Phosphonium Sulfate Research Articles

Synthesis of a novel azaphosphorine flame retardant and its application in epoxy resins

ABSTRACTA novel PCN bond containing azaphosphorine, 5‐(4‐hydroxy)anilinomethyl‐1,3‐di(4‐hydroxy)phenyl‐1,3,5‐diazaphosphorinane (ADDPP‐OH), which could be used as both a cocuring agent and a flame‐retarding agent for epoxy resins (EPs), was synthesized from tetrakis(hydroxymethyl)phosphonium sulfate and characterized by FTIR, 1H‐NMR, 13C‐NMR, 31P‐NMR, and so on. Compared with the pure EP, the ADDPP‐OH–EP composites showed increased decomposition temperatures and char yields. When the content of ADDPP‐OH was 10 wt %, the cured EP composite possessed a limiting oxygen index value of 33.7% and passed the V‐0 rating of the UL‐94 test. The mechanical properties of the ADDPP‐OH–EP composites was improved because of the increased crosslinking density. In addition, the morphology of the residual char indicated an intumescent and multiporous structure in the inner space and a compact and continual appearance in the outer layer; this was important in preventing the materials from burning further. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45721.

Laboratory testing of enhanced biocide mitigation of an oilfield biofilm and its microbiologically influenced corrosion of carbon steel in the presence of oilfield chemicals

Microbiologically influenced corrosion (MIC) is prevalent in the oil and gas industry. Problematic biofilms cause MIC and reservoir souring. A high biocide concentration is usually required to mitigate biofilms compared with planktonic cells. This causes economic and environmental concerns. A biocide enhancer can make a biocide more effective using the same or lower biocide dosage. In this work, an equimolar mixture of 100 ppm (w/w) of four D-amino acids (D-methionine, D-tyrosine, D-tryptophan, and D-leucine) labeled as D-mix enhanced 100 ppm tetrakis (hydroxymethyl) phosphonium sulfate (THPS) against a field biofilm consortium on C1018 carbon steel coupons. In order to test chemical compatibilities, D-amino acids were added together with THPS and enhanced oil recovery chemicals (a polymer, a surfactant, a corrosion inhibitor, and a scale inhibitor) to treat the mature biofilm consortium. After a 7-day biofilm removal test in 125 ml anaerobic vials, the cocktail of 100 ppm THPS +100 ppm D-mix achieved extra logs of reduction in sessile cell counts compared with the 100 ppm THPS alone treatment. The combination also achieved lower weight loss and smaller maximum pit depths. Electrochemical tests corroborated the weight loss and pitting data.

Enhanced Biocide Treatments with D-amino Acid Mixtures against a Biofilm Consortium from a Water Cooling Tower.

Different species of microbes form mixed-culture biofilms in cooling water systems. They cause microbiologically influenced corrosion (MIC) and biofouling, leading to increased operational and maintenance costs. In this work, two D-amino acid mixtures were found to enhance two non-oxidizing biocides [tetrakis hydroxymethyl phosphonium sulfate (THPS) and NALCO 7330 (isothiazoline derivatives)] and one oxidizing biocide [bleach (NaClO)] against a biofilm consortium from a water cooling tower in lab tests. Fifty ppm (w/w) of an equimass mixture of D-methionine, D-leucine, D-tyrosine, D-tryptophan, D-serine, D-threonine, D-phenylalanine, and D-valine (D8) enhanced 15 ppm THPS and 15 ppm NALCO 7330 with similar efficacies achieved by the 30 ppm THPS alone treatment and the 30 ppm NALCO 7330 alone treatment, respectively in the single-batch 3-h biofilm removal test. A sequential treatment method was used to enhance bleach because D-amino acids react with bleach. After a 4-h biofilm removal test, the sequential treatment of 5 ppm bleach followed by 50 ppm D8 achieved extra 1-log reduction in sessile cell counts of acid producing bacteria, sulfate reducing bacteria, and general heterotrophic bacteria compared with the 5 ppm bleach alone treatment. The 10 ppm bleach alone treatment showed a similar efficacy with the sequential treatment of 5 ppm bleach followed by 50 ppm D8. The efficacy of D8 was found better than that of D4 (an equimass mixture of D-methionine, D-leucine, D-tyrosine, and D-tryptophan) in the enhancement of the three individual biocides against the biofilm consortium.

Influence of Thermophilic Bacteria on Corrosion of Carbon Steel in Hyper Chloride Environment

The present study evaluates, the oxidation behaviour of thermophilic bacteria Geobacillus thermoparaffinivorans IR2, Geobacillus stearothermophillus IR4 and Bacillus licheniformis MN6 on carbon steel API 5 LX by weight loss, electrochemical studies (impedance and polarization analysis) and surface analysis (X-ray diffraction spectroscopy). The presence of IR2, IR4 and MN6 showed highest corrosion rate (CR) of 2.51, 2.82 and 2.41 mm/year, respectively, than the abiotic control (0.95 mm/year). Whereas in the presence of biocide tetrakis (hydroxymethyl) phosphonium sulphate (THPS) inhibition of the biofilm formation was noticed on the carbon steel and thus reduced the CR of about 0.36, 0.46 and 0.42 mm/year. The electrochemical studies also revealed that higher charge transfer resistance (105 Ω cm2) and solution resistance (6.99 Ω cm2) in the presence of THPS due to the intact protective film on carbon steel surface. Thus, THPS is found to act as an effective candidate towards control microbial influenced corrosion by thermophilic bacteria on carbon steel API5LX in a 36% chloride environment.

Enhancing sludge biodegradability and volatile fatty acid production by tetrakis hydroxymethyl phosphonium sulfate pretreatment

A new pretreatment method based on tetrakis hydroxymethyl phosphonium sulfate (THPS) biocide was tried to enhance sludge disintegration, and improved sludge biodegradability and subsequent volatile fatty acid (VFA) production. Sludge activity decreased to less than 10% after 2 days pretreatment using 20mg/g-TSS THPS, which also obviously destroyed EPS and cell membrane, and dissolved more biodegradable substances (48.8%) than raw sludge (19.7%). Moreover, 20mg/g-TSS THPS pretreatment shortened fermentation time to 4days and improved VFA production to 2778mg COD/L (4.35 times than that in control). Therein, the sum of n-butyric, n-valeric and iso-valeric acids unexpectedly accounted for 60.5% of total VFA (only 20.1% of that in control). The more high molecular weight VFAs (C4-C5) than low molecular VFAs (C2-C3) resulted from THPS pretreatment benefited to subsequent medium-chain volatile acids (C6-C12) generation to realize the separation and recovery of organic carbon more efficiently.

Economical and environment-friendly synthesis of a novel hyperbranched poly(aminomethylphosphine oxide-amine) as co-curing agent for simultaneous improvement of fire safety, glass transition temperature and toughness of epoxy resins

Epoxy resins inherently suffer flammability and brittleness. Various approaches have been used to improve their fire safety or toughness, however, glass transition temperature (Tg) is always deteriorated concomitantly. Herein, a novel hyperbranched poly(aminomethylphosphine oxide-amine) (HPAPOA) was synthesized from α-aminomethylation reaction of trihydroxymethylphosphine (THP) with piperazine before oxidation. THP was prepared from tetrakis(hydroxymethyl)phosphonium sulfate and barium hydroxide to avoid complex purification in the synthesized process. When HPAPOA was utilized as co-curing agent for epoxy resins, Tg and impact strength of epoxy thermosets are improved due to the increased cross-linking density and the multiple toughening mechanisms. Simultaneously, fire safety include flame retardancy, smoke suppression and toxicity reduction is raised (except 1.0wt% added). The condensed phase flame retardant mechanism is verified as increased char yield and protective and barrier effect of the formed char layer and the gas phase for release of phosphorus-containing species of HPAPOA. With as low as 3.0wt% HPAPOA incorporated, epoxy thermoset achieved vertical burning V-0 rating with a limited oxygen index of 30.7%. The blowing-out effect for upgradation of vertical burning rating is elucidated. Moreover, the curing reactivity of epoxy systems is slightly changed and the reaction activation energy is elevated. The thermal decomposition temperature of epoxy thermoset diminishes. With 2.0wt% HPAPOA added, tensile and flexural properties are improved and those with other contents are slightly depressed. The practical HPAPOA modified epoxy thermosets with obvious disadvantage conquered and higher Tg can be used in industries for high-performance applications.

Substrate Availability, pH, and Temperature Influence Methanogenesis and Mild Steel Corrosion

ABSTRACTSolid deposits of corroded pipelines in the Niger Delta were analyzed both chemically and microbiologically. The addition of substrate, especially acetate, significantly stimulated the methane production ranging from 0.85 to 1.60 mmole compared with 0.65 mmole of the control. Acetotrophic and hydrogenotrophic methanogens had their optimal methane production and corrosion rate at pH 5.5. All three types of methanogens produced the most methane at 37°C. Methane production by methanogens correlated strongly with corrosion rate. Pyrosequencing surveys show dominance of acetotrophic, hydrogenotrophic, and methylotrophic methanogens in the samples with no significant presence of sulfate-reducing bacteria (SRB), most likely due to the presence of the biocide, tetrakis-hydroxymethyl phosphonium sulfate. Our study shows that methanogens were one possible cause of pipeline failures in samples from the Niger Delta without the syntrophic association with SRB.

Studying the use of tetrakis(hydroxymethyl)phosphonium sulfate (THPS) as zinc sulfide and lead sulfide scales dissolver and the factors influencing the dissolution

Studying the use of tetrakis(hydroxymethyl)phosphonium sulfate (THPS) as zinc sulfide and lead sulfide scales dissolver and the factors influencing the dissolution

The exploration of the effective methods to evaluate the stripping ability of bacteriacide to SRB biofilm

Purpose The purpose of this paper was to study some effective evaluation methods for the biocide performance on sulfate-reducing bacteria (SRB) biofilm. Design/methodology/approach The most probable number method, electrochemical impedance spectroscopy (EIS) measurements, scanning electron microscopy (SEM), three-dimensional (3D) photos and epifluorescent microscopy were used in this study. Findings The results showed that the minimum inhibitory concentrations and minimum bactericidal concentrations of them to sessile SRB were greatly more than planktonic SRB. The EIS of the two biocides indicated that the biofilm exposed to higher concentrations of biocide were much more compact and flat, which perfectly coincided with the SEM, 3D photos and the epifluorescent microscopies. Originality/value In this paper, it, thus, appears that these methods evaluating biocide performance on the SRB biofilm were really effective by comparing the performance of bis-quaternary ammonium salt (BAQS) and tetrakis hydroxymethyl phosphonium sulfate.

Phosphorus-containing polymers from THPS. IV: Synthesis and properties of phosphorus-containing polybenzoxazines as a green route for recycling toxic phosphine (PH3) tail gas

A convenient route to convert the highly toxic phosphine (PH3) tail gas into high-performance polybenzoxazines was first described in this paper. Two aliphatic polyamines, namely tris(aminomethyl)phosphine oxide and bis(aminomethyl)phenylphosphine oxide, were synthesized from tetrakis(hydroxymethyl)phosphonium sulfate (THPS), a green derivative of PH3 tail gas. And then two novel phosphorus-containing benzoxazine monomers, tris(3,4-dihydro-2H-1,3-benzoxazin-3-yl-methyl)phosphine oxide (TBOz) and benzylbis(3,4-dihydro-2H-1,3-benzoxazin-3-yl-methyl) phosphine oxide (BBOz) were prepared by three-steps procedure. FT-IR and DSC technologies were adopted to study the thermal-initiated polymerization behaviors of two benzoxazine monomers. Thermal properties of these crosslinked polymers were studied by TGA and DMA. The results display that the polybenzoxazines (PTBOz and PBBOz) exhibite good thermal stabilities and high glass transition temperatures. The char yield of polybanzoxazine is high as 47% and indiactes that phosphorus-containing polybenzoxazines show high fire-retardancy. The surface free energies of the PTBOz and PBBOz are 37.1 and 40.4mJm−2 by Owens two-liquid method. The dielectric properties of the PTBOz and PBBOz remaine near constant in the experimental frequency range.

Evaluation of sludge reduction of three metabolic uncouplers in laboratory-scale anaerobic–anoxic–oxic process

To evaluate the sludge reduction of three metabolic uncouplers (3,3′,4′,5-tetrachlorosalicylanilide (TCS), 2,4-dichlorophenol (DCP), and tetrakis (hydroxymethyl) phosphonium sulfate (THPS)), we conducted continuous experiments on laboratory-scale anaerobic–anoxic–oxic processes. The three metabolic uncouplers were separately added in each oxic tank of the three systems, and a system without uncoupler addition was used as control. During the 85-day operation, sludge production and observed growth yields decreased to 38.6% and 16.98%, 43.4% and 17.55%, and 39.3% and 17.04% by the addition of TCS, DCP, and THPS, respectively. The addition of metabolic uncouplers slightly reduced the wastewater treatment efficiencies of the system (about 1.1–8.7%) and increased sludge SVIs (about 69.9–80.6%). Meanwhile, the differences among three metabolic uncouplers were little. Besides metabolic uncoupling and maintenance metabolism, which exist in the TCS- and DCP-added systems, lysis–cryptic growth also exists in the THPS-added system.

The effects of Tetrakis-hydroxymethyl phosphonium sulfate (THPS), nitrite and sodium chloride on methanogenesis and corrosion rates by methanogen populations of corroded pipelines

The effects of some biocides on methanogens associated with pipeline corrosions were investigated. The crude oil transporting pipeline showed higher methane production (60%) and corrosion rates (42%) than the water transporting pipeline. Higher concentrations of biocide (0.7% Tetrakis-hydroxymethyl phosphonium sulfate) and 40mM nitrite were required for both pipelines to sufficiently inhibit methanogenesis and corrosion rates. A sudden increase in corrosion rate happened only in samples that produced higher than 1.5mmole of methane. Pyrosequencing surveys shows dominance of acetotrophic, hydrogenotrophic and methylotrophic methanogens in the samples. The methane productions and corrosion rates were strongly correlated under all the conditions.

Synthesis of 1-substituted 2,6,7-trioxa-4-phospha-1-borabicyclo[2.2.2]octan-1-uide

ABSTRACT1-Substituted 2,6,7-trioxa-4-phospha-1-borabicyclo[2.2.2]octan-1-uides were obtained in 31–71% yields by the reaction of tetrakis(hydroxymethyl)phosphonium sulfate with alkyl- or arylboronic acids in the presence of tetrabutylammonium hydroxide.

Metabolic Capability of a Predominant Halanaerobium sp. in Hydraulically Fractured Gas Wells and Its Implication in Pipeline Corrosion.

Microbial activity associated with produced water from hydraulic fracturing operations can lead to gas souring and corrosion of carbon-steel equipment. We examined the microbial ecology of produced water and the prospective role of the prevalent microorganisms in corrosion in a gas production field in the Barnett Shale. The microbial community was mainly composed of halophilic, sulfidogenic bacteria within the order Halanaerobiales, which reflected the geochemical conditions of highly saline water containing sulfur species (S2O32-, SO42-, and HS-). A predominant, halophilic bacterium (strain DL-01) was subsequently isolated and identified as belonging to the genus Halanaerobium. The isolate could degrade guar gum, a polysaccharide polymer used in fracture fluids, to produce acetate and sulfide in a 10% NaCl medium at 37°C when thiosulfate was available. To mitigate potential deleterious effects of sulfide and acetate, a quaternary ammonium compound was found to be an efficient biocide in inhibiting the growth and metabolic activity of strain DL-01 relative to glutaraldehyde and tetrakis (hydroxymethyl) phosphonium sulfate. Collectively, our findings suggest that predominant halophiles associated with unconventional shale gas extraction could proliferate and produce sulfide and acetate from the metabolism of polysaccharides used in hydraulic fracturing fluids. These metabolic products might be returned to the surface and transported in pipelines to cause pitting corrosion in downstream infrastructure.

Enhanced Biocide Mitigation of Field Biofilm Consortia by a Mixture of D-Amino Acids.

Microbiologically influenced corrosion (MIC) is a major problem in the oil and gas industry as well as in many other industries. Current treatment methods rely mostly on pigging and biocide dosing. Biocide resistance is a growing concern. Thus, it is desirable to use biocide enhancers to improve the efficacy of existing biocides. D-Amino acids are naturally occurring. Our previous work demonstrated that some D-amino acids are biocide enhancers. Under a biocide stress of 50 ppm (w/w) hydroxymethyl phosphonium sulfate (THPS) biocide, 1 ppm D-tyrosine and 100 ppm D-methionine used separately successfully mitigated the Desulfovibrio vulgaris biofilm on carbon steel coupons. The data reported in this work revealed that 50 ppm of an equimolar mixture of D-methionine, D-tyrosine, D-leucine, and D-tryptophan greatly enhanced 50 ppm THPS biocide treatment of two recalcitrant biofilm consortia containing sulfate reducing bacteria (SRB), nitrate reducing bacteria (NRB), and fermentative bacteria, etc., from oil-field operations. The data also indicated that individual D-amino acids were inadequate for the biofilm consortia.

Mitigation of microbially influenced corrosion of Cu–Ni (90/10) alloy in a seawater environment

In industries where a heat exchanger is made up of Cu–Ni (90/10) alloy and seawater is used as a coolant, microbially influenced corrosion (MIC) is a serious problem. MIC of Cu–Ni (90/10) alloy in a seawater environment inoculated with sulfate-reducing bacteria was successfully inhibited by using two different inhibitor formulations viz. (1) 1,2,3-benzotriazole (BTAH) + tetrakis(hydroxymethyl)phosphonium sulfate (THPS) and (2) 5-(3-aminophenyl)tetrazole + THPS. Electrochemical impedance and potentiodynamic polarization studies showed an inhibition efficiency greater than 99 % for both formulations. The inhibitor formulation BTAH + THPS is so effective that in its presence, there is total absence of any MIC and microfouling even after 90 days, as evidenced by scanning electron micrographs and microbial count.

Phosphorus-containing polymers from THPS. VII. Synthesis of phosphorus-containing trialkynes and their metal-free 1,3-dipolar cycloaddition reaction with azidated soybean-oil

A novel hydrolysis-resistant trialkyne, namely tris(prop-2-yn-1-yloxy methyl)phosphane oxide (TPOPO), was prepared from an environmentally friendly tetrakis(hydroxymethyl)phosphonium sulfate (THPS).

Synthesis of a novel cross‐linked organophosphorus‐nitrogen containing polymer and its application in flame retardant epoxy resins

SummaryA novel cross‐linked organophosphorus–nitrogen polymetric flame retardant additive poly(urea tetramethylene phosphonium sulfate) defined as PUTMPS was synthesized by the condensation polymerization between urea and tetrahydroxymethyl phosphonium sulfate. Its chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy, 13C and 31P solid‐state nuclear magnetic resonance. The synthesized PUTMPS and curing agent m‐phenylenediamine were blended into epoxy resins to prepare flame retardant epoxy resin thermosets. The effects of PUTMPS on fire retardancy and thermal degradation behavior of EP/PUTMPS thermosets were investigated by limiting oxygen index (LOI), vertical burning test (UL‐94), cone calorimeter measurement, and thermalgravimetric analysis (TGA) tests. The surface morphologies and chemical compositions of char residues for cured epoxy resins were investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy (XPS), respectively. Water resistant properties of epoxy resin thermosets were evaluated by putting the samples into distilled water at 70°C for 168 h. The results demonstrated that the EP/12 wt% PUTMPS thermosets successfully passed UL‐94 V‐0 flammability rating and the LOI value reached 31.3%. The TGA results indicated that the incorporation of PUTMPS promoted epoxy resin matrix decomposed and char forming ahead of time, which led to a higher char yield and thermal stability for epoxy resin thermosets at high temperature. The morphological structures and analysis of XPS for the char residues of the epoxy resin thermosets shown that PUTMPS benefited to the formation of a sufficient, more compact, and homogeneous char layer with rich flame retardant elements on the materials surface during burning, which prevented the heat transmission and diffusion, limited the production of combustible gases, inhibited the emission of smoke, and then led to the reduction of the heat release rate and smoke produce rate. After water resistance tests, EP/12 wt% PUTMPS thermosets still remained excellent flame retardancy. Copyright © 2015 John Wiley & Sons, Ltd.

A Comparison of Three Nonoxidizing Biocides and Chlorine Dioxide in Treating Marcellus Shale Production Waters

Summary Chlorine dioxide (ClO2), a relative new addition to the oil and gas fracturing industry (especially for production-water treatment for reuse), has superior microbial efficacy compared with currently used nonoxidizing biocides at their lowest and mid-range US Environmental Protection Agency approved concentrations. ClO2 is the only antimicrobial treatment to exhibit complete kill of any of the bacterial populations [except tetrakishydroxymethyl phosphonium sulfate (THPS) at 208 ppm (commodity basis) in 100% Marcellus shale production water], and demonstrated greater than 5.16 log10 reduction even at the lowest ClO2 residual tested (i.e., 1.19 ppm residual; 9 ppm dose). As a result, ClO2 should be considered a potentially viable option when selecting a biocide for treating fracturing production waters for reuse in the Marcellus shale play.

Synthesis of a cross-linked triazine phosphine polymer and its effect on fire retardancy, thermal degradation and moisture resistance of epoxy resins

A novel cross-linked triazine phosphine polymeric flame retardant additive polymelamine tetramethylene phosphonium sulfate defined as PMTMPS was synthesized by the condensation polymerization between melamine and tetrahydroxymethyl phosphonium sulfate. Its chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy, 13C and 31P solid-state nuclear magnetic resonance. The synthesized PMTMPS and curing agent m-phenylenediamine were blended into epoxy resins to prepare flame retardant epoxy resins thermosets. The effects of PMTMPS on fire retardancy and thermal degradation behavior of the cured EP/PMTMPS composites were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimeter measurement (cone) and thermogravimetric analysis (TGA) tests. The morphologies and chemical compositions of char residues for cured epoxy resins were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Moisture resistant properties of epoxy resins thermosets were evaluated by putting the samples into distilled water at 70 °C for 168 h. The results demonstrated that the cured EP/11 wt % PMTMPS composites successfully passed UL-94 V-0 flammability rating and the LOI value was as high as 32.5%. The TGA results indicated that the incorporation of PMTMPS stimulated epoxy resins matrix decomposed and char forming ahead of time, which led to a higher char yield and thermal stability for epoxy resins thermosets at high temperature. The morphological structures and the analysis results of XPS for char residues of thermosets revealed that the introduction of PMTMPS benefited to the formation of a sufficient, more compact and homogeneous char layer with rich flame retardant elements on the materials surface during burning, which prevented the heat transmission and diffusion, limited the production of combustible gases, inhibited the emission of smoke and then led to the reduction of the heat release rate and smoke produce rate. The results of water resistance tests shown the moisture absorption of EP/PMTMPS thermosets was lower than that of pure epoxy resins thermosets and the samples still remained excellent flame retardancy after water resistance tests.