Water-dispersible non-aqueous emulsions stabilized by a poly(butadiene)-b-poly(2-vinylpyridine) block copolymer

Submicron non-aqueous emulsions, of interest for biomedical and cosmetic formulations, were developed for the system comprising poly(ethylene glycol) (PEG) 400 and Miglyol 812, an enzymatic degradable liquid glycerine ester. These emulsions, with PEG 400 as continuous phase and Miglyol 812 droplets, in the size range of 200 nm, were stabilized by a poly(butadiene)-b-poly(2-vinylpyridine) (PBut-b-P2VP) block copolymer with a composition close to 50/50 wt%. The droplet size, stability and the rheological characteristics were examined as a function of the copolymer concentration. An original aspect of these anhydrous emulsions, with a water miscible continuous phase, is their water dispersibility without additional surfactant. In fact, the initial anhydrous emulsion is sterically stabilized and after water addition at low pH, the protonated P2VP sequence of the copolymer provides the electro-steric stabilization. This oil-in-water emulsion is characterized by sub micron sized Miglyol 812 droplets in an aqueous phase of PEG 400 and water at pH 1.     

Synthesis of N-substituted-2-aminobenzothiazoles using nano copper oxide as a recyclable catalyst under ligand-free conditions in reusable PEG-400 medium

A simple and practical method for the synthesis of N-substituted-2-aminobenzothiazoles via a crosscoupling reaction of 2-iodo anilines with isothiocyanates is envisaged using nano copper oxide as a recyclable catalyst and Cs2CO3as a base in PEG-400,as a bio-degradable,reusable,inexpensive and nontoxic reaction medium,under ligand-free conditions.The present tandem process underlines environmental acceptability to access a wide range of N-substituted-2-aminobenzothiazoles in good to excellent yields.     

Volume and heat capacity of model non-aqueous self-assembly systems

Blends of immiscible polymers are often stabilized by block copolymers which can form non-aqueous micelles and microemulsions in the liquid polymers. The phase diagrans, apparent volumes and apparent heat capacities of model non-aqueous binary and ternary systems were studied in order to investigate the conditions under which such self-assembly systems could form. 1,2-Hexanediol, which can cosolubilize hexane and ethyleneglycol, forms inverse micelles in hexane and weak microaggregates in ethyleneglycol. Genapol X-060, a commercial alcoholic surfactant containing on the average an aliphatic chain of 13 carbons and 6 oxyethylenes (C₁₃E₆), forms microaggregates in poly(ethyleneglycol) 400. These self-assembly systems are strengthen in the presence of a third component which has an affinity for the inner phase.Presented at the Symposium, 76^th CSC Congress, Sherbrooke, Quebec, May 30–June 3, 1993, honoring Professor Donald Patterson on the occasion of his 65^th birthday.     

Synthesis of (Z)-organylthioenynes using KF/Al2O3/solvent as recyclable system

PEG-400 and glycerol were successfully used as recyclable solvents for the synthesis of several organylthioenynes in good to excellent yields and high selectivity using solid supported catalyst (KF/Al₂O₃). This easy, general and improved method furnishes the corresponding alkenyl sulfides preferentially with Z configuration. The catalytic system and the glycerol or PEG-400 can be reused up to three times without previous treatment with comparable activity.     

二氧化锰纳米棒的固相合成与表征

上世纪90年代以来,纳米科技向化学电源领域渗透,科技工作者开始研发纳米级MnO2电极材料,主要包括MnO2纳米粉体的制备[1-8]和将其作为碱锰电池正极材料[1-3]、高能量密度锂电池正极材料以及超级电容器电极材料的性能研究[4-8].     

Transformation of Oximes and Alcohols to Carbonyl Compounds Using Amberlite IRA-400 Supported Chromic Acid in the Presence of Zirconium Tetrachloride

A wide variety of oximes and alcohols were efficiently converted to their corresponding aldehydes and ketones in good to excellent yields using amberlite IRA-400 supported chromic acid in the presence of zirconium tetrachloride in refluxing acetonitrile-H2O. Selective oxidation of oximes and alcohols in the presence of other functional groups such as acetal, hydrazone, aldehyde, ether and alkene can be considered as a noteworthy advantage of this method. A wide variety of oximes and alcohols were efficiently converted to their corresponding aldehydes and ketones in good to excellent yields using amberlite IRA-400 supported chromic acid in the presence of zirconium tetrachloride in refluxing acetonitrile-H2O. Selective oxidation of oximes and alcohols in the presence of other functional groups such as acetal, hydrazone, aldehyde, ether and alkene can be considered as a noteworthy advantage of this method.     

An Efficient,Basic Resin-Mediated,One-Pot Synthesis of Dithiocarbazates Through Alcoholic Tosylates

A quick and efficient, one-pot synthesis of dithiocarbazates was accomplished in high yields by the reaction of various alcoholic tosylates of primary, secondary, and tertiary alcohols, with substituted hydrazines using an Amberlite IRA 400 (basic resin)/CS ₂ system. The reaction conditions are mild with simpler work-up procedures than previously reported methods.     

PEG-400 mediated an efficient eco-friendly synthesis of new isoxazolyl pyrido[2,3-d]pyrimidines and their anti-inflammatory and analgesic activity

Abstract

Polyethylene glycol-400 (PEG-400) has been developed as an efficient and eco-friendly reaction medium for the synthesis of new isoxazolyl pyrido[2,3-d]pyrimidine derivatives 11 from isoxazolyl cyanoacetamide synthon 7. Compound 7 was employed with various aromatic aldehydes 8 and malononitrile 9 in the presence of triethylamine (Et₃N) to afford the corresponding (E)-6-amino-1-(3-methyl-5-styrylisoxazol-4-yl)-2-oxo-4-phenyl-1,2-dihydro- pyridine-3,5-dicarbonitrile 10 at room temperature by using PEG-400 as a solvent medium as well as catalyst. The intermediate 10 on treatment with thiourea in the presence of PEG-400 at 90?°C to give the target compounds isoxazolyl pyrido[2,3-d]pyrimidines 11 in good to excellent yields. The newly synthesized compounds 10 and 11 were characterized by IR, ¹H NMR, ¹³C NMR, and HRMS analysis. The target compounds 11a-x was screened for their anti-inflammatory and analgesic activities. Among the tested compounds, the compounds 11s, 11t, 11u, 11v, 11w, and 11x showed significant anti-inflammatory and potent analgesic activities as that of reference drugs. The advantages of this protocol are operational simplicity, catalyst free, environmental safety, wide substrate scope, good yields, and PEG-400 can be recovered and reused. Most significant of all, this protocol is green.     

Multiscale Spectral Analysis on Lysozyme Aqueous Solutions in the Presence of PolyEthyleneGlycol

Infrared spectroscopy measurements were performed on Lysozyme aqueous solutions also in the presence of PolyEthylene Glycol (PEG 400) as a function of an increasing temperature from T = 27 °C to 90 °C, and, successively in sequence, by decreasing temperatures from T = 90 °C to 27 °C. Data were analyzed by evaluating the spectral difference with respect to the initial spectrum collected at 27 °C. This procedure allows to quantitatively evaluate the thermal restraint related to the thermal scan from T = 27 °C to 90 °C, as well as to introduce a spectral resilience concerning the entire increasing and decreasing thermal paths which allow to highlight the bioprotectant effectiveness of low molecular weight PEG. In particular, the main purpose of the present work is to highlight the effects of a thermal treatment on a mixture of Lysozyme/water and of Lysozyme/water/PEG 400 during an increasing temperature scan, and then after a successive decreasing temperature scan, in order to highlight the bioprotectant role of PEG 400. On that score, an evaluation of the spectral distances of the registered spectra as a function of increasing and decreasing temperatures has been performed and analyzed.     

Efficient Copper(I)‐Catalyzed S‐Arylation of KSCN with Aryl Halides in PEG‐400

A simple and efficient protocol for CuI‐catalyzed C? S bond formation of aryl halides with KSCN to symmetrical diaryl sulfides was reported in PEG‐400 without any other additives. A variety of aryl halides were converted to the corresponding diaryl sulfides in good to excellent yields. The present procedure tolerated a variety of functional groups and the steric hindrance of ortho‐substituents on aryl halides did not affect the outcome.