K. Troev

A novel approach to recycling of polyurethanes: chemical degradation of flexible polyurethane foams by triethyl phosphate

It was established that flexible polyurethane foams based on polyester or polyether polyol and toluene diisocyanate can be converted quantitatively into liquid form by treatment with triethyl phosphate (C2H5O)3P(O). Structures of the degraded products were studied by 1H, 13C and 31P NMR spectroscopy. The degraded products are phosphorus containing oligourethanes. The likely mechanism is presented.

REVIEW CHARACTERISTIC REACTIONS OF THE ALKOXY GROUPS OF THE ACID DIESTERS OF PHOSPHOROUS ACID

Abstract This review presents the characteristic reactions of the alkoxy group of the acid diesters of phosphorous acid (RO)2 P(O)H: transesterification—with the phosphorus atom as the reaction center; alkylation—with the α-carbon atom as the reaction center; dealkylation—with the α-carbon atom as the reaction center. The possibilities of these reactions in the synthesis of end products with various structures and compositions are demonstrated. The perspectives for the practical application of these esters of phosphorous acid are discussed.

Synthesis, cytotoxicity and clastogenicity of novel α-aminophosphonic acids

Summary.α-Ethyl-N-(phosphonomethyl) glycine is synthesized and characterized by NMR and FAB spectroscopy. The cytotoxicity, clastogenic and antiproliferative effect of 3-ethyl-2-hydroxyl-2-oxo-1,4,2-oxazaphosphorinane, sodium salt of 3-ethyl-2-hydroxyl-2-oxo-1,4,2-oxazaphosphorinane, α-ethyl-α-N-(hydroxyethylamino) methylphosphonic acid, α-ethyl-N-(phosphonomethyl) glycine, α-ethyl-N-(phosphonomethyl) glycine isopropylammonium salt, glyphosate isopropylammonium salt are tested.

Functionalization of poly(oxyethylene phosphonate) under phase-transfer catalyst conditions

Abstract The feasibility of the reaction of poly(oxyethylene phosphonate) 1 with chloroacetone under phase-transfer catalysis conditions for the preparation of poly(oxyethylene phosphonate)s bearing α-hydroxyl and oxirane groups in the side chains has been investigated. It has been established that the first stage of the reaction involves addition of the P–H to the carbonyl bond of chloroacetone resulting in poly(oxyethylene α-hydroxy phosphonate). During the second stage of the reaction, the oxirane formation proceeds via elimination of chloride ion. It is possible to direct the reaction to produce poly(oxyethylene phosphonate) 2, bearing 86.2% α-hydroxyl groups, or to poly(oxyethylene phosphonate) 3, bearing 91% oxirane groups. The structure of the products has been proved by means of 1H, 13C and 31P NMR spectroscopy. Thus design poly(oxyethylene phosphonate)s bearing α-hydroxyl and oxirane groups are of interest as polymer-carriers of drugs and polymers with their own bioactivity. The cytotoxicity of poly(oxyethylene phosphonate), poly(oxyethylene phosphonate)s bearing α-hydroxyl and oxirane groups has been studied.

Direct usage of products of poly(ethylene terephthalate) glycolysis for manufacturing of glass-fibre-reinforced plastics

The paper reports on the possibility of direct use of some products of poly(ethylene terephthalate) glycolysis, bis(2-hydroxyethyl) terephthalate and ethylene glycol mainly, in the process of glass-fibre-reinforced plastics manufacturing. The addition of toluene diisocyanate as an intermediating agent was an important prerequisite for their incorporation into the resin composition. The composites containing products of poly(ethylene terephthalate) glycolysis up to 15% mass display improved mechanical properties in comparison with the unmodified samples.

Chemical degradation of polyurethanes: Degradation of flexible polyester polyurethane foam by phosphonic acid dialkyl esters

Flexible polyurethane foam based on toluene diisocyanate and polyester polyol has been liquefied by treatment with either dimethyl phosphonate (CH3O)2P(O)H or diethyl phosphonate (C2H5O)2P(O)H at 160°C. The product degraded has been studies by 1H, 13C, and 31P nuclear magnetic resonance (NMR) spectroscopy. The likely reaction mechanism is presented.

Study on the Atherton–Todd reaction mechanism

A new mechanism of the Atherton–Todd reaction is discussed. The first step of the reaction between diesters of H-phosphonic acid and carbon tetrachloride in the presence of a base, commonly triethylamine, is a salt formation between carbon tetrachloride and the base [amine·Cl]+CCl3−. The trichloromethanide anion [CCl3−] deprotonates dialkyl H-phosphonate to form chloroform and dialkyl phosphonate anion [(RO)2P(O)]−. The latter anion reacts with the chlorine cation to furnish dialkyl chlorophosphate. Based on these findings the reaction has been applied for the oxidation of poly(alkylene H-phosphonate)s to the corresponding poly(alkylene chlorophosphate)s via the Atherton–Todd reaction.

Synthesis of poly(oxyethylene phosphonate)s bearing oxirane groups in the side chain

The interaction between poly(oxyethylene phosphonate)s and 1,2-epoxy-7-octene has been investigated. It has been established that in the presence of benzoyl peroxide there proceeds a selective addition of the P-H group to the C=C double bond. Poly( oxyethylene phosphonate)s bearing oxirane groups in the side chain have been synthesized. The new polymers can be used as polymer carriers of drugs.

Phosphorus- and metal-containing poly(ethylene terephthalate)—2. Phosphorus-, calcium- and chlorine-containing polymer

Abstract A phosphorus-, calcium- and chlorine-containing oligomer was used as a comonomer, including ionic bonds in its molecule, for the synthesis of poly(ethylene terephthalate). With contents of 1.0% P, Ca 1.2% and Cl 0.09%, the resin has the following characteristics: ηrel = 1.315; COOH 18.12 mg.eqv KOH/g · 10−6, m.p. 261.5°, oligomers 2.12%; diethylene glycol 1.18%. The comonomer catalyses the polycondensation and has a thermal stabilizing effect.

STUDIES ON THE STABILITIES OF ALKYLMETHYLAMMONIUM SALTS OF MONOMETHYL ESTERS OF PHOSPHONIC ACIDS

Abstract It has been shown by 1H NMR spectroscopy that alkylmethylammonium salts of monomethyl esters of phosphonic acids having the general formula [RN+H2CH3][−OPH(O)(OCH3)] are unstable. At ambient temperature these salts convert into the corresponding alkylammonium salts [RN+H3][−OPH(O)(OCH3)]. The effect of different substituents R on the stability of these alkylammonium cations is discussed.