Trimethyl Phosphate Research Articles

Development and validation of skeletal/global mechanisms describing TMP-based flame inhibition

Phosphorus-based chemical compounds such as trimethylphosphate (TMP) and dimethylmethylphosphonate (DMMP) are widely used as fire suppressants. The detailed chemical kinetic mechanism by Jayaweera et al. [1] is frequently used to describe the flame inhibition process. The elementary reaction steps can be categorised into inhibitor molecule decomposition steps and radical recombination steps. The present work shows that the inhibitor decomposition process can be adequately represented by a single irreversible step for TMP. Subsequently, graph-based mechanism reduction techniques and sensitivity analysis are employed to extract the key catalytic inhibition reactions. The resultant skeletal kinetic mechanism consists of 4 species and 7 reactions. The present work also proposes a global mechanism containing 3 species and 3 reactions. In the global model, flame inhibition is described by a 2-step model. These models are validated in premixed and diffusion flame environments. Excellent agreement with the experimental measurements and detailed model predictions are obtained. Development of the skeletal/global models reduces the computational time by around 82% compared to the detailed model.

LiNO3 and TMP enabled high voltage room-temperature solid-state lithium metal battery

The poor interfacial contact and notorious instability issues between solid electrolyte and electrodes seriously handicap the practical applications of solid-state lithium metal batteries (LMBs). In-situ polymerization is a considerable choice to upgrade the interfacial transport properties by directly curing the liquid precursor inside the cell. Herein, a ∼ 17 μm poly(ethylene glycol) methyl ether methacrylate (PEGMEA) based solid polymer electrolyte (SPE) is prepared by this method. Trimethyl phosphate (TMP) and LiNO3 are introduced to promote the ion transport as well as enhance the electrodes/electrolyte interfacial stability. Interestingly, although LiNO3 increases the electrolyte’s glass transition temperature thus hinders the anion transport, while higher Li+ conductivity is obtained due to the weakened interaction between Li+ and its ligands, ethylene oxide (EO) and TMP. The optimal electrolyte (PTLiN1) shows an acceptable ionic conductivity of 1.2 × 10-4 S cm−1 at 55°C and lithium ion transference number (tLi+) of 0.46, which enables the Li||Li symmetric cells to run stability within 1500 h (0.2 mA cm−2, 0.4 mAh cm−2) at 55°C and 1000 h (0.1 mA cm−2, 0.2 mAh cm−2) at 25°C. Meanwhile, the LiFePO4||Li cell with PTLiN1 shows superior long cycle lifetime with a high capacity retention of 88.4% over 300 cycles at 0.5 C. The cells coupled with LiCoO2 can even work stably under room temperature in the voltage range of 3.0 ∼ 4.3 V. Pouch cells based on PTLiN1 are also prepared and show outstanding flexibility and high security, which provides new idea for the development of economical and convenient solid-state batteries.

Cellulose@PO3H: As an Efficient and Recyclable Ionic Liquid-Enabled Catalytic Greener Approach to One-Step Synthesis of Flavoring Ketones

Cellulose (CL) is widely available from the renewable biomaterial on the earth with a large number of hydroxyl functionalities on its surface. The appropriate modification of these functionalities results in the acidic and basic nature of the surface. In this work, the phosphoric group-functionalized CL ionic liquid (IL) has been successfully synthesized through phosphorylation of the CL surface. The phosphorus functionalization of CL has been carried out in two steps; first, synthesis of IL (3, 5-lutidinium methyl phosphate [Lut][(MeO)(H)PO2]), followed by phosphorylation of cellulose (CLP-IL). Subsequently, CLP-IL has been characterized by various physicochemical techniques. Significant changes in the activity were observed, with marginal changes in the structural and morphological properties of the native CL. CLP-IL has been utilized to synthesize industrially important flavoring ketones (FKs) via one-step alkylation–decarboxylation of active methylene compounds with substituted benzyl alcohols and halides. The functionalized CL IL could be quickly recovered in water and recycled at least five times without losing the catalytic activity. The optimized protocol has been successfully employed for the synthesis of FKs with an excellent conversion of substituted benzyl carbons in the range (90–100%) with 70–90% isolated yield of desired market valuable products. Furthermore, the mechanism was established by identifying the intermediates by physicochemical methods.

Finding a novel electrolyte solution of lithium-ion batteries using an autonomous search system based on ensemble optimization

For an autonomous search for electrolyte solutions in electrochemistry, we performed a search task using a parallel Bayesian optimization method with the best composition with maximum lithium (Li) ion conductivity in a mixture of four lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) solutions: propylene carbonate (PC), γ-butyrolactone (GBL), tetraethylene glycol diethyl ether (TGDE), and trimethyl phosphate (TMP). The maximum ionic conductivity was achieved using a mixed solution of 98 vol% GBL and 2 vol% TGDE and showed a high Li ionic conductivity in manual measurements. Furthermore, molecular dynamics simulations of a similar electrolyte implied that the small solvation shell of Li-TGDE caused an increase in the ionic conductivity. The reason for this increase is that the dilute TGDE molecules in the GBL solution can be associated with dilute Li ions.

Transformation behaviour of salts composed of calcium ions and phosphate esters with different linear alkyl chain structures in a simulated body fluid modified with alkaline phosphatase

ABSTRACT Ceramic biomaterials have been used for the treatment of bone defects and have stimulated intense research on such materials. We have previously reported that a salt composed of calcium ions and a phosphate ester (SCPE) transformed into hydroxyapatite (HAp) in a simulated body fluid (SBF) modified with alkaline phosphatase (ALP), and proposed SCPEs as a new category of ceramic biomaterials, namely bioresponsive ceramics. However, the factors that affect the transformation of SCPEs to HAp in the SBF remained unclear. Therefore, in this study, we investigated the behaviour of calcium salts of methyl phosphate (CaMeP), ethyl phosphate (CaEtP), butyl phosphate (CaBuP), and dodecyl phosphate (CaDoP) in SBF with and without ALP modification. For the standard SBF, an X-ray diffraction (XRD) analysis indicated that these SCPEs did not readily transform into calcium phosphate. However, CaMeP, CaEtP, and CaBuP were transformed into HAp and octacalcium phosphate in the SBF modified with ALP; therefore, these SCPEs can be categorised as bioresponsive ceramics. Although CaDoP did not exhibit a sufficient response to ALP to be detected by XRD, it is likely to be a bioresponsive ceramic based on the results of morphological observations. The transformation rate for the SCPEs decreased with increasing size of the linear alkyl group of the phosphate esters. The rate-determining steps for the transformation reaction of the SCPEs were changed from the dissolution of the SCPEs to the hydrolysis of the phosphate esters with increasing size of the phosphate ester alkyl groups. These findings contribute to designing novel bioresponsive ceramic biomaterials.

Synergistically reinforced poly(ethylene oxide)-based composite electrolyte for high-temperature lithium metal batteries

Traditional liquid lithium-ion batteries are not applicable for extreme temperatures, due to the shrinkage of separators and volatility of electrolytes. It is necessary to develop advanced electrolytes with desirable characteristics in terms of thermal stability, electrochemical stability and mechanical properties. Solid-state electrolytes, such as polyethylene oxide (PEO), outperform other types and bring the opportunity to realize the high-temperature lithium-ion batteries. However, the softness of PEO at elevated temperatures leads to battery failure. In this work, a three-dimensional fiber-network-reinforced PEO-based composite polymer electrolyte is prepared. The introduced polyimide (PI) framework and trimethyl phosphate (TMP) plasticizer decrease the crystallinity of PEO and increase the ionic conductivity at 30 °C from 8.79 × 10−6 S cm−1 to 4.70 × 10−5 S cm−1. In addition, the PEO bonds tightly with PI fiber network, improving both the mechanical strength and thermal stability of the prepared electrolyte. With the above strategies, the working temperature range of the PEO-based electrolytes is greatly expanded. The LiFePO4/Li cell assembled with the PI-PEO-TMP electrolyte stably performs over 300 cycles at 120 °C. Even at 140 °C, the cell still survives 80 cycles. These excellent performances demonstrate the potential application of the PI-PEO-TMP electrolyte in developing safe and high-temperature lithium batteries.

Comparable Investigation of Phosphorus-Based Flame Retardant Electrolytes on LiFePO4 Cathodes

Improving the flame retardant and electrochemical properties of electrolytes is of great significance to enhance the safety of lithium-ion batteries (LIBs). In this work, the effect of cresyl diphenyl phosphate (CDP), dimethyl methyl phosphonate (DMMP), trimethyl phosphate (TMP) and triphenyl phosphate (TPP) as flame retardant additives in the standard electrolyte on the performance of LiFePO4/Li cell are comprehensively studied. The results show that when the mass fraction of flame retardant is less than 20%, the purpose of flame retardant can be achieved in the electrolyte. When the cells without and with 20 wt% of CDP, DMMP, TMP, and TPP additives are, respectively, their capacity retentions are 80, 46, 82, 84, and 57% after 100 cycles at 0.5C. According to characterization analysis, DMMP and TMP can facilitate the formation of stable interface films on cathode and subsequently improve the battery performance. Compared with expensive or complicated synthetic flame retardants, conventional flame retardants like CDP, DMMP, TMP, and TPP have great potential for application in electrolytes to improve the safety of LIBs. This work can provide useful scientific research and industry in the study of phosphorus-based flame retardant electrolytes.

Promising low-viscosity phosphorus-containing epoxy compounds: Features of interaction with aromatic amines

The interaction of glycidyl esters of phosphorus acids (GEF) with aromatic amine hardeners has been studied. A comparative analysis of the reactivity of different GEF (triglycidyl phosphate (TGFT), diglycidyl methyl phosphate (DGMFT), diglycidyl methyl phosphonate (DGMFN)) has been carried out. The activity of amine hardeners in interaction with GEF has been also compared. Kinetic parameters for the curing reaction have been calculated using Thermokinetics software, and the mode of the interaction of phosphorus-containing epoxy oligomers with aromatic amines has been assessed. Complex structures have been optimized using DFT computations at the CAM-B3LYP/TZVPP level with accounting for solvent effects using the C-PCM model. Thermophysical and flame-retardant characteristics of cured phosphorus-containing epoxy polymers have been investigated. It has been shown that epoxy polymers based on GEF and amine aromatic hardeners have high values glass transition temperature. The resulting binder is self-extinguishing and displays promise for use in the RTM process.

Occurrence of trimethyl phosphate and triethyl phosphate in a municipal wastewater treatment plant and human urine

ABSTRACT Trimethyl phosphate (TMP) and triethyl phosphate (TEP) are extensively used as flame retardants, but their analytical methods are scarce. In this study, a robust method for both TMP and TEP in environmental water and human urine was developed by coupling of solid phase extraction (SPE) with liquid chromatography-tandem mass spectrometry (LC-MS/MS). For both TMP and TEP, the method showed good recoveries (>81%) and precisions (RSD < 5%), as well as a limit of quantification of 3 ng/L for water and 40 ng/L for urine samples, respectively. Through this method, the occurrence of TMP and TEP in municipal wastewater treatment plant (WWTP) were profiled and the anoxic step was found as the key role for their removal. Furthermore, TEP (110-2470 ng/L) was detected in all urine samples with generally higher concentration than TMP (70–2330 ng/L), which agreed with their occurrence profiles in the influent and effluent of the WWTP.

Nonflammable, robust and flexible electrolytes enabled by phosphate coupled polymer–polymer for Li-metal batteries

Liquid organic electrolytes commonly employed in commercial Li-ion batteries suffer from safety issues such as flammability and explosions. Replacing liquid electrolytes with nonflammable electrolytes has become increasingly attractive in the development of safe, high-energy Li-metal batteries (LMBs). In this work, nonflammable, robust, and flexible composite polymer–polymer electrolytes (PPEs) were successfully fabricated by flame-retardant solution casting with polyimide (PI) and polyvinylidene fluoride (PVDF). The optimized nonflammable PPEs (e.g., PPE-50) demonstrate not only good mechanical properties (i.e., a high tensile strength of 29.6 MPa with an elongation at break of 87.2%), but also high Li salts dissolubility, the former of which ensures the suppression of Li dendrites, while the latter further improves the ionic conductivity (∼1.86 × 10−4 S cm−1 at 30 °C). The resulting symmetric cells (Li|PPE-50|Li) offer excellent Li stripping and plating stability for 1000 h at 0.5 mA cm−2/0.25 mAh cm−2 and 600 h at 2.0 mA cm−2/1.0 mAh cm−2. In addition, the LiFePO4|PPE-50|Li half cells show high cycling performance (e.g., a reversible discharge capacity of 135.9 mAh g−1 after 300 cycles at 1C) and rate capability (e.g., 117.2 mAh g−1 at 4C). The PPE-50 is also compatible with a high-voltage cathode (e.g., LiNi0.5Mn0.3Co0.2O2), and the resulting batteries demonstrate long-term cycling stability with a high cut-off voltage of 4.5 V vs. Li/Li+. Because of the incorporation of a mechanically robust and thermally stable PI, a polar PVDF, and flame-retardant trimethyl phosphate (TMP) within PPEs, as well as the coordination between Li salts and TMP, and the interaction between Li salts and polymers (especially between Li bis(oxalato)borate) and PI, as well as the bis(oxalato)borate anion and PI), PPEs show great potential for practical and high-energy LMBs without safety concerns.

Stereospecific Construction of Quaternary Carbon Stereocenters from Quaternary Carbon Stereocenters.

Organoaluminum species promote a smooth nucleophilic substitution at the quaternary carbon stereocenter of stereodefined polysubstituted cyclopropyl methyl phosphate with a complete inversion of configuration, even when more reactive functional groups are present. The regio- and diastereoselectivity of the substitution is attributed to the existence of a bicyclobutonium intermediate.

Eco-conception of Highly Salt-Tolerant Alkyl Ether Carboxylate Hydrotropes with a Glyceryl Spacer.

New alkyl ether carboxylates with a glyceryl spacer instead of ethylene glycol units have been synthesised using environmentally friendly methodology. A cascade synthesis of acetalisation and hydrogenolysis was developed to obtain products containing an alkyl chain linked to a glycerol unit bearing a polar carboxylate head. These products were methylated by using trimethyl phosphate to observe the influence of a free or methoxylated alcohol on the physicochemical properties. Finally, saponification gave the carboxylate anionic group of the new hydrotropes. Studying the amphiphilicity, the tolerance to sodium and calcium ions, and the solubilising power of these bio-based ionic/nonionic hydrotropes has shown that they exhibit significantly improved application properties compared to similar petro-based hydrotropes.

The gas phase retention volume behavior of organophosphate esters on polyurethane foam

In this study, the gas-phase retention volume behavior of four highly volatile organophosphate esters (OPEs) on polyurethane foam (PUF) was studied using a frontal chromatogram. The breakthrough volumes (VB) of trimethyl phosphate (TMP), triethyl phosphate (TEP), tripropyl phosphate (TPrP), and tri-n-butyl phosphate (TnBP) were 0.33, 0.59, 10.5, and 32.4 m3, respectively. A significant negative correlation was found between the logarithm value of VB and the subcooled liquid vapor pressure (PL) with an r2 of 0.905, indicating that the vapor penetration depends on both the volatility and total air volume. The enthalpy of desorption and vaporization (ΔHS−ΔHV) showed a significant difference between the tested OPEs and polycyclic aromatic hydrocarbons (PAHs), revealing that the strength of the sorption interaction of the tested OPEs vapor on PUF should be different from that of PAHs. The PUF-air partition coefficients (KPUF-air) of the tested OPEs ranged from 4.3 to 8.1, which were lower than those of three-to four-ring PAHs (7.02–10.2) and organochlorines (8.01–9.72), revealing that the partition of highly volatile OPEs on PUF is lower than that of low-volatile compounds. The PUF/XAD cartridge improved the absorption efficiency of the tested OPEs; however, its sorptive capacity was still limited.

Advanced Nonflammable Localized High‐Concentration Electrolyte For High Energy Density Lithium Battery

The key to realize long‐life high energy density lithium batteries is to exploit functional electrolytes capable of stabilizing both high voltage cathode and lithium anode. The emergence of localized high‐concentration electrolytes (LHCEs) shows great promise for ameliorating the above‐mentioned interfacial issues. In this work, a lithium difluoro(oxalate)borate (LiDFOB) based nonflammable dual‐anion LHCE is designed and prepared. Dissolving in the mixture of trimethyl phosphate (TMP) /1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropylether (D2), the continuously consumption of LiDFOB is suppressed by simply introducing lithium nitrate (LiNO3). Meantime, as most of the TMP molecular are coordinated with Li+, the electrolyte does not show incompatibility issue between neither metal lithium nor graphite anode. Therefore, it demonstrates excellent capability in stabilizing the interface of Ni‐rich cathode and regulating lithium deposition morphology. The Li||LiNi0.87Co0.08Mn0.05O2 (NCM87) batteries exhibit high capacity retention of more than 90% after 200 cycles even under the high cutoff voltage of 4.5 V, 1 C rate. This study offers a prospective method to develop safe electrolytes suitable for high voltage applications, thus providing higher energy densities.

The methyl phosphate capping enzyme Bmc1/Bin3 is a stable component of the fission yeast telomerase holoenzyme

The telomerase holoenzyme is critical for maintaining eukaryotic genome integrity. In addition to a reverse transcriptase and an RNA template, telomerase contains additional proteins that protect the telomerase RNA and promote holoenzyme assembly. Here we report that the methyl phosphate capping enzyme (MePCE) Bmc1/Bin3 is a stable component of the S. pombe telomerase holoenzyme. Bmc1 associates with the telomerase holoenzyme and U6 snRNA through an interaction with the recently described LARP7 family member Pof8, and we demonstrate that these two factors are evolutionarily linked in fungi. Our data suggest that the association of Bmc1 with telomerase is independent of its methyltransferase activity, but rather that Bmc1 functions in telomerase holoenzyme assembly by promoting TER1 accumulation and Pof8 recruitment to TER1. Taken together, this work yields new insight into the composition, assembly, and regulation of the telomerase holoenzyme in fission yeast as well as the breadth of its evolutionary conservation.

A Mild Heteroatom (O-, N-, and S-) Methylation Protocol Using Trimethyl Phosphate (TMP)–Ca(OH)2Combination

AbstractA mild heteroatom methylation protocol using trimethyl phosphate (TMP)–Ca(OH)2 combination has been developed, which proceeds in DMF, or water, or under neat conditions, at 80 °C or at room temperature. A series of O-, N-, and S-nucleophiles, including phenols, sulfonamides, N-heterocycles, such as 9H-carbazole, indole derivatives, and 1,8-naphthalimide, and aryl/alkyl thiols, are suitable substrates for this protocol. The high efficiency, operational simplicity, scalability, cost-efficiency, and environmentally friendly nature of this protocol make it an attractive alternative to the conventional base-promoted heteroatom methylation procedures.

Flammability properties of intumescent vinyl acetate–ethylene copolymer emulsion including natural carbonization agent

Melamine amino trimethyl phosphate (M-AT) has been mixed with bio-based starch, chitosan, or sodium lignosulfonate (SL), and used to prepare an intumescent flame retardant (IFR) vinyl acetate-ethylene copolymer emulsion (VAE), which might be used for the formulation of adhesives, coatings, etc. The goal was to meet the performance requirements especially with respect to flame retardance and mechanical properties. The flammability of VAE adhesives was assessed using limiting oxygen index (LOI), UL-94 vertical burning, and cone calorimetry tests (CCT). The presence of 30 wt% of the M-AT/SL compounds (mass ratio of M-AT to SL was 3:1) in VAE polymer brought a 73% reduction in peak of heat release rate (139.2–37.1 kW/m2) in CCT. The LOI was increased to 31.5 from 20, the UL94 grade was upgraded to V-0 (sample thickness: 5 mm). The formation of bubble-shaped char layer can be promoted by polyphosphoric acid and benzenesulfonic acid along with ammonia and sulfur dioxide, which generated by the thermal decomposition of synthesized M-AT and SL during combustion of the polymer. In addition, the incorporation of 30 wt% M-AT/SL compounds in VAE matrix leaded to a 56% and 40% increasement in tensile strength and elongation at break tests, respectively compared to the pure one. This work offers a green and novel method for the production of high-performance VAE adhesives with fire resistance properties.

A putative cap binding protein and the methyl phosphate capping enzyme Bin3/MePCE function in telomerase biogenesis

Telomerase reverse transcriptase (TERT) and the noncoding telomerase RNA (TR) subunit constitute the core of telomerase. Additional subunits are required for ribonucleoprotein complex assembly and in some cases remain stably associated with the active holoenzyme. Pof8, a member of the LARP7 protein family is such a constitutive component of telomerase in fission yeast. Using affinity purification of Pof8, we have identified two previously uncharacterized proteins that form a complex with Pof8 and participate in telomerase biogenesis. Both proteins participate in ribonucleoprotein complex assembly and are required for wildtype telomerase activity and telomere length maintenance. One factor we named Thc1 (Telomerase Holoenzyme Component 1) shares structural similarity with the nuclear cap binding complex and the poly-adenosine ribonuclease (PARN), the other is the ortholog of the methyl phosphate capping enzyme (Bin3/MePCE) in metazoans and was named Bmc1 (Bin3/MePCE 1) to reflect its evolutionary roots. Thc1 and Bmc1 function together with Pof8 in recognizing correctly folded telomerase RNA and promoting the recruitment of the Lsm2-8 complex and the catalytic subunit to assemble functional telomerase.

Metabolic Profiling Analysis of Liver in Landes Geese During the Formation of Fatty Liver via GC-TOF/MS.

Fatty liver production results from the process of overfeeding geese, inducing a dramatic increase in de novo liver lipogenesis. To investigate the alteration of liver metabolites by overfeeding, especially lipid metabolites, and the potential pathways causing these changes, 60 Landes geese at 65 days old were raised in three groups with 20 geese per group, namely, the D0 group (free from gavage), D7 group (overfeeding for 7 days), and D25 group (overfeeding for 25 days). At 90 days old, segments of liver tissue were collected from 10 geese of each group for gas chromatography time-of-flight/mass spectrometry (GC-TOF/MS) analysis. A large number of endogenous molecules in the livers of geese were altered dramatically by overfeeding. In the livers of overfed geese, the level of oleic acid was observed to continuously increase, while the levels of phenylalanine, methyl phosphate, sulfuric acid, and 3-hydroxybenzaldehyde were decreased. The most significantly different metabolites were enriched in amino acid, lipid, and nucleotide metabolism pathways. The present study further supports the idea that Landes geese efficiently produce fatty liver, and potential biomarkers and disturbed metabolic pathways during the process of forming fatty liver were identified. In conclusion, this study might provide some insights into the underlying mechanisms of fatty liver formation.

Deciphering the Role of Fluoroethylene Carbonate towards Highly Reversible Sodium Metal Anodes.

Sodium metal anodes (SMAs) suffer from extremely low reversibility (<20%) in carbonate-based electrolytes—this piece of knowledge gained from previous studies has ruled out the application of carbonate solvents for sodium metal batteries. Here, we overturn this conclusion by incorporating fluoroethylene carbonate (FEC) as cosolvent that renders a Na plating/stripping efficiency of >95% with conventional NaPF6 salt at a regular concentration (1.0 M). The peculiar role of FEC is firstly unraveled via its involvement into the solvation structure, where a threshold FEC concentration with a coordination number>1.2 is needed in guaranteeing high Na reversibility over the long-term. Specifically, by incorporating an average number of 1.2 FEC molecules into the primary Na+ solvation sheath, lowest unoccupied molecular orbital (LUMO) levels of such Na+-FEC solvates undergo further decrease, with spin electrons residing either on the O=CO(O) moiety of FEC or sharing between Na+ and its C=O bond, which ensures a prior FEC decomposition in passivating the Na surface against other carbonate molecules. Further, by adopting cryogenic transmission electron microscopy (cryo-TEM), we found that the Na filaments grow into substantially larger diameter from ~400 nm to >1 μm with addition of FEC upon the threshold value. A highly crystalline and much thinner (~40 nm) solid-electrolyte interphase (SEI) is consequently observed to uniformly wrap the Na surface, in contrast to the severely corroded Na as retrieved from the blank electrolyte. The potence of FEC is further demonstrated in a series of “corrosive solvents” such as ethyl acetate (EA), trimethyl phosphate (TMP), and acetonitrile (AN), enabling highly reversible SMAs in the otherwise unusable solvent systems.