Aurelia Pascariu

Solvent and catalyst-free synthesis of polyphosphates

Direct, efficient, solvent and catalyst-free synthesis of a series of polyphosphates was accomplished. The reaction involved a gas–liquid interfacial polycondensation between alkyl(aryl)phosphoric dichlorides and aromatic diols. The polyphosphates were characterized by IR, 1H NMR, inherent viscosity, thermal analysis, X-ray diffractions and molar mass. Yields in the range 75–90% and inherent viscosities in the range 0.24–0.45 dl g−1 were obtained. Polyphosphates were stable up to 170–250 °C, depending on phosphoric dichloride type. The X-ray diffraction patterns revealed that almost all the polymers were amorphous.

Organic solvent-free synthesis of phosphorus- containing polymers*

Direct, efficient, organic solvent- and catalyst-free synthesis of a series of polyphosphates was accomplished. The reaction involved a gas-liquid interfacial polycondensation between arylphosphoric dichlorides and bisphenol A. The polyphosphates were characterized by IR, 1H NMR, 31P NMR, inherent viscosity, thermal analysis, and molar mass. Yields in the range 70-90 % and inherent viscosities in the range 0.30-0.40 dl/g were obtained. The thermal stability of the polyphosphates was investigated by using thermogravimetry.

Mixed Quaternary Ammonium and Phosphonium Salts Bound to Macromolecular Supports for Removal Bacteria from Water

This paper deals with synthesis and characterization of mixed quaternary ammonium and phosphonium salts grafted on macromolecular supports by polymer-analogous trans-quaternization reactions. The degrees of functionalization with quaternary mixed ammonium and phosphonium groups are relatively high, ranging from 0.09 to 1.285 mmoles of functional groups/gram of copolymer, ensuring a sufficient concentration of active centers per unit mass of copolymer and being well suited for application as antibacterial agents.

Synthesis of Mixed Alkylphosphites and Alkylphosphates

Some mixed phosphites having two different alkyl chain were obtained as forerunners for mixed phosphates Mixed dialkyl phosphates were obtained in good yields (40-80%) by phase transfer catalysis in liquid-liquid sistem, starting from different dialkyl phosphites and aliphatic alcohols. The reaction conditions were optimized in order to obtain good yields in phosphites and phosphates respectively. Compounds were analyzed by IR, P 31 -NMR.

Wittig and Wittig-Horner reactions under phase transfer catalysis conditions

Wittig and Wittig-Horner reactions are favorite tools in preparative organic chemistry. These olefination methods enjoy widespread and recognition because of their simplicity, convenience, and effciency. Phase transfer catalysis (PTC) is a very important method in synthetic organic chemistry having many advantages over conventional, homogenous reaction procedures. In this paper, we attempt to summarize the aspects concerning Wittig and Wittig-Horner reactions that take place under phase transfer catalysis conditions.

Synthesis of Polyphosphates Related to Biopolymers

Polyphosphates were synthesized by base promoted liquid-vapor polycondensation of cyclohexylphosphoric dichloride with bisphenol A. The effects of temperature, reaction time, base concentration and molar ratio of reagents on yield, inherent viscosity and molecular weight of the obtained polymer were studied. A second order, central composite, rotatable experimental design was used to find domain experimental field for optimal yields and high inherent viscosities.

The Influence of the Molar Ratio SPCl 3 : Phenol on the Formation of the Disubstituted Secondary Products in the Liquid-Liquid PTC Synthesis of Arylthiophosphoric Acid Dichlorides

The reason for this study is that the arylthiophosphoric acid dichlorides are used as reactants for consecutive reactions without purification and the content of the secondary product can influence those. The molar ratio is not critical in the case of phenol, but for the substituted phenols it represents one of the most important factors that controls the content of the secondary product formed in the reaction. Generally, the increase of the value of molar ratio, reduce the content in diarylthiophosphoric acid chloride, but this value is less than nonPTC synthetic routes.

Reduction of Cr(VI) Using Polyaniline–Polystirene-Divinyl Benzene Gels

Wastewaters generated by electroplating, Industry of Pigments, Tannins, etc. contain Cr(VI).The removal of Cr(VI)from wastewaters is necessary due to its toxicity; the admissible concentration being 10 ppm.This work studies quantitatively and qualitatively the possibility of treating waste waters that have a concentration of 0.1 g/l Cr(VI), by using DVB gels coated with Pani films.The Pani films were applied on the DVBs surface both by polymerization of aniline in acid medium, using ammonium peroxodisulphate as the oxidizing agent and by treating the DVB gels with Pani solutions in N,N-dimethylformamide.During reaction, the reduction rate of Cr(VI)decreases because the Pani films are degrading. This degradation is generated by over-oxidation, phenomenon that leads to a series of secondary hydrolysable products.