Trioctyl Phosphate Research Articles

Domain size of dynamic heterogeneities in antiplasticized polycarbonate by proton spin diffusion

AbstractProton spin diffusion measurements were made using the Goldman—Shen technique of bisphenol‐A polycarbonate containing 10 wt% trioctyl phosphate at temperatures below the glass transition temperature. The proton lineshapes reveal the existence of dynamic heterogeneities in the glass and spin diffusion can be observed from the more mobile to the less mobile domain. The time‐scale for spin diffusion is 4–10 ms and the mobile domain size is estimated at 11 Å at 339 K. This estimate is consistent with a mobile domain of approximately two diluent molecules and 11 polymer repeat units. This grouping can be compared with the results of a statistical lattice model used to estimate local environments at this composition.

Evaluation of an ammonium ionophore for use in poly(vinyl chloride) membrane ion-selective electrodes: solvent mediator effects.

A macrotetrolide nonactin-based ammonium ionophore (AI) preparation containing 25% nonactin optimized for use in liquid membrane ion-selective electrodes was investigated for its possible use in poly(vinyl chloride) (PVC) matrix membrane-type electrodes. Nine different plasticizing solvent mediators were employed in the ammonium ion-selective membranes with PVC and the AI preparation. Near Nernstian responses were observed in aqueous solution with electrodes fabricated with dioctyl sebacate-, 2-nitrophenyl phenyl ether-, dibutyl sebacate-, trioctyl phosphate-, dioctyl adipate-, dioctyl phenyl phosphonate- and 2-nitrophenyl octyl ether-plasticized membranes. The responses of these electrodes were found to improve in the presence of a background concentration of non-interfering calcium ions.

Poly(vinyl chloride) type ammonium ion-selective electrodes based on nonactin: solvent mediator effects

This communication describes poly(vinyl chloride) ammonium ion-selective electrodes based on nonactin and focuses on 2-nitrophenyl octyl ether and trioctyl phosphate as solvent mediators; such ion selective electrodes do not require the use of a buffer trap as in the DOA plasticized system.

Photochemical behavior of organic phosphate esters in aqueous solutions irradiated with a mercury lamp.

Pollution by toxic chemicals that are resistant to biological degradation and have a potential for accumulation in biological organisms is becoming a world-wide problem. Organic phosphate esters (OPEs) are widely used as plasticizers, industrial hydraulic fluids, and lubricant additives. Various OPEs have been detected in environmental samples and in industrial and domestic wastewaters. Ultraviolet (UV) irradiation is known as an effective treatment for persistent chemicals in natural water or wastewater. Therefore, in order to develop a means of removal of OPEs in water, some fundamental experiments with UV irradiation were performed with a mercury lamp, and photochemical behaviors and photodecomposition products were examined for 7 OPEs, namely tributyl phosphate(TBP), tris(chloropropyl) phosphate (TCPP), tris(2-chloroethyl) phosphate (TCEP), trioctyl phosphate (TOP), tris(dichloropropyl) phosphate (CRP), triphenyl phosphate (TPP), and tricresyl phosphate (TCP). 12 refs., 2 figs., 1 tab.

Chloroquine polymeric membrane electrodes: Development and applications

Three main types of PVC solvent polymeric membrane ion-selective electrodes for chloroquine are described. They are based on three ion-pairing agents namely dipicrylamine (DPA), tetraphenylborate (TPB) or tetrakis(4-chlorophenyl)borate (TCPB) with either dioctylphenyl phosphonate (DOPP) or trioctyl phosphate (TOP) solvent mediator. All electrodes exhibit Nernstian responses, fast dynamic response times and a wide useful pH range. The best all-round electrode is based on TPB and TOP plasticizing solvent mediators with a limit of detection of 7.1 × 10 −6 M and was utilized for the assay of chloroquine in tablets. Direct potentiometric determinations with either the analyte addition method or the normal calibration method gave results comparable to the official method.

Mobility and the Glass Transition in Mixed Polymer-Diluent Glasses by NMR

AbstractPhosphorous and proton line shape studies of a trioctyl phosphate diluent in polycarbonate and in a fifty-fifty blend of polystyrene with polyphenylene oxide have been performed to monitor diluent dynamics. Both the phosphorous and proton line shapes are superficially bimodal with a narrow, mobile component of the line shape appearing at temperatures well below the thermal glass transition temperatures. Plots of the h.ction of mobile material versus temperature show two step increases separated by a plateau region. This behavior is analyzed in terms of a distribution of activation energies which results in a bimodal description. The bimodal activation energy distribution corresponds to a bimodal correlation time distribution. The more mobile material is identified with diluent molecules in contact with other diluent molecules in a lattice description which assumes a single phase system is assumed with a purely random distribution of diluent and polymer on the lattice.

Decontamination of Nitrate Polluted Water

Abstract Nitrate can be extracted from water at any pH below 10 by a water-insoluble quaternary ammonium 2, 4, 6-tri-methylphenate or N-benzyl-H-methylbenzenesulfonamidate dissolved in trioctylphosphate (TOP). Membranes were prepared by taking up TOP solutions of the quaternary ammonium bases in porous polypropylene (CelgardR-2400). These membranes were used in a modified dialysis cell to transfer N03 − from near-neutral water to stripping solutions of pH, 12–14. Specific rate constants, k, in excess of 10−4 cm s−1 were observed for nitrate removal under a wide variety of loading and stripping conditions. This is sufficient to project a practical device for the decontamination of nitrate-polluted water. When the hydrodynamic resistances in both the feed and the strip are removed by pumping these solutions through static mixers adjacent to the membrane, K is reduced by making the stripping solution less basic or by increasing its nitrate concentration. These observations suggest that the disassembly of the carrier of the N03 − and H+ at the stripping interface is a step-wise process, involving energetically unfavorable, charge-separated species.

Epoxy-based all-solid-state poly(vinyl chloride) matrix membrane calcium ion-selective microelectrodes

Calcium ion-selective microelectrodes have been constructed from PVC matrix membranes containing a calcium bis{di[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphate} electroactive component with dioctyl phenylphosphonate, tripentyl phosphate or trioctyl phosphate as a plasticising solvent mediator, and from the Philips IS 561/SP membrane. The electrode membranes are backed with a silver-based conductive epoxy implanted with a copper wire for electrical contact. Of the three types of electrodes designed, namely, glass capillaries with a pre-formed membrane (type A) or an applied membrane (type B) and infrared heat-drawn Perspex capillaries with applied membrane (type C), the most functional are types B and C, which have functional lifetimes of 6 and 10 d, respectively.The electrodes have tip diameters of 1–3 µm for glass and 5–10 µm for Perspex, the bevelled tip in the latter ensuring a sharp edge.

Studies of calcium ion-selective electrodes in the presence of biochemical materials

Interferences by biochemical materials of responses towards calcium ions of calcium ion-selective electrodes have been studied for PVC matrix membrane electrodes based on calcium bis{di[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphate} sensor with dioctyl phenylphosphonate (I), tripentyl phosphate (II) or trioctyl phosphate (III) as solvent mediator. Experiments have also been carried out on electrodes made from commercial calcium ion-selective electrode membranes based on an ionophore sensor (electrode IV). E. m.f. changes of <0.5 mV were observed for up to 10–3M starch, sucrose, uric acid, creatinine and bilirubin. Larger e.m.f. changes were observed for cholic acid, cholesterol, lecithin and vitamin D2(each of which were tested as solutions in ethanol or propan-1-ol added to the calcium ion containing solution in water or 0.15 M sodium chloride solution). Electrode III showed the greatest resistances to interferences by the biochemical components, followed by electrode IV. Interferences by urea and glucose were less than 1 mV for electrodes I-III and slightly more for electrode IV.

Flow injection analysis with tubular membrane ion-selective electrodes in the presence of anionic surfactants

Calcium ion-selective electrodes based on calcium bis{di[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphate} with trioctyl phosphate in poly(vinyl chloride) have improved resistance to interference by anionic surfactants when used in flow injection analysis. Tubular membrane electrodes have been used in flow injection analysis for determining calcium ion levels in selected potable and raw water and the data agree well with determinations by atomic-absorption spectroscopy and EDTA titration.

Studies of calcium ion-selective electrodes in the presence of anionic surfactants

Eighteen membrane systems, based on a calcium bis{di[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphate} ion sensor have been compared in potentiometric studies with a membrane based on the sensor with a dioctyl phenylphosphonate solvent mediator with respect to interferences of calcium ion-selective electrodes by anionic surfactants, especially by sodium dodecylsulphate (SDS) and sodium tetradecylbenzenesulphonates (ABS). Electrodes made from poly(vinyl chloride) matrix membranes of the sensor with trioctyl phosphate solvent mediator are far superior to the other membrane systems in resisting interference by anionic surfactants and are shown to yield calcium ion levels in the presence of a wash liquor to match the expected values.Some improvement over dioctyl phenylphosphonate is also offered by decan-1-ol, dodecan-1-ol and tetradecan-1-ol but the use of such solvent mediators impairs calcium ion selectivity and poly(vinyl chloride) plasticising qualities. The use of alternative polymer matrices based on poly(vinylidene chloride) and VAGH copolymer (hydrolysed vinyl chloride - vinyl acetate) offer no advantages.A nineteenth membrane, obtained from a commercial supplier, exhibited interference by SDS.An interesting effect is the increase (rather than the normal decrease) in e.m.f. observed for those electrodes from membranes in which the amount of free active sensor was reduced to low levels. By using optimum levels of sensor it was possible to fabricate electrodes exhibiting a zero e.m.f. change when changing the background 10–2M calcium chloride to one that is also 10–3M is SDS. Such membranes are based on decyl phosphate grafted to VAGH copolymer.X-ray fluorescence and chromatographic studies on membranes of the sensor with dioctyl phenylphosphonate in poly(vinyl chloride) show SDS to be a significant agent in leaching membrane components, especially of dioctyl phenylphosphonate. Such observations are indicative that the interference of calcium ion-selective electrodes by anionic surfactants may be the result of the different solubilities of calcium - surfactant complexes in the solvent mediator of the membrane.

Toxicity of several phosphoric acid esters in rats

JCL-Wistar male rats were fed a diet containing 0 or 0.5% of trimethyl phosphate (TMP), triethyl phosphate (TEP), tri- n-butyl phosphate (TBP), trioctyl phosphate (TOP), or tricresyl phosphate (TCP) for 9 weeks. Body weights in TMP- and TBP-treated rats were significantly lower than the control. No differences in toxicity were observed among the test compounds, although there were differences between the treated and control rats in some organ weights, hematological values and serum components.

The effect of the addition of phosphate esters to paraffinic base oils on their lubricating performance under sliding conditions

Using a modified Timken machine, the effect of the addition of different phosphate esters to paraffinic base oils on their lubricating performance was investigated. The aryl phosphate ester tricresyl phosphate (TCP) has a greater resistance to scuffing than the alkyl phosphate ester trioctyl phosphate (TOP) when used as a lubricant. In contrast, base oils containing TOP are superior to those containing TCP, although phosphate esters are effective only in base oils of higher viscosity than the esters. The lubricating performance of high viscosity base oils containing TOP is improved by coupling the ability of TOP to form a beneficial surface film with the ability of the base oils to build up thick oil films. The addition of TCP, which has a higher adsorption ability but a lower reactivity than TOP, seems, however, to prevent the formation of the oxide film which is formed with base oils alone owing to the marked ability of TCP to adhere to a metal surface. In addition, because of the low reactivity of TCP, iron phosphate is hardly formed. Consequently, the addition of TCP increases the scuffing load of the base oils but has the disadvantage of increasing the coefficient of friction.

環境水中における有機りん酸エステル類の減衰

Environmental fate in river and sea water was studied for 6 organic phosphate esters; tributyl phosphate (TBP), tris (butoxyethyl) phosphate (TBXP), trioctyl phosphate (TOP), tricresyl phosphate (TCP), triphenyl phosphate (TPP), and tris (dichloropropyl) phosphate (CRP). In the river waters, the degradation rates of TPP and TCP, both having phenyl ester groups were faster than those of other phosphate esters. The rates of the phosphate esters having liner alkyl ester groups such as TBP, TBXP, and TOP, were faster as the length of alkyl chain become shorter. The rate of CRP which has chlorine atoms was much slower. The decay characteristics in the polluted sea water was similar to that in the river water. Moreover, the degradation rates in the clean sea water were much slower.

Effect of different phosphate esters on frictional characteristics

In this paper, tricresyl phosphate (TCP), an aryl phosphate, and trioctyl phosphate (TOP), an alkyl phosphate, were used in corrosion and four ball tests to determine their respective frictional characteristics. TOP was found to be advantageous under conditions of mild lubrication due to its high reactivity, but was unable to prevent scuffing at high temperature or high contact load. TCP, however, was found to form, under high friction, films of high mechanical and thermal strengh

Soil Burial Tests: Trends in Material Behavior After Eight Years of Soil Exposure

The preceding papers have presented detailed coverage of soil burial effects on specific classes of organic materials. This paper summarizes some of the trends which have emerged in the eight years of soil exposure in both acid and alkaline soil: (i) High-density and black crosslinked polyethylenes, rigid PVCs, acrylics, polycarbonates, acetates, fluorocarbons, styrene polyesters, unfilled epoxy, neoprene without clay, and sulfur-cured nitrile rubber have been essentially unaffected. (ii) Insect attack is confined to the soft forms of materials such as cellulosics, rubbers, and thermoplastics, specifically low-density polyethylene and certain plasticized poly(vinyl chloride) samples. All cast resins, structural laminates, and hard thermosetting plastics have been completely free of insect attack. (iii) With both plastics and elastomers, significant losses in tensile strength are almost always accompanied by large decreases in insulation resistance. (iv) Some plastic materials tend to increase in tensile strength due to the loss of constituents while some lose strength because of chemical breakdown. The reinforced thermosetting materials decrease in strength because of moisture penetration along the resin-fiber bond. (v) Of the plasticized PVC wire insulations, the materials with trioctyl and octyl diphenyl phosphate, and dioctyl adipate blend, have shown significant increases in modulus indicative of plasticizer loss due to teaching and/or microbial consumption.

CS in Trioctyl Phosphate: Effects on Human Eyes

CS in Trioctyl Phosphate: Effects on Human Eyes

The Reaction of Ozone with SBR Rubbers

Abstract All SBR vulcanizates, when tested in a relaxed state, reacted with ozone of low concentrations to form a film of oxidized products which provided an effective barrier against further attack by gaseous ozone. SBR vulcanizates that were under stress, but which contained no effective antiozonant in their formulation, were readily attacked by ozone. The absorption of ozone appeared to begin with an initial rate of zero which was followed by rapidly increasing rates until a maximum had been reached, when ozone cracks were visible on the surface of the rubber. SBR vulcanizates that were under stress, but which contained an antiozonant, were protected from an attack by ozone to a degree that ranged from poor to excellent. The degree of protection depended (a) on the differential in the rates of reaction of the antiozonant and the rubber hydrocarbon with ozone, (b) on the initial concentration of the antiozonant on the surface of the vulcanizate which reacted with ozone to form a barrier of oxidized residues, and (c) on the rate of effusion of fresh antiozonant from within the rubber to the outer surface of the barrier. SBR vulcanizates containing a naphthenic processing oil as an extender were not so resistant to ozone as standard SBR vulcanizates. It is probable that the effectiveness of the antiozonants tested in these vulcanizates was reduced by their high solubility in the oil phase. SBR vulcanizates containing trioctyl phosphate as a plasticizer were vigorously attacked by ozone. It is possible that the gaseous ozone dissolved to some extent into the plasticizer phase, increasing the concentration of ozone in the area causing a more severe oxidation of the rubber. SBR vulcanizates that had been coated with an antiozonant by dipping the specimen several times into a solution of the antiozonant in a solvent were found to contain a higher concentration of the antioxonant directly on the surface of the vulcanizate than in the case where three parts of the antiozonant were added during vulcanization. A mechanism for the ozonization of SBR vulcanizates has been proposed which includes a possible mechanism for the protective action of antiozonants. A rate equation has been derived from this mechanism which was consistent with the experimental rate data.

Creep behavior of plasticized vinylite VYNW

AbstractThe viscoelastic properties of plasticized Vinylite VYNW were studied over a wide range of time scale by means of the tensile creep test. A number of different plasticizers were compared as to their plasticizing effectiveness. It was found that different plasticizers imparted distinctly different shapes to the creep curve of the plasticized ferent plasticized resin. The flat creep curve, characteristic of trioctyl phosphate, is considered to be superior to the steep creep curve of tricresyl phosphate. Mixtures of plasticizers were also studied. A number of conjectures are advanced concerning the molecular mechanism of plasticizer action. One important characteristic of a plasticized formulation of the polyvinyl chloride types of resin is the existence of a three‐dimensional gel structure of great permanence which prevents the occurrence of irrecoverable viscous flow.