarboxylic acids, but those from C₈–C₁₂ were present. The Omega-9 retort water contained all the straight-chain dicarboxylic acids, C₂–C₁₂, that were identified, whereas the 150 Ton sample contained only C₂ and C₄ dicarboxylic acids, and the Geokinetics sample C₂–C₄ and C₈–C₁₂ acids. The implications of the results in pyrolysis of oil shale kerogen are discussed.     

Synthesis of octacalcium phosphate with incorporated succinate and suberate ions

Octacalcium phosphate (OCP) has a layered structure composed of apatitic and hydrated layers. HPO₄^2? in the hydrated layer can be substituted by dicarboxylate ions. The synthesis of octacalcium phosphate with incorporated dicarboxylate ions (octacalcium phosphate carboxylate, OCPC), was investigated through the effects of the initial concentration of dicarboxylic acid on the formation of OCPC. Succinic acid (Suc) and suberic acid (Sub) were used as dicarboxylic acids for preparing OCPC, and crystalline phases of the products were characterized by powder X-ray diffraction (XRD). When the amount of added dicarboxylic acid was 1–5 times the amount corresponding to the stoichiometric composition of OCPC, incorporation of dicarboxylate ions progressed with increasing amount of added dicarboxylic acids, although OCP without incorporated dicarboxylate ions was also present. When the amounts of added Suc and Sub were larger than 10 times the stoichiometric amount in OCPC, a single OCPC phase was detected in the powder XRD patterns. Amounts of Suc and Sub greater than 10 times the stoichiometric amounts facilitated formation of the OCPCs and inhibited formation of OCP. The incorporation of dicarboxylate ions into OCP competes with incorporation of HPO₄^2?. Hence a high concentration of dicarboxylic acids is required for complete incorporation of dicarboxylate ions in OCP.     

Oxidation reaction of high molecular weight dicarboxylic acids in sub- and supercritical water

Sebacic and azelaic acids, which are representative of high molecular weight dicarboxylic acids, were oxidized in a batch reactor with H₂O₂ oxidant in water from 300 °C to 400 °C at sub- and supercritical conditions. Intermediate products were identified based on GC–MS, HPLC, and ¹H NMR. The main oxidation products were dicarboxylic acids and the minor products were monocarboxylic acids. (ω − 1)-Keto acids, aldehyde-acids, and γ-lactones with carboxylic groups also were identified.On the basis of the products identified, the oxidation pathways of high molecular weight dicarboxylic acids were formulated. The oxidation of high molecular weight dicarboxylic acids proceed with the consecutive oxidation of higher to lower molecular weight dicarboxylic acids mainly through the oxidation at α-, β-, and γ-carbons to a –COOH group. The oxidation of dicarboxylic acids was also accompanied by oxidative decarboxylation, leading to the formation of monocarboxylic acids.     

Synthesis,characterization, and curing of unsaturated polyamides derived from 2,6-di(4-carboxystyryl)pyridine and 2,6-bis(4-carboxybenzylidene) cyclohexanone

Two new series of heat-curable polyamides were prepared utilizing the unsaturated dicarboxylic acids 2,6-di(4-carboxystyryl)pyridine (DCSP) and 2,6-bis(4-carboxybenzylidene)cyclohexanone (BCBC) as starting materials. They were prepared from the condensation of 4-carboxybenzaldehyde with a half molar amount of 2,6-dimethylpyridine or cyclohexanone, respectively. The dicarboxylic acids reacted with various aromatic diamines, utilizing triphenyl phosphite and pyridine as condensing agents, to yield polyamides. In addition, two model diamides were prepared by condensing the dicarboxylic acids with aniline. Characterization of starting materials, polyamides, and model compounds was accomplished by IR and ¹H–NMR spectroscopy. The curing behavior of polyamides was investigated by DTA. Upon heat-curing, the unsaturated polyamides were crosslinked through their olefinic bonds to afford insoluble, heat-resistant resins. The thermal stability of the resins was evaluated by TGA and isothermal gravimetric analysis (IGA). The cured resins were stable up to 310–322°C in N₂ or air and afforded anaerobic char yield of 57–69% at 800°C.     

Modified poly(ether–imide–amide)s with pendent benzazole structures: Synthesis and characterization

Three series of novel modified poly(ether–imide–amide)s (PEIAs) having pendent benzazole units were prepared from diimide–dicarboxylic acids, including 2-[3,5-bis(4-trimellitimidophenoxy) phenyl]benzimidazole, 2-[3,5-bis(4-trimellitimidophenoxy) phenyl]benzoxazole, and 2-[3,5-bis(4-trimellitimidophenoxy) phenyl]benzothiazole, with various diamines by direct polycondensation in N-methyl-2-pyrrolidone with triphenyl phosphite and pyridine as condensing agents. These new diimide–dicarboxylic acids containing ether linkages and benzazole pendent groups were synthesized by the condensation reaction of 5-(2-benzimidazole)-1,3-bis(4-aminophenoxy)benzene, 5-(2-benzoxazole)-1,3-bis(4-aminophenoxy)benzene, or 5-(2-benzothiazole)-1,3-bis(4-aminophenoxy)benzene with trimellitic anhydride, respectively. All of the polymers were obtained in quantitative yields with inherent viscosities of 0.39–0.65 dL/g. For comparative purposes, the corresponding unsubstituted PEIAs were also prepared by the reaction of a diimide–dicarboxylic acid monomer lacking benzazole pendent groups, namely, 3,5-bis(4-trimellitimidophenoxy) phenyl, with the same diamines under similar conditions. The solubilities of the modified PEIAs in common organic solvents and their thermal stability were enhanced compared to those of the corresponding unmodified PEIAs. The glass-transition temperature, 10% weight loss temperature, and char yields at 800°C were 19–31°C, 22–57°C and 4–8% higher, respectively, than those of the unmodified polymers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

微生物发酵生产长链二元酸

以生物工程技术发酵生产长链二元酸的方法,不但开辟了长链二元酸的新来源,而且解决了一些二元酸无法化学合成的难题。目前,规模化工业生产十二碳二元酸及其衍生产品的装置已经建成投产。     

Extraction properties of phthalic acid and aromatic polycarboxylic acids using various solvents

BACKGROUND: To explore the extraction properties of aromatic acids produced in the oxidation of coal, the extraction equilibrium of phthalic acid (as a typical product) was studied using three solvents, 1‐octanol, 50% tributylphosphate (TBP)/kerosene, and 10% trialkylphosphine oxide (TRPO)/kerosene, and the feasibility of separating phthalic, [1,1′‐biphenyl]‐2,2′‐dicarboxylic and trimellitic acids is discussed. RESULTS: Phthalic acid extraction followed the sequence: 10% TRPO > 50% TBP > 1‐octanol, with recoveries from the TRPO and TBP systems being much larger than that for 1‐octanol. The stoichiometry of formation of the complexes of TBP and TRPO with phthalic acid was 1:1. The apparent extraction equilibrium constant for TRPO is much larger than that for TBP. The distribution coefficient of [1,1′‐biphenyl]‐2,2′‐dicarboxylic acid is much larger than that of the other two acids using 1‐octanol as the extractant and this acid could be removed by 1‐octanol from a mixture of the three acids. The extraction equilibrium correlations obtained for the individual acid component systems can be used to predict that of the acid mixture. CONCLUSION: The extent of phthalic acid extraction by the three solvents investigated is as follows: 10% TRPO > 50% TBP > 1‐octanol. The stoichiometry of the complex formation of TBP or TRPO and phthalic acid is 1:1, and the apparent extraction equilibrium constant for TRPO is much larger than that for TBP. 1‐octanol shows a good extractive selectivity for [1,1′‐biphenyl]‐2,2′‐dicarboxylic acid as compared with phthalic and trimellitic acids. Copyright © 2011 Society of Chemical Industry     

含3,3’,5,5’-四甲基结构的新型聚芳酰胺的合成与表征

摘 要：本文从分子设计的角度出发,以苯甲醛和2,6-二甲基苯胺为原料,经过一步法合成一种含四甲基结构的二胺单体。利用Yamazaki磷酰化法,将自制的二胺单体分别与对苯二甲酸（PTA）、间苯二甲酸(IPA)和二羧基联苯醚(OBA)三种二酸单体经一步缩聚得到了三种新型可溶性芳香聚芳酰胺,特性黏度在0.57~0.84dL/g之间。该聚芳酰胺表现出优异的溶解性能和光学性能：室温下不仅可以溶于高沸点的N-甲基-2-吡咯烷酮（NMP）、N, N-二甲基乙酰胺(DMAc)、N, N-二甲基甲酰胺(DMF)和二甲基亚砜(DMSO)中,还能溶于低沸点的氯仿（CHCl3）等有机溶剂中,而且大部分聚合物在这类溶剂中的溶解度可达10 wt% 以上。所制得的聚芳酰胺薄膜颜色浅、透明性高,截断波长在312~345 nm之间,500 nm处的透过率均超过80%。此外,该系列聚芳酰胺还表现出良好的热学性能和机械性能：玻璃化转变温度在338℃以上,空气和氮气中10%热失重在380℃和408℃以上;其薄膜的拉伸强度、断裂伸长率和起始模量分别在64~81MPa、8.0%~9.2 %和1.4~2.0GPa之间。     

Shifting of the double bond in methyl oleate during hydrogenation

Summary The displacement of the double bond of methyl oleate during hydrogenation with a nickel-kieselguhr catalyst at 180°C. was investigated, particularly with respect to the analysis of dicarboxylic acids, obtained either by oxidation of the reaction products with KMnO₄ in acetic acid or by means of ozone. In the oxidation experiments with KMnO₄ a considerable degradation of lower molecular dicarboxylic acids occurs that makes a quantitative analysis of the isomerization phenomena uncertain. According to the ozonization experiments an equal migration of the double bond in both directions, toward and opposite the ester group, takes place.     

Molecular compounds generated by ruthenium tetroxide oxidation and preparative off line thermochemolysis of lignite humic acids from South Moravia: Implications for molecular structure

The composition of humic acids (HAs) isolated from a South Moravian lignite deposit was examined via thermochemolysis and RuO₄ oxidation. The combination of thermochemolysis with TMAH and TEAAc shows that fatty acids were mostly in a “free” form, tightly trapped within the humic acid organic network. Humic acids contain also trapped hydrocarbons. The relative distributions of these compounds confirm their higher plant origin. RuO₄ oxidation resulted in a lipophilic fraction containing mainly fatty acids. The hydrophilic fractions released upon RuO₄ oxidation comprised mostly aliphatic C₂-C₉ dicarboxylic acids and hydroxy acids related to short methylene bridges, to bridges between aromatic and/or oxygenated moieties such as aliphatic chains of ligneous units.