水体中邻苯二甲酸酯和己二酸酯的气相色谱-质谱分析方法

Phthalates and adipate ester in water have been extracted with n-hexane and analyzed by gas chromatography-mass spectrometry(GC-MS).The mean recoveries ranged from 69% to 109% with their RSD range of 1.96%-10.2%.The research results also showed that the method presented simplicity-operating,excellent linearity and reproducibility.

Influence of adipic acid on anodic film formation and corrosion resistance of 2024 aluminum alloy

The influence of adipic acid on the formation and corrosion resistance of anodic oxide film fabricated on 2024 aluminum alloy was investigated. The morphology was investigated by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, respectively. The corrosion resistance was evaluated by electrochemical impedance spectroscopy （EIS）. The results showed that the adipic acid was absorbed at the electrolyte/anodic layer interface during anodizing. The corrosion rate of anodic film decreased and the film thickness increased. The film was uniform and compact especially at the film/substrate interface. After sealing procedure, anodic film formed with the addition of adipic acid exhibited improved dielectric property and corrosion resistance in aggressive environment.

环己酮绿色氧化合成己二酸质谱分析

己二酸是合成尼龙-66的主要原料,同时在低温润滑油、合成纤维、油漆、聚亚胺酯树脂及食品添加剂的制备等方面也有重要用途,目前己二酸的世界年产量估计已达220万吨.工业上己二酸的生产是以环己烷经两步氧化合成,第一步为环己烷在金属离子催化下用氧气氧化为环己醇、环己酮,第二步用浓HNO3氧化环己醇、环己酮制得己二酸.……

Measurement and Correlation for Solubility of Adipic Acid in Several Solvents

Using a laser detecting system, solubility data were measured for adipic acid dissolved in six pure solvents, namely, cyclohexanone, cyclohexanol, acetic acid, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethylsulfoxide at the temperature range from 293.15K to 353.15K. All these data were regressed by 2h, NRTL, Wilson, and the modified Wilson models. For the study of six, 2h, NRTL, and the modified Wilson models were found to provide an accurate mathematical representation of the experimental results, with overall average absolute relative deviations between measured and calculated values as 1.74%, 2.06%, and 3.06%, respectively. The results showed that the λh model is the most suitable for description of the solid-liquid equilibrium containing adipic acid.

Measurement and Correlation of Solubilities of Adipic Acid in Different Solvents

Using a simple and reliable apparatus, the solubilities of adipic acid in water, ethanol, chloroform, n-butanol and acetone are determined by the analytic method. The results are correlated with λh equation, Apelblat equation, and UNIFAC equation. The solubilities calculated by these models are in good agreement with experi-mental data, so that the models can meet the requirements of engineering design.

Recent advances on controllable and selective catalytic oxidation of cyclohexene

Because of multiple potential reaction sites and variable oxidation depths,oxidation of cyclohexene can lead to a mixture of products with different oxidation states and functional groups,such as 7-oxabicyclo[4.1.0]heptane,trans/cis-cyclohexane-1,2-diol,cyclohex-2-en-1-ol,cyclohex-2-en-1-one,and even adipic acid.These products are broadly and abundantly used intermediates in the chemical industry;therefore,controllable oxidation reactions for cyclohexene that can selectively afford the targeted products are synthetically valuable for applications in both the academy and industry,thus becoming the aim of synthetic and catalytic chemists in the field.Many reports on selective oxidation of cyclohexene have recently appeared in the literature because of its significance.This short review summarizes the recent advances on this subject,and the contents are mainly classified based on the chosen oxidants.We hope that this review can provide a useful guide for controllable and selective catalytic oxidation of cyclohexene for interested readers from both the academy and industry.

Simulation of Continuous Esterification Process of Polyester Polyols

Based on the kinetic and thermodynamic equations, a comprehensive mathematical model for the con- tinuous esterification process of polyester polyols was developed, which was carried out in an innovational bub- bling reactive distillation tower （BRDT） at atmospheric pressure. In this new type of reactor, direct esterification between ethylene glycol and adipic acid was accomplished efficiently and rapidly. A bench BRDT with the height of 2 m was applied for the esteriflcation process of l^oly （ethylene adlpate） （P＇EA）. In the continuous operation, Hn- ear oligomers were discharged from the bottom of the column, while water passed a few column trays and a pack- ing section as a condensation byproduct. The influence of major operating conditions on reactor performance was also simulated. Simulation results were in good agreement with experimental data, providing a strategy for devel- oping and optimizing this process.

Study on Liquid Phase Ammoniation of Adipic Acid to Adiponitrile

The reaction mechanism of the liquid phase ammoniation of adipic acid to adiponitrile was studied experimentally in a semi-batch reactor. Macrokinetics of the main and side reactions were identified to minimize corrosion and coking to prolong the operation period, to increase the yield of adiponitrile and to improve the design of the reactor. Macrokinetic equations of ammoniation-neutralization of adipic acid and dehydration were of first-order to adipic concentration cB≥3.5% and of second order for cB≥3.5%. Catalyst H3PO4 reduced the activation energy of neutralization and dehydration reactions of adipic acid and was significantly important for the second step of dehydration to produce adiponitrile.

Kinetic study for the oxidation of cyclohexanol and cyclohexanone with nitric acid to adipic acid

The adipic acid is an important intermediate in the production of nylon,polyurethane and polye ster resin s.The industrial approach for preparing adipic acid is through the liquid catalytic oxidation of KA oil with nitric acid.In this work,a comprehensive model is developed for this reaction based on the kinetic study conducted in a continuous flow tubular reactor.The kinetic model fits well with the experimental results across the experimental conditions,and the average relative error between the calculated and experimental values is 5.7%.Results show that there was an induction period at the early stage of reaction.Moreover,it is found that at temperature range of 328-358 K,the formation rate of adipic acid strongly dependents on the temperature and nitric acid concentration.The developed model is used to predict the yield of adipic acid at 359-368 K.The work in this study could provide much knowledge for industrial tubular reactor design.

Highly dispersed metal incorporated hexagonal mesoporous silicates for catalytic cyclohexanone oxidation to adipic acid

Adipic acid is a dicarboxylic acid of great industrial importance,mainly used in the production of nylon-6,6 and polyurethane.The use of nitric acid as an oxidant in the industrial production of adipic acid poses significant carbon footprint to the environment.Clean adipic acid synthesis methods using a heterogeneous catalyst with H2O2 as oxidant and water as solvent have potential advantages of low catalyst cost,easy synthesis and recovery,cleanness and environmental protection.In this work,hexagonal mesoporous silicate materials were synthesized by a sol–gel method and evaluated for cyclohexanol/cyclohexanone oxidation to adipic acid.The physical and chemical properties of Fe-HMS were characterized by XRD,HR-TEM,BET and UV–Vis.The experimental results showed that Fe-HMS materials show pore sizes ranging from 2–3 nm.W-and Mo-based polyoxometalates were also evaluated and compared to the Fe-based HMS catalysts.To improve the adipic acid yield,the influence of the transition metal as well as the effect of metal loading,reaction temperature and catalyst amount on the catalytic performances of Fe-HMS have been investigated in details.When Si/Fe atomic ratio=100,Fe-HMS catalyst shows the highest activity,with a cyclohexanone conversion of 92.3%and adipic acid selectivity of 29.4%.The reaction pathway of cyclohexanone oxidation was further proposed based on experimental data.

Scenario analysis on abating industrial process greenhouse gas emissions from adipic acid production in China

Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate greenhouse gas control roadmaps.The forecasting method of this paper is consistent with the published national inventory in terms of caliber.Based on the N_2 O abatement technical parameters of adipic acid and the production trend,this paper combines the scenario analysis and provides a measurement of comprehensive N_2 O abatement effect of the entire industry in China.Four future scenarios are assumed.The baseline scenario(BAUS) is a frozen scenario.Three emission abatement scenarios(ANAS,SNAS,and ENAS) are assumed under different strength of abatement driving parameters.The results show that China's adipic acid production process can achieve increasingly significant N_2 O emission abatement effects.Compared to the baseline scenario,by 2030,the N_2 O emission abatements of the three emission abatement scenarios can reach 207-399 kt and the emission abatement ratios can reach 32.5%-62.6%.By 2050,the N_2 O emission abatements for the three emission abatement scenarios can reach 387-540 kt and the emission abatement ratios can reach 71.4%-99.6%.

Using Adaptive Gain Scheduling LQR Method Control of Arm Driven Inverted Pendulum System Based on PIC18F4431

The arm driven inverted pendulum system is a highly nonlinear model, muhivariable and absolutely unstable dynamic system so it is very difficult to obtain exact mathematical model and balance the inverted pendulum with variable position of the ann. To solve this problem, this paper presents a mathematical model for arm driven inverted pendulum in mid-position configuration and an adaptive gain scheduling linear quadratic regulator control method for the stabilizing the inverted pendulum. The proposed controllers for arm driven inverted pendulum are simulated using MATLAB-SIMULINK and implemented on an experiment system using PIC 18F4431 mieroeontroller. The result of experiment system shows the control performance to be very good in a wide range stabilization of the arm position.

Ring-opening Copolymerization of Adipic Anhydride and Propylene Oxide Catalyzed by Yttrium Triflates

The ring-opening copolymerization of adipic anhydride with propylene oxide was carried out with yttrium triflates as a catalyst. Poly（propylene adipate） could be synthesized by controlling the copolymerization conditions. The copolymerization procedure was tracked by ^1H NMR analyses.

Synthesis and Crystal Structure of a 2-D Framework Supramolecular Complex [Cd_2(phen)_2(adip)(NO_3)_2]

A novel binucleus complex [Cd2（phen）4（adip）（NO3）2] （phen = phenanthroline, H2adip = adipic acid） has been synthesized by the reaction of phen and H2adip with cadmium（Ⅱ） salt. Elemental analysis, IR spectra and X-ray crystal structure analysis were carried out to determine the crystal structure of the title complex. The crystal belongs to triclinic, space group P1^- with a = 9.638（7）, b = 10.315（7）, c = 13.109（10） A, α = 88.305（11）, β = 69.011（11）, γ = 75.818（11）°, C27H20N5O5Cd, Mr = 606.88, Z = 2, V = 1177.2（14）A^3, Dc = 1.712 g/cm^3,μ= 0.979 mm^-1, -8≤h ≤11, -12≤k≤ 12, -10≤l≤ 15, F（000） = 610, Rint = 0.0314, R = 0.0739 and wR = 0.1922 （Ⅰ〉 2σ（Ⅰ）. The cadmium atom is seven-coordinated in a distorted pentagonal bipyramidal configuration. The complex forms a 2-D supramolecular framework by C-H…O weak interactions and π-π stacking of neighbouring phen ligands.

Study on the Synthesis and Biodegradation of Aliphatic Polyester

An aliphatic polyester, poly(hexalene adipate) (PHA) and an aliphatic copolyester, poly (hexalene adipate succinate) (PHAS) were synthesized by direct condensation of corresponding binary acid and binary alcohol in the presence of a catalyst, p-toluene sulfonic acid. The biodegradation of these polyesters were studied in the laboratory by enzyme attack and outdoor soil burial. The results show that these polyesters have good biodegradability and the copolyester PHAS, even displayed a better biodegradability than the polyester PHA. In the presence of Penicillium chrysogenum the weight loss reached 18.3% for the PHAS (film thickness 1.0 mm) and 9.1% for the PHA (film thickness 1.0 mm) after 28 days. Outdoor soil burial tests indicate that these polyesters also have good biodegradability in natural conditions. The weight loss reached 14.2% for PHAS (film thickness 0.1 mm) and 6.7% for PHA (film thickness 0.1 mm) after burying in soil for 36 days.

Thermal Behavior and Crystal Transition of Biodegradable Poly(butylenes adipate)Revealed by Two-Dimensional Correlation Spectroscopy

In the present study,thermal behavior and crystal transition of pure poly(butylene adipate)(PBA)upon heating process were investigated by FTIR spectroscopy.To gain further insight into the thermal behavior alteration and the phase transition of PBA,we performed two-dimensional(2D)correlation analysis.We found thatβ-form PBA crystal undergoes not only the melting process but also crystal transition upon the heating process.

Enzyme-Mediated Enantioselective Hydrolysis of Aliphatic Dicarboxylic Acid Diesters

The enzyme-mediated highly enantioselective hydrolysis of aliphatic dicarboxylic acid diesters has been developed. The racemic diesters were easily prepared by the coupling of racemic alcohols with dicarboxylic anhydrides followed by esterification or with dicarboxylic acids. In the cases of bis(1-phenylethyl) glutarate and bis(1-phenylethyl) adipate, the diesters which contained the dl- and meso-form diastereomers, were enantioselectively hydrolyzed by lipase from Candida antarctica (Novozym 435) in buffer at 30°C to afford the almost optically pure (R)-1-phenylethanol. On the other hand, the following chemical hydrolysis of the remaining (S, S)-diesters and (S)-monoesters gave the (S)-alcohol. Finally, both enantiomers were stoichiometrically obtained in about 100% isolated yield based on the racemic diesters. The enzymatic reaction was also applicable for the preparation of several optically active alcohols. In some cases, both the reactivities and enantioselectivities were quite different from those in the case of the corresponding simple acetates.

Comparative Heat Transfer Data for Solid-Liquid Phase Change of D-Mannitol and Adipic Acid

The goal of this work was to measure the heat transfer rates from thermofluid, Therminol 66, to two phase change materials, D-mannitol and adipic acid. It concerns the determination of heat transfer coefficients for the design of a concentrated solar energy plant requiring PCM thermal energy storage and is part of a wider set of experiments, where several PCMs were tested. An experimental installation was used with a cylindrical vessel with three tubes disposed almost horizontally (5°inclination), containing the phase change material, around which the thermal fluid flowed almost perpendicular to the tubes. The experimental installation allowed to recreate heating and cooling cycles. In order to evaluate the influence of the flow on the rate at which the heating and cooling processes took place, tests were performed at different thermofluid mass flow rates, concluding that there is no great influence, since the thermal resistance inside the tubes is much higher than on the outside. D-mannitol and adipic acid, present different phase change temperatures, 164°C for D-mannitol and 152°C for adipic acid. The average heat transfer coefficient, during the phase change process, was of 340 W/(m2K) for D-mannitol and 1320 W/(m2K) for adipic acid.

Synthesis,Crystal Structure and Characterization of a New Coordination Polymer Based on Trinuclear Mn(Ⅱ) Cluster:[Mn_3(L)_2(adip)_3]·2H_2O

The coordination polymer,[Mn3（L） 2（adip） 3]·2H2O（L = 2-（4-fluorophenyl） -1H-imidazo[4,5-f] [1,10]phenanthroline and H2adip = adipic acid） ,has been synthesized under hydro-thermal conditions and characterized by elemental analysis,IR and single-crystal X-ray diffraction. It crystallizes in triclinic,space group P1^- with a = 8.4085（11） ,b = 11.1273（14） ,c = 14.5758（18） ,α = 78.528（2） ,β = 75.425（2） ,γ = 78.143（2） °,V = 1276.0（3） A^3,Z = 1,C56H50F2Mn3N8O14,Mr = 1261.86,Dc = 1.642 g/cm^3,F（000） = 647,μ（MoKa） = 0.819 mm^-1,R = 0.0446 and wR = 0.1008. The backbones of the two types of adip dianions link the neighboring trinuclear Mn（Ⅱ） clusters to yield a two-dimensional layer structure. The large conjugated L ligands are located on both sides of the two-dimensional layers. Additionally,the O-H···O,O-H···N and N-H···O hydrogen bonds further stabilize the structure.

Study on the catalyst in the decomposition reaction for BI organic waste water to adipic acid

The influences of kinds and level of catalyst, time of decomposition reaction on the distribution of dibasic acid and apparent yield of adipic acid were researched; the acidic washing waste water （BI waste water） producing from the equipment of cyclohexane oxidation by air was as stuff, the component of products by decomposed and oxidated in different conditions were analysed. It indicated that in the presence of cobalt salt the apparent yield of adipic acid was upto 10%-12% for the total BI waste water after the concentrated BI waste water refluxed for two hours, and then oxidated by nitric acid.