一种活性磷酸酯的分子内亲核取代反应动力学研究

合成和表征了大环过渡金属配合物NiL(L:高氯酸-5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂环十四烷)。配合物NiL与表面活性剂组成的金属胶束作为模拟水解金属酶用于催化BNPP水解。提出了BNPP催化水解的机理;建立了用于计算动力学常数的动力学模型;计算了相关的动力学和热力学常数。结果表明,这种金属胶束表现出较高的催化活性;BNPP催化水解反应是分子内亲核取代反应;所提出的机理和建立的动力学模型是合理的。     

沥青质分散剂对沥青质的稳定及缔合的影响

采用紫外－可见光谱法研究了沥青质分散剂对甲苯－正庚烷－沥青质体系中沥青质的稳定作用,通过黏度法考察了沥青质分散剂对沥青质溶液中胶束缔合度的影响。结果表明,十二醇（DAL）、十二烷基苯磺酸（DBSA）、十二烷基苯酚（DP）对沥青质都有一定的稳定作用。三种沥青质分散剂的稳定作用顺序为DBSA>DP>DAL。DAL、DP及DBSA浓度较低时（1%）对沥青质甲苯溶液黏度的影响规律相似,推迟了黏度迅速增加的拐点,即可以抑制沥青质胶束的缔合。DBSA浓度较大时,沥青质胶束没有明显的聚并,同时使得沥青质溶液的相对黏度增加明显。三种沥青质分散剂都能显著降低胶束的聚集数;三种沥青质分散剂抑制沥青质胶团聚并强弱顺序为：DBSA>DP>DAL。这与其头部官能团的酸性顺序一致。     

Hyperbranched polymers as a novel class of pigment dispersants

Hyperbranched polymers form a novel class of materials that are employed as components of resin formulations. They are appreciated for their low intrinsic viscosities, which is ascribed to their spherical shape. It was envisaged to devise pigment dispersants with hyperbranched moieties as structural elements. Commercially available hyperbranched polymers with polyester, polyesteramide and polyethylene imine backbones were chemically modified to develop a range of disperants with core- and shell-type pigment anchoring mechanisms. Both the shell- and core-type anchoring principles generally can be used for pigment dispersion and stabilisation at a low viscosity level.     

Synthesis of comb‐like dispersants and a study on the effect of dispersant architecture and carbon black dispersion

Comb dispersants suitable for stabilization of carbonaceous deposits found in automotive lubricating oils were derived from the copolymerization of vinyl‐ether terminated polyisobutylene (VE‐PIB) macromonomers with maleic anhydride (MAH). The rate and degree of copolymerization of VE‐PIB with MAH was greatly influenced by the molecular weight of the VE‐PIB. Longer PIB tails imposed greater hindrance of the chain end resulting in slower propagation and lower degrees of copolymerization for PIB‐alt‐MAH copolymers. Functionalization of PIB‐alt‐MAH with a polyamine proceeded smoothly at elevated temperatures as evidenced by disappearance of anhydride stretches via Fourier transform infrared spectroscopy. Analogous linear and grafted dispersants were prepared to investigate the influence of architecture on the physical properties of the dispersants. Characterization of the intermediates and final dispersants was conducted by nuclear magnetic resonance, gel permeation chromatography, thermogravimetric analysis, and ultraviolet–visible. Using Langmuir adsorption studies and carbon black as a substitute for carbonaceous deposits, it was found that comb and grafted dispersants exhibit greater affinities for adsorption but decreased packing efficiencies in comparison to linear dispersants. Rheological studies investigating viscosity as a function of loading for dispersant/oil mixtures with carbon black present a similar finding. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1682–1696     

一定条件下硝酸酯炸药与聚氨酯胶的相互作用研究

用气相质谱(GC-MS)、FTIR对在100℃下处理数十小时后的硝酸酯炸药、聚氨酯胶及二者隔离体系和接触体系的气相组分、凝聚相进行了表征。结果表明:两者直接接触后,彼此之间发生的变化主要由硝酸酯炸药发生分解产生的NO2促使聚氨酯胶的降解并加速自身的分解,聚氨酯胶的降解产物又进一步催化硝酸酯炸药的分解;两者间接接触后,各自释出的气氛对彼此的结构没有影响。     

Preparation of poly(phosphate ester)s having bisphenol moieties as mesogenic units in the main chain

Poly(phosphate ester)s, PPE 1a–d , were synthesized from polycondensation of methyl phosphorodichloridate (MPDC) with various bisphenols such as 4,4′-biphenol 1a , 4,4′-dihydroxyphenylether 1b , bis(4-hydroxyphenyl)methane 1c , and 3,3′-dimethyl-4,4′-dihy-droxybiphenyl 1d . PPE 2a–d with hexamethylene spacers were also obtained from poly-condensation of MPDC with 4,4′-bis(6-hydroxyhexyloxy)biphenyl 2a , 4,4′-di(6-hydroxyhexyloxy)phenyl ether 2b , bis[4-(6-hydroxyhexyloxy)phenyl]methane 2c , and 3,3′-dimethyl 4,4′-di(6-hydroxyhexyloxy)biphenyl 2d . The degree of crystallinity of PPE 1a–1d without hexamethylene spacer was 3.3–17.6%, whereas PPE 2a and PPE 2b which exhibit mesomorphic behavior were 20.1 and 18.6%, respectively. PPE 2a and PPE 2b show the mesophase at 139.6–195.5°C and 42.4–66.3°C, respectively. PPE 2c and PPE 2d were obtained as rubbery. From pyrolysis of PPE in air the temperature corresponding to 5% weight loss was found to be 322–408°C and 284–291°C for PPE 1 and PPE 2 , respectively. It was also found that PPE 2a was enzymatically degraded by phospholipase C. © 1994 John Wiley & Sons, Inc.     

不同水煤浆分散剂与煤之间的相互作用规律研究: Ⅹ 分散剂在煤粒表面上的吸附作用特征

研究了6种水煤浆分散剂在14种不同变质程度煤上的吸附作用特征。结果表明，多数分散剂在煤粒表面达到单层饱和吸附后，又形成多层吸附，单层饱和吸附量与煤的变质程度、比表面积以及分散剂的性质有关。在相同粒度分布下，煤的变质程度越低，表面含氧亲水官能团的比例越高，孔隙率越高，比表面积越大，这对增大吸附量有利。煤的变质程度越高，其表面疏水区面积的比例越高，分散剂通过疏水基团紧密吸附在煤表面的比例越大，这对增加高阶煤的吸附量有利。对不同煤，是变质程度还是比表面积为吸附分散剂的主控因素，主要依赖于分散剂的结构与性质。对同种煤，疏水与亲水基团呈线型分立分布的分散剂，吸附量明显高；而疏水与亲水基团呈线型间隔分布的分散剂，吸附量明显小。     

Adsorption of surfactants onto acrylic ester resins with different pore size distribution

In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to inves-tigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS), sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 38# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation indicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption proc-ess.     

新型金属胶束模拟酶对羧酸酯与磷酸酯的催化水解

报道了三种新的含醇羟基、胺基或咪唑基长链配体与铜锌离子构成的金属胶束对几种羧酸酯与磷酸酯底物催化水解动力学。结果表明,设计的金属胶束N-十四烷基-2-(N-2'-羟乙基氨基甲基)咪唑锌铜(2a,2b)在共胶束CTAB(溴化十六烷基三甲铵)存在下,对强配位羧酸酯对硝基苯酚-2-吡啶甲酸酯具有很强的催化水解能力,对磷酸酯对硫磷具有很高的反应性,2a,2b的醇羟基参与了对弱配位底物羧酸酯及磷酸酯的进攻,对不同电荷性质的羧酸酯底物具有较强的静电选择性。     

In situ sol-gel preparation of porous alumina monoliths for chromatographic separations of adenosine phosphates

A method enabling the in situ preparation of porous alumina monoliths within 100 μm i.d. fused silica capillaries has been developed. These monoliths were prepared using the sol-gel process from a mixture consisting of an inorganic aluminum salt, a porogen, an epoxide, and a solvent. We investigated the effects of varying the preparation conditions on the physical characteristics of the monoliths with respect to their potential application in chromatographic separations. The best columns were obtained from a mixture of aluminum chloride hexahydrate, N,N-dimethylformamide, water, ethanol and propylene oxide. Adenosine phosphates were then separated in the optimized column with retention increasing according to number of phosphate functionalities.     

Two‐dimensional liquid chromatography with active solvent modulation for studying monomer incorporation in copolymer dispersants

A pseudo‐comprehensive two‐dimensional liquid chromatography approach with size exclusion chromatography in the first dimension and gradient reversed‐phase liquid chromatography in the second dimension was successfully developed for the characterization of vinyl acetate/acrylic acid copolymers and vinyl acetate/itaconic acid/acrylic acid terpolymers. Active solvent modulation was exploited to prevent the polymer breakthrough in the second dimension separation caused by the strong solvent used in the first dimension. The conditions of the active solvent modulation valve were optimized to achieve sufficient on‐line dilution and to completely prevent polymer breakthrough without adding excessive time to the modulation cycle. Using this approach, copolymers made with different monomer ratios and processes were studied. Heterogeneous composition distribution due to insufficient monomer incorporation was detected in some of the copolymer samples. We demonstrated that with active solvent modulation, the two‐dimensional liquid chromatography approach is no longer limited to water‐soluble polymers and can be used for a broader range of polymers and copolymers.     

O,O′-二(2-氯乙基)-O″-[2-二(2-氯乙氧基)磷酰丙基]磷酸酯的合成

报道了以三氯化磷、乙二醇、环氧乙烷、丙酮和氯气等原料合成新型阻燃剂O,O′-二(2-氯乙基)-O″-[2-二(2-氯乙氧基)磷酰丙基]磷酸酯的方法.探讨了反应温度、催化剂以及反应时间等条件对各步反应的影响,产品总收率92%以上.采用元素分析、红外光谱和核磁共振等表征了合成化合物的结构.     

Synthesis of TRITON™ X-based phosphate ester surfactants and their self-charring behavior

This paper describes the synthesis and characterization of a series of TRITON™ X-based surfactants with a predominantly alkyl phenol ethoxylate (APE) backbone and a phosphate ester chain end. Four phosphate-terminated TRITON™ X (or APE) derivatives (OPE2-OPO(OH)₂, OPE5-OPO(OH)₂, OPE10-OPO(OH)₂, and NPE10-OPO(OH)₂) were prepared from commercially available octyl phenol ethoxylate (OPE) of different oxyethylene units (n = 2, 5 and 10), nonyl phenol ethoxylate (NPE) of 10 oxyethylene units and phosphorous pentoxide via a simple condensation reaction. Depending on their composition and chain length of oxyethylene units used in the reaction, the surfactants show different self-charring behaviors. The phosphate-terminated TRITON™ X of the lowest number of oxyethylene units (i.e. OPE2-OPO(OH)₂) gives the largest amount of char (up to 23 wt%) at 600 °C under air condition. The carboxylic acid-terminated TRITON™ X derivatives (i.e. OPE-COOH) were also tested for comparison.     

Accelerated polymorphic transformations of alumina

In binary systems MeO/Al₂O₃ (Me=Mg, Zn, Cu), the accelerated polymorphic transformation of alumina to α-Al₂O₃ was observed in the presence of Cu²⁺. The phenomenon is explained as catalytic, considering the Cu²⁺ electron configuration and Jahn-Teller effect.     

Synthesis and textural evolution of alumina particles with mesoporous structures

Alumina particles with mesostructures were synthesized through a chemical precipitation method by using different inorganic aluminum salts followed by a heterogeneous azeotropic distillation and calcination process. The obtained mesoporous γ-alumina particles were systematically characterized by the X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption measurement. Effects of the aluminum salt counter anion, pH value and the azeotropic distillation process on the structural or textural evolution of alumina particles were investigated. It is found that Cl⁻ in the reaction solution can restrain the textural evolution of the resultant precipitates into two-dimensional crystallized pseudoboehmite lamellae during the heterogeneous azeotropic distillation, and then transformed into γ-Al₂O₃ particles with mesostructures after further calcination at 1173 K, whereas coexisting SO₄²⁻ can promote above morphology evolution and then transformed into γ-Al₂O₃ nanofibers after calcination at 1173 K. Moreover nearly all materials retain relatively high specific surface areas larger than 100 m² g⁻¹ even after calcinations at 1173 K.     

Adsorption of phosphate from wastewater by a ZnO-ZnAl hydrotalcite

ABSTRACT

A ZnO-ZnAl hydrotalcite (ZZA) was prepared by a new centrifugal method, and its micromorphology was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. The adsorption by ZZA of phosphate in a simulated wastewater was studied in detail. The effects of a variety of factors, including pH, coexisting ions, adsorption time, ZZA dosage, and adsorption temperature, on the phosphate adsorption were evaluated. The reaction of ZZA adsorbing phosphate in the simulated wastewater may be an endothermic reaction. The adsorption process is more in line with the Langmuir model equation, indicating that it may be homogeneous surface monolayer chemisorption. By studying the thermodynamic index of ZZA adsorbing phosphate in simulated wastewater, it was suggested that the adsorption is a spontaneous, endothermic, and entropy-increasing process. For moderate and low level of phosphate amount wastewater, the emission requirements can be met.     

Synthesis and cytotoxicity evaluation of a novel justicidin G analogue and its phosphate ester

The novel justicidin G analogue 13 and its phosphate ester 15 were synthesized as potential anticancer agents in several steps starting from commercially available methyl gallate and veratraldehyde. The cytotoxicity of the intermediates was tested against HCT-8, BEL-7402, KETR3, HELA, BGC-823, KB and MCF-7 cell lines by the MTT test, and compound 15 exhibited significant cytotoxicity in HELA and KB cell lines.     

Synthesis and properties of alumina aerogels

The synthesis of alumina aerogels has been carried out by hydrolysis of aluminium isopropylate as an aerogel precursor dissolved in isopropanol or methanol, followed by gelation of the sols obtained and drying under supercritical conditions and calcination. The influence of two main preparation parameters, precursor concentration and reagents (water to aluminium isopropylate) mole ratio, on the physicochemical properties of aerogels was investigated.     

Role of carbonate-carboxylate species during alumina coking

The role of carbonate-carboxylate species on alumina surface has been studied during alumina coking. The species are intermediates poisoning the active sites. Little O₂ added to the hydrocarbon feedstock causes further oxidation of the species and promotion of the active sites.     

Effect of alumina in multicomponent bismuth phosphate catalyst supported on silica-alumina for propylene ammoxidation reaction

The effect of compositions of silica-alumina support on multicomponent bismuth phosphate catalyst (MBP) was investigated for the propylene ammoxidation. It is appears that small amounts of Al₂O₃ cause retardation of the ammoxidation reaction, which would be due to activation of the selective oxidation pathway. It is understood from such results that the catalytic action of the MBP is essentially different with that of the multicomponent bismuth molybdate catalyst (MBM), which is generally used as propylene ammoxidation catalyst. This revised version was published online in June 2006 with corrections to the Cover Date.