Polyurethane ionomers based on amino ethers of ortho-phosphoric acid

Self-Organization of Polyurethane Ionomers Based on Organophosphorus-Branched Polyols

Based on organophosphorus branched polyols (AEPAs) synthesized using triethanolamine (TEOA), ortho-phosphoric acid (OPA), and polyoxyethylene glycol with MW = 400 (PEG), vapor-permeable polyurethane ionomers (AEPA-PEG-PUs) were obtained. During the synthesis of AEPAs, the reaction of the OPA etherification with polyoxyethylene glycol was studied in a wide temperature range and at different molar ratios of the starting components. It turned out that OPA simultaneously undergoes a catalytically activated etherification reaction with triethanolamine and PEG. After TEOA is fully involved in the etherification reaction, excess OPA does not react with the terminal hydroxyl groups of AEPA-PEG or the remaining amount of PEG. The ortho-phosphoric acid remaining in an unreacted state is involved in associative interactions with the phosphate ions of the AEPA. Increasing the synthesis temperature from 40 °C to 110 °C leads to an increase in OPA conversion. However, for the AEPA-PEG-PU based on AEPA-PEG obtained at 100 °C and 110 °C, ortho-phosphoric acid no longer enters into associative interactions with the phosphate ions of the AEPA. Due to the hydrophilicity of polyoxyethylene glycol, the presence of phosphate ions in the polyurethane structure, and their associative binding with the unreacted ortho-phosphoric acid, the diffusion of water molecules in polyurethanes is enhanced, and high values of vapor permeability and tensile strength were achieved.

Pervaporation Polyurethane Membranes Based on Hyperbranched Organoboron Polyols

On the basis of aminoethers of boric acid (AEBA), polyurethane vapor-permeable and pervaporative membranes were obtained. AEBAs, the structure of which is modified by bulk adducts (EM) of diphenylol propane diglycidyl ether and ethanolamine, were studied. It turned out that AEBA exists in the form of clusters, and the use of EM as a result of partial destruction of associative interactions leads to a significant decrease in the size of AEBA-EM particles and their viscosity compared to unmodified AEBA. The introduction of EM into the composition of AEBA leads to a threefold increase in the vapor permeability of polyurethanes obtained on their basis. The observed effect is explained by the fact that a decrease in the size of clusters leads to loosening of their dense packing. Areas of clustering due to associative interactions of hydroxyl groups, together with the hydrophilic nature of polyoxyethylene glycol, create channels through which water molecules can penetrate. The increase in vapor permeability is accompanied by a multiple increase in the permeability coefficients in the pervaporative dehydration of isopropanol.

Catalytic Etherification of ortho-Phosphoric Acid for the Synthesis of Polyurethane Ionomer Films

The etherification reaction of ortho-phosphoric acid (OPA) with polyoxypropylene glycol in the presence of tertiary amines was studied. The reaction conditions promoting the catalytic activity of triethanolamine (TEOA) and triethylamine (TEA) in the low-temperature etherification of OPA were established. The catalytic activity of TEOA and TEA in the etherification reaction of phosphoric acid is explained by the hydrophobic-hydrophilic interactions of TEA with PPG, leading, as a result of collective interactions, to a specific orientation of polyoxypropylene chains around the tertiary amine. When using triethylamine, complete etherification of OPA occurs, accompanied by the formation of branched OPA ethers terminated by hydroxyl groups and even the formation of polyphosphate structures. When triethanolamine is used as a catalyst, incomplete etherification of OPA with polyoxypropylene glycol occurs and as a result, part of the phosphate anions remain unreacted in the composition of the resulting aminoethers of ortho-phosphoric acid (AEPA). In this case, the hydroxyl groups of triethanolamine are completely involved in the OPA etherification reaction, but the catalytic activity of the tertiary amine weakens due to a decrease in its availability in the branched structure of AEPA. The kinetics of the etherification reaction of OPA by polyoxypropylene glycol catalyzed by TEOA and TEA were studied. It was shown that triethanolamine occupies a central position in the AEPA structure. The physico-mechanical and thermomechanical properties of polyurethane ionomer films obtained on the basis of AEPA synthesized in a wide temperature range were studied.

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.

Gel-polymer electrolytes based on polyurethane ionomers for lithium power sources

Polyurethanes based on the aminoethers of ortho-phosphoric acid and polyisocyanates of an aliphatic nature were studied as a substrate for the preparation of new polymer electrolyte. The conductivity of polyurethane ionomer samples obtained using the optimal amount of aliphatic polyisocyanates and after keeping them in a 1 M LiBF₄ solution in γ-butyrolactone reaches 0.62 mS cm⁻¹. It has been established that the transport of positively charged ions through the polymer matrix is due to the formation of clusters of phosphate ions and their association into the conducting channels. The introduction of carboxylate ions into the conducting channels by modifying the aminoethers of ortho-phosphoric acid with phthalic anhydride leads to an increase in their size and rise in the mobility of cations. As a result, the conductivity of polyurethane gel electrolytes increased to 2.1 mS cm⁻¹.

Polyurethanes based on the aminoethers of ortho-phosphoric acid and polyisocyanates of an aliphatic nature were studied as a substrate for the preparation of a new polymer electrolyte.

Water vapor permeable polyurethane films based on the hyperbranched aminoethers of boric acid

The hyperbranched polymers have drawn intensive attention in the design of macromolecules and functional materials because of their unique physical and chemical properties resulting from the branched architecture and the high number of functional groups. In the present study, by means of light scattering, viscosimetry, thermomechanical analysis, tensile stress–strain, mechanical loss tangent and water vapor permeability measurements, we demonstrate the hierarchical macromolecular organization of organoboron polyurethanes synthesized using sterically hindered amino ethers (AEBA) of boric acid. It is shown that the water vapor permeability of polyurethanes obtained on the basis of sterically hindered aminoethers of boric acid is due to the peculiarities of the chemical structure of AEBA, which can exhibit an ionomeric nature and the presence of steric hindrances created in the hyperbranched structure of AEBA, which can lead to an increase in free volume in such polyurethanes.

It is shown that the water vapor permeability of polyurethanes obtained on the basis of sterically hindered aminoethers of boric acid is due to the peculiarities of the chemical structure of AEBA.