Amino Ethers of Ortho-Phosphoric Acid as Extragents for Ethanol Dehydration

Amino ethers of ortho-phosphoric acid prepared using triethanolamine; ortho-phosphoric acid; polyoxyethylene glycol, diethylene glycol, triethylene glycol and glycerol (AEPA-DEG/TEG/Gl) were investigated as extractants for the separation of aqueous ethanol solutions by extractive distillation. Using the method of open evaporation, the influence of the molecular structure of AEPA-DEG/TEG/Gl on the conditions of vapor–liquid equilibrium in ethanol–water solutions was studied. It has been shown that the addition of AEPA-DEG/TEG/Gl removes the azeotropic point. At the same time, the observed effect turned out to be significantly higher in comparison with the use of pure glycerol or glycols for these purposes. The UNIFAC model was used to calculate the activity coefficients in a three-component ethanol–water–AEPA-DEG/TEG/Gl mixture. Within the framework of this model, a division of AEPA-DEG/TEG/Gl molecules into group components is proposed. Previously unknown parameters of the groups PO–CH, PO–CH2, PO–OCH2, PO–NHCH2, PO–OH, and PO–H2O were determined from our own and published experimental data. The concentration dependences of the density and dynamic viscosity of AEPA-Gl aqueous solutions have been experimentally measured. Experimental studies of the extractive distillation of ethanol–water using AEPA-Gl as an extractant have been carried out in a column with bubble cap plates and a packing, and its high efficiency has been established.

Organophosphorus Polyurethane Ionomers as Water Vapor Permeable and Pervaporation Membranes

Organophosphorus polyurethane ionomers (AEPA-PU) based on aminoethers of ortho-phosphoric acid (AEPA) were obtained and studied as pervaporation membrane materials for separating isopropanol/water mixtures. The regularities of the change in the water vapor permeability of AEPA-PU were also investigated. It has been established that an increase of solute content in the composition of the urethane-forming system and the content of ionogenic groups in AEPA leads to a noticeable increase in the vapor permeability of the resulting film materials. An increase in water vapor permeability values is accompanied by a significant increase in the pervaporation characteristics of AEPU-PU. It was shown that the conditions promoting clustering of phosphate anions cause an increase in the values of the vapor permeability coefficient of AEPA-PU obtained using polyoxypropylene glycol. However, the hydrophobicity of the polypropylene glycol surrounding the clusters makes it difficult for water to move through the polymer matrix. Due to the hydrophilicity of polyoxyethylene glycol, the highest values of water vapor permeability and pervaporation characteristics are achieved for AEPA-PU synthesized using PEG.

Amphiphilic silica derivatives associated with oligomeric medium in octamethylcyclotetrasiloxane polymerization

The amphiphilic derivatives of silica associated with oligomeric medium have been studied as modifiers of the catalyst for the octamethylcyclotetrasiloxane polymerization of anionic nature. The effect of the modifiers structure on the polymerization time of the obtained polydimethylsiloxanes was investigated. It was found that the modifier, like the initial polyoxyethylene glycol, exhibits the properties of promoters for the catalytic polymerization of octamethylcyclotetrasiloxane by the anionic mechanism. To establish the role of amphiphilic silica derivatives in the occurrence of intermolecular interactions in polydimethylsiloxanes that were obtained with them, the regularities of changes in the reduced viscosity of the obtained modified polydimethylsiloxanes were analyzed. It has been established that the reduced viscosity of polydimethylsiloxanes increases with an increase of the modifier amphiphilicity. This is due to the occurrence of intermolecular interactions because the specific interaction of amphiphilic silica derivatives with polydimethylsiloxane macromolecules. When using amphiphilic derivatives of silica as a modifier of the resulting polydimethylsiloxane to a content of 6 wt% hydrophobic fragment in their composition, modification of polydimethylsiloxanes does not affect their rheological characteristics. This is due to the presence of polyoxyethylene branches in the composition of the modifier, which creates a cavity for the trapping of K+ ions, as in the crown ether, they perform only a catalytic function, which leads to an increase in the rate of the process. However, starting from 10 % wt the content of the hydrophobic component in the composition of the modifier, the reduced viscosity of the obtained polydimethylsiloxane increases due to the occurrence of intermolecular interactions between the modifier and the obtained polydimethylsiloxane. It was noted that polydimethylsiloxane obtained using only polyoxyethylene glycol as a modifier exhibits viscosity characteristics lower than polydimethylsiloxane obtained by the anionic mechanism without using any modifiers.

Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA.