Liquid–liquid equilibria of aromatics removal from middle distillate using NMP

We investigated the removal of aromatics from a typical Kuwait middle distillate using liquid–liquid extraction. A multicomponent system; dodecane + hexadecane + 1,3,5-trimethyl benzene (mesitylene) + butylbenzene; was used to represent the middle distillate mixture. N-methyl-2-pyrrolidone (NMP) was used as a solvent. The liquid–liquid equilibria (LLE) of the mixture was studied over a temperature range of 293–323 K and at different solvent to feed ratios (1.35–1.97). The selectivity and distribution coefficient of the solvent were correlated successfully using the universal quasi-chemical (UNIQUAC) model for the pseudo-ternary system (paraffins (1) + aromatics (2) + NMP (3)) at the studied temperature range. The UNIQUAC model fit the experimental data with an average percentage root mean square deviation (rmds) of 0.2980%.     

Photodissociation Rate Constants of New Light Sensitive Alkoxyamines

The photochemical properties of two new photocleavable alkoxyamines bearing a benzophenone‐derived chromophore were studied by electron spin resonance (ESR). The C O bond cleavage has been demonstrated and the photolysis rate constants (k_d) determined over a large range of light intensity through the monitoring of the nitroxide concentration in aerated conditions. The obtained kinetic data highlight for the first time the linear dependence of k_d on the light intensity for alkoxyamines: this should be a driving factor for nitroxide mediated radical photopolymerization (NMP²).

     

Alkoxyamines of Stable Aromatic Nitroxides: N?O vs. C?O Bond Homolysis

A series of stable 2,2‐disubstituted 3‐(phenylimino)indol‐1‐oxyls, the alkoxyamines 3 , were prepared, characterized, and tested as possible candidates in controlled radical polymerization (CRP). The sturctures of 3d and 10 were additionally solved by X‐ray diffraction. The lability of the N? O(C) and (N)O? C bonds of compounds 3 were compared, and the possibility of N? O vs. O? C bond cleavage was evaluated by thermal degradation, ESR spin trapping, MS experiments, and DFT calculations. Alkoxyamines with a primary‐ or secondary‐alkyl group bound to the O‐atom of the nitroxide function (hexyl and i‐Pr) mainly underwent (undesired) N? O bond homolysis. When the O‐alkyl radical was a tertiary or a benzyl group (crotonyl or styryl), O? C bond cleavage occurred as the main process, thus suggesting a possible use of these compounds in CRP processes.     

Detection of carbohydrates using new labeling reagent 1-(2-naphthyl)-3-methyl-5-pyrazolone by capillary zone electrophoresis with absorbance (UV)

Surface plasmon resonance (SPR) was used to screen the interaction between a variety of affinity ligands and hemagglutinin (HA) from human influenza virus, with the aim of identifying low affinity ligands useful for the development of a rapid bioanalytical sensor. Three sialic acid-based structures and four lectins were evaluated as sensor ligands. The sialic acid-based ligands included a natural sialic acid-containing glycoprotein, human alpha1-acid glycoprotein (alpha1-AGP), and two synthetic 6'-sialyllactose-conjugates, with varying degree of substitution. The interaction of HA with the four lectin-based ligands, concanavalin A (Con A), wheat germ agglutinin (WGA), Maackia amurensis lectin (MAL), and Sambucus nigra agglutinin (SNA), showed a wide variation of affinity strengths. Affinity and kinetics data were estimated. Strong affinities were observed for Con A, WGA, alpha1-AGP, and a 6'-sialyllactose-conjugate with a high substitution degree, and low affinities were observed for MAL and a 6'-sialyllactose-conjugate with low substitution. The main objective, to identify a low affinity ligand which could be used for on-line monitoring and product quantification, was met by a 6'-sialyllactose-ovalbumin conjugate that had 0.6 mol ligand per mol carrier protein. The apparent affinity of this ligand was estimated to be 1.5+/-0.03 microM (K(D)) on the SPR surface. Vaccine process samples containing HA were analyzed in the range 10-100 microg HA mL(-1) and correlated with single-radial immunodiffusion. The coefficient of variation on the same chip was between 0.010 and 0.091.     

光调控的活性自由基聚合的研究新进展

从引发和催化两个方面概述了光辐照在活性自由基聚合(LRP)中的应用,从机理上详细地分析了光辐照对氮氧调控自由基聚合(NMP)、原子转移自由基聚合(ATRP)、可逆加成-断裂链转移自由基聚合(RAFT)以及有机钴催化的可控自由基聚合反应(CMRP)的影响。与传统自由基聚合相比,光调控的活性自由基聚合方法可在温和的条件下生成自由基,能够克服传统LRP的一些缺陷,如降低催化反应活化能、提高聚合物末端官能度等。同时,本文对光调控反应的进一步应用以及新方法的产生也进行了展望。     

Genesis of the CSIRO polymer group and the discovery and significance of nitroxide‐mediated living radical polymerization

The background to the formation of the Commonwealth Scientific and Industrial Research Organization (CSIRO) polymer group is discussed. In particular, the challenges of working with high‐conversion polymerization, as found in commercial systems, and the need to explain variations in polymer properties led to important advances in the theory of radical polymerization and control over both the initiation and termination steps. Studies on the fate of the macromonomer, formed in termination by disproportionation, led to an early form of addition/fragmentation now known as reversible addition–fragmentation chain transfer, whereas detailed studies on initiation pathways using nitroxide trapping led to nitroxide‐mediated living radical polymerization. These studies contributed to the renaissance in free‐radical polymerization studies. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5748–5764, 2005     

Theoretical Study of the Structural Stability,Chemical Reactivity,and Protein Interaction for NMP Compounds as Modulators of the Endocannabinoid System

The cannabinoid receptors (CB1/CB2) and the T-type calcium channels are involved in disorders associated with both physiological pain and depressive behaviors. Valuable pharmacological species carbazole derivatives such as the NMP-4, NMP-7, and NMP-181 (Neuro Molecular Production) regulate both biological entities. In this work, DFT calculations were performed to characterize theoretically their structural and chemical reactivity properties using the BP86/cc-pVTZ level of theory. The molecular orbital contributions and the chemical reactivity analysis reveal that a major participation of the carbazole group is in the donor-acceptor interactions of the NMP compounds. The DFT analysis on the NMP compounds provides insights into the relevant functional groups involved during the ligand-receptor interactions. Molecular docking analysis is used to reveal possible sites of interaction of the NMP compounds with the Ca_v3.2 calcium channel. The interaction energy values and reported experimental evidence indicate that the site denominated as “Pore-blocking”, which is formed mainly by hydrophobic residues and the T586 residue, is a probable binding site for the NMP compounds.     

NMP-mediated chlorination of aliphatic alcohols with aryl sulfonyl chloride for the synthesis of alkyl chlorides

NMP-mediated chlorination of aliphatic alcohols has been developed for the synthesis of alkyl chlorides. This facile, efficient and practical approach used simple and readily available aryl sulfonyl chlorides as the chlorination reagent for the construction of C–Cl bond in good to excellent yields with mild conditions and broad substrate scope.     

Effect of a Novel Polymeric Coupling Agent on the Water Uptake Property and Warp Stability of Poly(vinyl chloride)/Bamboo Flour Composite

Water uptake property and warp stability of poly(vinyl chloride) (PVC)/bamboo flour composite were investigated employing a novel polymeric coupling agent, poly(styrene-co-maleic anhydride)-block-poly(styrene-co-acrylonitrile) {P[(SMA)-b-(SAN)]}. P[(SMA)-b-(SAN)] was synthesized through controlled/'living' radical polymerization (CRP) technique in an one-pot reaction and incorporated into the composite to improve the interfacial adhesion between PVC and bamboo flour. The structure of P[(SMA)-b-(SAN)] was confirmed by ¹H-NMR, FT-IR and GPC. PVC/bamboo flour composite sheets were then prepared from a single screw extruder and two-roll mill in the presence of P[(SMA)-b-(SAN)] coupling agent. As the content of the coupling agent increased, improved interfacial bonding between PVC and bamboo flour filler was observed. Water uptake property and warp stability were also improved in the presence of the coupling agent. These results suggest that the block copolymer successfully acted as a coupling agent in PVC/bamboo flour composites.