Tris Hydroxymethyl Phosphine Oxide Research Articles

Catalyst-free construction of biomass-based robust and flame-retardant polyurethane foams

This study introduces a green synthesis method for the preparation of flame-retardant biobased polyurethane foams (PUFs) without the use of catalysts. The approach involves the design and utilization of two cardanol-based hydroxyalkyl benzoxazines (CHBzs) capable of self-catalytic foaming through the action of their oxazine rings. Additionally, tris(hydroxymethyl)phosphine oxide (THPO) is incorporated as both a crosslinking agent and a flame-retardant additive during the foaming process to enhance the physical properties and flame retardancy of the resulting PUFs. The thermodynamic performance, compressive strength, and flame-retardant properties of the synthesized foams are analyzed. Furthermore, the morphology of the combustion residues is investigated to understand the combustion process. The results demonstrate that the addition of THPO significantly improves the flame-retardant performance and thermal degradation characteristics of bio-based flame-retardant PUFs. This green synthesis approach offers a promising strategy for the development of sustainable and flame-retardant PUF materials.

Green synthesis of silane-assisted fluorescent carbon dots based on sanding dusts and its application in flame-retardant and anti-leaching wood materials

Novel silane-assisted flame-retardant carbon dots (FR-CDs) were synthesized via the hydrothermal carbonization strategy using recycled wood sanding dusts, tris(hydroxymethyl) phosphine oxide (THPO), phosphoric acid (PA), and amino-silane as precursors. The highly transparent FR-CDs suspension appears pale yellow color under daylight and exhibits a strong fluorescence response to light excitations, which helps to keep the original color of the wood and also has broad application prospects for monitoring the leaching behavior of FR-wood. The as-prepared FR-CDs can be applied in FR-wood materials using the facile dipping process owing to their tiny nanoparticles, uniform dispersion, and numerous nitrogen–phosphorus groups. In the flame test, the FR-CDs treated wood composites emitted little smoke initially and maintained primary carbon layer that did not catch fire for over 180 s. The flame-retardancy of the FR-wood materials was confirmed by the thermo-analysis, limiting oxygen index, exposure to a high heat flux (50 kW/cm2), and the propane blowtorch tests (∼600 °C). Moreover, the formation mechanism of the silane-assisted FR-CDs during hydrothermal process and the FR-wood materials with dipping method was proposed. This study provides a facile and efficient strategy for developing highly transparent and cheap flame retardants for the wood materials, which could expand the application of the wood sanding dusts and the silane-assisted carbon-based nanomaterials in the design of anti-leaching flame-retardant materials.

Insights into the mechanism of the formation of noble metal nanoparticles by in situ NMR spectroscopy.

High-resolution solution Nuclear Magnetic Resonance (NMR) spectroscopy has been used to gain insights into the mechanism of the formation of gold, platinum and gold–platinum alloyed nanoparticles using metal precursors and tetrakis(hydroxymethyl)phosphonium chloride (THPC) as starting materials. THPC is widely used in nanochemistry as a reductant and stabilizer of nanoparticles, however the identity of the species responsible for each role is unknown. The multinuclear study of the reaction media by NMR spectroscopy allowed us to elucidate the structure of all the compounds that participate in the transformation from the metal salt precursor to the reduced metal that forms the nanoparticle, thus clarifying the controversy found in the literature regarding the formation of THPC-based compounds. The progress of the reaction was monitored from the initial moments of the synthesis to the end of the reaction and after long periods of time. Insights into the dual role of THPC were gained, identifying methanol and hydrogen as the actual reducing agents, and tris(hydroxymethyl)phosphine oxide (THPO) as the real stabilizing agent. Finally, the different stabilities of gold and platinum nanoparticles can be attributed to the different catalytic activities of the metals.

Flame retardant polyurethane foam prepared from compatible blends of soybean oil‐based polyol and phosphorus containing polyol

ABSTRACTA phosphorus containing polyether polyol (THPO‐PO) was synthesized by polymerization between tris(hydroxymethyl) phosphine oxide (THPO) and propylene oxide (PO). A soybean oil‐based polyol(SBP) was synthesized from epoxidized soybean oil by ring‐opening reaction with lactic acid. The corresponding polyurethane foams (PUFs) were prepared by mixing SBP with THPO‐PO. The density of these foams decreased as the content of THPO‐PO increased. The yield strength of PUFs was observed to be decreased firstly and then increased with the addition of THPO‐PO. Microphotographs of PUFs were examined by scanning electron microscope which displayed the cells as spherical or polyhedral. The thermal degradation and fire behavior of PUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL‐94 test. Although the thermal stability of PUFs were decreased with increasing THPO‐PO percentage, the flame retardancy of PUFs were improved. The LOI value increased to 27.5 with 40% THPO‐PO. THPO‐PO in sequence worked in inhibiting flame and forming phosphorus‐rich char layer, thus endowing PUFs with the increased flame‐retardant performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45779.

Multiple-Sized Amphiphilic Janus Gold Nanoparticles by Ligand Exchange at Toluene/Water Interface

Amphiphilic Janus gold nanoparticles (GNPs) are prospected to encapsulate drug molecules in cancer therapy and to serve as heterogeneous catalysts at oil/water interfaces, where Janus GNPs with different sizes are required. In this work, multiple-sized precursor GNPs were synthesized by seeded growth method protected with tris(hydroxymethyl)phosphine oxide (THPO) ligand molecule, and a ligand exchange reaction with triphenylphosphine (PPh3) at the toluene/water interface was employed to prepare amphiphilic Janus GNPs. UV-vis and transmission electron microscopy (TEM) analyses indicate that the as-prepared GNPs are nanocrystals with average diameters of 2.3 nm, 9.5 nm, 16.1 nm and 18.8 nm, respectively. Contact angle, Raman and X-ray photonic spectroscopy (XPS) analyses reveal that the self-assembled GNP films exhibit hydrophilic on one side and hydrophobic on another, owing to the adsorption of hydrophilic ligands (THPO and THP) and a similar amount of hydrophobic ligands (PPh3 and PPh3O). Angle-resolved XPS analysis further demonstrates that the individual GNPs actually possess hydrophilic and hydrophobic compartments on the surface, which regularly packed by supramolecular interactions at toluene/water interface to form the self-assembled GNP films.

Electrocatalytic activity of ligand-protected gold particles: formaldehyde oxidation

Tris(hydroxymethyl)phosphine oxide (THPO) and triphenyl phosphine oxide (PPh3O) were introduced onto the surface of colloidal gold nanoparticles (Au NPs), and the effect of capping ligands on the catalytic electrooxidation of formaldehyde was studied voltammetrically by using colloidal Au-NP-modified glassy carbon electrodes (GCEs). This was compared with polycrystalline Au and another Au-NP-modified GCE without a capping molecule. We found that PPh3O causes a larger decrease in the catalytic activity of the Au NPs in liquid than THPO does, indicating that the catalytic activity of the Au NPs is closely associated with the capping ligands. The effect of capping ligands is discussed based on the available surface ratio (ASR), which is defined as the ratio of the total surface area measured electrochemically to the calculated value based on the number and geometry of the Au NPs. These were determined to be 70.6 % for THPO and 0.23 % for PPh3O, respectively. The significant blocking of formaldehyde is probably due to the structure and hydrophobicity of the benzene rings in the PPh3O molecule, which is responsible for the decrease in catalytic activity of the Au NPs.

Feasibility Evaluation of Detecting Hydroxymethylphosphine Oxide In Vivo by 31P-MRS

Application of organophosphorus compounds in biomedicine is attractive because the 31P nucleus is very amenable to study by nuclear magnetic resonance (NMR) techniques, particularly, by in vivo 31P magnetic resonance spectroscopy (31P-MRS). The water-soluble organophosphorus compounds that are non-toxic, exhibit metabolic stability, and show a unique resonance peak in 31P NMR spectroscopy, which could be ideal to be used as probes for 31P-MRS. Here we evaluated the in vivo feasibility of potentially using a hydroxymethylphosphine oxide as a novel probe for 31P-MRS studies using tris(hydroxymethyl)phosphine oxide (THPO) as an example. THPO was synthesized, injected in the normal CF1 mice, and 31P spectra were acquired before and after injection with the coil located on the regions of interest. The NMR signal from the region of interest appeared within one minute of THPO injection. The compound was stable in vivo as no metabolites of THPO were observed. No toxicity was observed after THPO injection in mice. The peak concentrations of THPO in liver and kidney were reached within 15 min and 60 min respectively. THPO was excreted exclusively in urine without undergoing any metabolism indicating that it is very stable under in vivo conditions. These initial studies in normal CF1 mice clearly demonstrate that THPO possess the essential characteristics required for a potential MRS probe. Based on the current preliminary results, we suggest that HMPs, when incorporated into targeted drugs (peptides, proteins, antibodies, etc.), may serve as novel 31P probes for monitoring the drug distribution in vivo by MRS.

Analogues of Acyclic Nucleosides Derived from Tris-(Hydroxymethyl)Phosphine Oxide or Bis-(Hydroxymethyl)Phosphinic Acid Coupled to DNA Nucleobases

A series of novel acyclic nucleoside analogues containing bis-(hydroxymethyl)phosphinic acid (BHPA) or tris(hydroxymethyl)phosphine oxide (THPO) coupled with DNA nucleobases or with 5-fluorouracil were prepared and their antiviral activity was studied against cytomegalovirus (CMV), varicella-zoster virus (VZV), parainfluenza-virus type 3, reovirus-type 1, sindbis, coxsackie B4, punta toro, vesicular stomatitis and respiratory syncytial virus, herpes simplex virus-type 1 (KOS) and type 2 (G), vaccinia virus and herpes simplex virus-1 (TK- KOS ACVr). No specific antiviral effects were noted for any of test compounds against viruses evaluated, except thymine, cytosine and adenine derivatives of BHPA exerting borderline activity against respiratory syncytial virus at the 80 mg/ml concentration.

The electron spin resonance spectra of species resulting from the action of hydroxyl radicals on trishydroxymethylphosphine and related compounds

Trishydroxymethylphosphine, trishydroxymethylphosphine oxide, and tetrakishydroxymethylphosphonium chloride have been allowed to react with hydroxy radicals, and the electron spin resonance spectra of the resulting species observed using a high-speed flow system. In all cases the only radicals observed were those due to abstraction of a hydrogen atom in the position α to the hydroxyl group, and for the phosphine, radicals arising from both the phosphorus-protonated and the non-protonated species could be detected. The values of the hyperfine coupling constants (1H and 31P) are discussed.

HYDROXYMETHYL PHOSPHORUS DERIVATIVES FROM TETRAKIS(HYDROXYMETHYL) PHOSPHONIUM CHLORIDE. REACTION WITH LEAD CARBONATE AND OXIDE

A novel and convenient method has been developed for the preparation of tris(hydroxy-methyl) phosphine oxide (THPO) from tetrakis (hydroxymethyl) phosphonium chloride (THPC). The method consists essentially of oxidative deformylation of THPC with lead carbonate in n-propyl alcohol. The reaction is facilitated by azeotropic distillation of di-n-propylformal and n -propyl alcohol.The reaction of THPC with lead carbonate as well as with lead oxide has been studied in detail in aqueous solution and in n-propyl alcohol. The reaction proceeds via the initial formation of tetrakis(hydroxymethyl) phosphonium hydroxide (THPOH) followed by deformylation to tris (hydroxymethyl) phosphine (THP). THP then undergoes oxidation by air as well as by lead carbonate or oxide to THPO. If air is bubbled through the mixture at elevated temperatures, atmospheric oxidation predominates with little or no oxidation by the lead compound.Depending upon the reaction conditions, a phosphonium hydroxide, a phosphine, or a phosphine oxide are products of the reaction of tetrakis(hydoxymethyl) phosphonium chloride with lead carbonate or oxide.