Methyl Phosphine Oxide Research Articles

Development of novel phosphorus‐containing epoxy resins from renewable resources

AbstractNovel biobased epoxy resins were prepared from two fatty acid derivatives; epoxidized 10‐undecenoyl triglyceride and epoxidized methyl 3,4,5‐tris(10‐undecenoyloxy)benzoate, with 4,4′‐diaminodiphenylmethane as a crosslinking agent. The flame retardancy of these epoxy resins was improved by the addition of 10‐[2′, 5′‐bis(9‐oxiranyl‐nonayloxy)phenyl]‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and by crosslinking with a phosphorus‐containing curing agent, bis(m‐aminophenyl)methylphosphine oxide. The thermal, thermomechanical, and flame‐retardant properties of the cured materials were measured with differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, and the limiting oxygen index. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6717–6727, 2006

Synthesis and properties of thermosetting polymers from a phosphorous‐containing fatty acid derivative

AbstractA new phosphorous‐containing fatty acid diepoxide was obtained from 10‐undecenoyl chloride and 10‐(2′,5′‐dihydroxyphenyl)‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and crosslinked with 4,4′‐diaminodiphenylmethane and bis(m‐aminophenyl)methylphosphine oxide. The properties of the thermosetting materials were evaluated by differential scanning calorimetry, dynamic mechanical thermal analysis, thermogravimetric analysis, and limiting oxygen index (LOI). Thermal and thermooxidative degradation was studied by gas chromatography/mass spectrometry, FTIR, 31P magic angle spinning NMR spectroscopy, and scanning electron microscopy. LOI values indicate good flame‐retardant properties that are related to the formation of a protective phosphorous‐rich layer that slowed down the degradation and prevented it from being total. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5630–5644, 2006

Magnetic Carrier for Radionuclide Removal from Aqueous Wastes: Parameters Investigated in the Development of Nanoscale Magnetite Based Carbamoyl Methyl Phosphine Oxide

A study on superparamagnetic magnetite polymer composite development was undertaken for application to magnetically assisted chemical separation. Tetramethyl ammonium hydroxide as an alternative to ammonia was used as a precipitation agent to obtain nanoscale magnetite particles. Investigation on stoichiometry control of Fe(III) and Fe(II) ions suggested a correlation between alkalinity and initial Fe(III): Fe(II) ratio for precipitation of magnetite. Studies on polymerization conditions suggested that polymers setting at ambient conditions enable retention of superparamagnetic property of substrate magnetite. Vaporization method for impregnation of solvent extractant CMPO, yielded product that had a high sorption capability for radionuclide europium as compared to wet impregnation method.

Curing studies of epoxy resins with phosphorus‐containing amines

AbstractThe curing system of diglycidyl ether of bisphenol A (DGEBA) with two phosphorus‐containing amine compounds—bis(3‐aminophenyl)methyl phosphine oxide and bis(4‐aminophenyl)‐bis(9,10‐dihydro‐9‐oxa‐10‐oxide‐10‐phosphaphenanthrene‐10‐yl)methane—was studied with differential scanning calorimetry under isothermal and nonisothermal conditions and compared with the DGEBA/diamino diphenyl methane system. The isoconversional method was used to evaluate the dependence of the effective activation energy on the extent of conversion. Modulated differential scanning calorimetry and dynamic mechanical thermal analysis were used to study the phenomena of vitrification and gelation. The thermal and flame‐retardant properties were evaluated, and the limiting oxygen index values of the phosphorylated resins, above 30, confirmed that phosphorus‐containing epoxy resins are effective flame retardants. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1676–1685, 2006

An ab initio study of the structure and methyl rotational barriers of methylphosphonic dihalides

The molecular structure and the barriers to methyl rotation of symmetric methylphosphonic dihalides (CH 3POX 2, X=F, Cl, Br) and of the corresponding non-halogenated molecule (methyl phosphine oxide, X=H) were determined through ab initio calculations at the MP2/6-31+G(2d,p) level. The four molecules adopt the staggered conformation, with skeletal angles decreasing in the order OPC ˆ > OPX ˆ > XPC ˆ > XPX ˆ . The strong electron-withdrawing effect of the halogen atoms decreases the electron density on the oxygen atom, and increases the double bond character of the phosphoryl group. This, in turn, leads to an increase of the hyperconjugative interactions between this group and the two C–H bonds lying out of the OPC plane, and results in a slight lengthening of these bonds relative to the in-plane C–H bond. Methyl rotations were followed by means of intrinsic reaction coordinate calculations (IRC), and the calculated energy barriers were 1.61, 2.41, 2.77 kcal/mol for the difluoride, dichloride and dibromide, respectively, and 2.01 kcal/mol for methyl phosphine oxide. Structural evidences suggest that hyperconjugation stabilizes the transition structure for methyl rotation in the difluoride molecule, which explains the comparatively low value of its rotational barrier.

Curing and thermal behavior of diglycidyl ether of bisphenol A in the presence of a mixture of amines

AbstractThe curing behavior of diglycidyl ether of bisphenol A (DGEBA) was investigated by differential scanning calorimetry with mixtures of silicon‐containing amide–amines and diaminodiphenyl sulfone (DDS). Silicon‐containing amide–amines were prepared by the reaction of 2.5 mol of 4,4′‐diaminodiphenyl ether (E), 4,4′‐diaminodiphenyl methane (M), 3,3′‐diaminodiphenyl sulfone (mS), 4,4′‐diaminodiphenyl sulfone (pS), bis(3‐aminophenyl) methyl phosphine oxide (B), or tris(3‐aminophenyl) phosphine oxide (T) with 1 mol of bis(4‐chlorobenzoyl) dimethyl silane. Mixtures of the amide–amines and DDS at ratios of 0:1, 0.25:0.75, 0.5:0.5, 0.75:0.25, and 1:0 were used to investigate the curing behavior of DGEBA. A single exotherm was observed on curing with a mixture of amide–amine and DDS. This clearly shows that the mixture participated in the cocuring reaction. The peak exotherm temperature depended on the structure and the molar ratio of amide–amines. With all of the amide–amines and DDS, a significant decrease in the kick‐off temperature of the curing exotherm was observed on the incorporation of a 0.25 molar fraction of amide–amines. Thus, with the mixture, the curing temperatures were reduced and were lowest for ether‐containing amide‐amines and highest for methylene‐containing amide–amines. The char yield was almost similar in the samples cured with amide–amines (E, pS, or mS) or DDS. The char yield was higher than for either of the constituents when a mixture was used. A synergistic behavior was observed when a mixture of E, M, mS, or pS and DDS was used, whereas mixture of B or T and DDS showed antigonism in the char yield. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1739–1747, 2003

Phosphorylated Epoxy Resin: Effect of Phosphorus Content on the Properties of Laminates

The paper describes the properties of glass-fabric reinforced composites based on novel phosphorylated epoxy matrix resins. Limiting oxygen index as high as 80 were attained using such novel matrix resins. These resins were prepared by curing diglycidyl ether of bisphenol-A (DGEBA) with phosphorylated amines such as bis(3-aminophenyl) methyl phosphine oxide (B), tris(3-aminophenyl)phosphine oxide (T), bis[3(3′-aminobenzamidophenyl)]-methylphosphine oxide (MB), bis[3(4′-aminobenzamido phenyl)]methylphosphine oxide (PB), tris[3(3′-aminobenzamidophenyl)]phosphine oxide (MT) and tris[3(4′-aminobenzamido phenyl)] phosphine oxide (PT). Phosphorus- containing amide-acid amines were also used for curing and were prepared by reacting T with 1,2,4,5-benzenetetracarboxylic acid anhydride(P); 3,3′,4,4′-benzophenonetetracarboxylic acid dianhydride (Z) and 4,4′-(hexafluoroisopropylidene)diphthalic acid anhydride (F). Interlaminar shear strength (ILSS), flexural strength and modulus of composites (32 ± 3% resin content) based on B, T, MB, PB, MT, PT and state-of-the-art curing agent 4,4′-diaminodiphenyl sulfone (D) were higher than the composites prepared using amide-acid amines. Increase in ILSS was observed on heating at 180°C for 200 h. On hygrothermal ageing of the samples for 7 days, the ILSS values decreased but those cured with amide-acid amines showed the least change. A significant improvement in limiting oxygen index (LOI) was observed by increasing the phosphorus content of the composites.

Studies on the curing kinetics of epoxy resins using silicon containing amide-amines

Curing kinetics of diglycidyl ether of bisphenol-A (DGEBA) in the presence of novel silicon containing amide-amines were investigated by the dynamic differential scanning calorimetry. Silicon containing amide-amines were prepared by reacting 2.5 moles of 4,4'-diaminodiphenyl ether (E)/4,4'-diaminodiphenyl methane (M)/3,3'-diaminodiphenyl sulfone (mS)/bis(m-aminophenyl) methyl phosphine oxide (B) with one mole of bis(4-chlorobenzoyl) dimethyl silane. The multiple heating rate method (5, 10, 15 and 20°C min-1) was used to study the curing kinetics of epoxy resins in the presence of stoichiometric amounts of amide-amines having molecular masses in the range of 660 to 760 g mol-1. The peak exotherm temperature depends on the heating rate as well as on the structure of amide-amines. Activation energy of curing reaction as determined in accordance to the Ozawa's method was found to be dependent on the structure of amine. The thermal stability of the isothermally cured resins was also evaluated using dynamic thermogravimetry in a nitrogen atmosphere. The char yield was the highest in case of resins cured with amide-amines having both phosphorus and silicon atoms.

Curing and thermal behavior of epoxy resin in the presence of silicon‐containing amide amines

AbstractThe article describes the synthesis and characterization of silicon‐containing amide amines obtained by the reaction of bis(4‐chlorobenzoyl)dimethylsilane with 4,4′‐diaminodiphenyl ether, 4,4′‐diaminodiphenyl methane, 4,4′‐diaminodiphenyl sulfone/3,3′‐diaminodiphenyl sulfone, bis(3‐aminophenyl)methyl phosphine oxide, and tris(3‐aminophenyl)phosphine oxide with dimethyl acetamide as a solvent. Structural characterization of amide amines was done with Fourier transform infrared and 1H‐NMR spectroscopy. We used these aromatic amide amines as curing agents to investigate the effect of structure and molecular size on the curing and thermal behavior of diglycidyl ether of bisphenol A (DGEBA). The curing behavior of DGEBA in the presence of stoichiometric amounts of silicon‐containing aromatic amide amines was investigated by differential canning calorimetry. A broad exothermic transition in the temperature range of 200–300°C was observed in all the samples. The peak exotherm temperature was lowest in the case of phosphorus‐containing amides and was highest in the case of ether‐containing amides. Thermal stability of the isothermally cured resins was evaluated with dynamic thermogravimetry in a nitrogen atmosphere. A significant improvement in the char yield was observed with silicon‐containing amines, and it was highest in case of samples with both silicon and phosphorus as flame‐retarding elements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1345–1353, 2003

Phosphorus‐containing epoxy resins: Thermal characterization

AbstractThree novel aromatic phosphorylated diamines, i.e., bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl} pyromellitamic acid (AP), 4,4′‐oxo bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl}phthalamic acid (AB) and 4,4′‐hexafluoroisopropylidene‐bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl}phthalamic acid (AF) were synthesized and characterized. These amines were prepared by solution condensation reaction of bis(3‐aminophenyl)methyl phosphine oxide (BAP) with 1,2,4,5‐benzenetetracarboxylic acid anhydride (P)/3,3′,4,4′‐benzophenonetetracarboxylic acid dianhydride (B)/4,4′‐(hexafluoroisopropylidene)diphthalic acid anhydride (F), respectively. The structural characterization of amines was done by elemental analysis, DSC, TGA, 1H‐NMR, 13C‐NMR and FTIR. Amine equivalent weight was determined by the acetylation method. Curing of DGEBA in the presence of phosphorylated amines was studied by DSC and curing exotherm was in the temperature range of 195–267°C, whereas with conventional amine 4,4′‐diamino diphenyl sulphone (D) a broad exotherm in temperature range of 180–310°C was observed. Curing of DGEBA with a mixture of phosphorylated amines and D, resulted in a decrease in characteristic curing temperatures. The effect of phosphorus content on the char residue and thermal stability of epoxy resin cured isothermally in the presence of these amines was evaluated in nitrogen atmosphere. Char residue increased significantly with an increase in the phosphorus content of epoxy network. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2235–2242, 2002

Effect of Phosphorus Content on Thermal Behaviour of Diglycidyl Ether of Bisphenol-A/phosphorus Containing Amines

Curing of diglycidyl ether of bisphenol-A (DGEBA) with phosphorus containing amide amines i.e. bis[3(3’-aminobenzamido phenyl)]methyl phosphine oxide (MB), bis[3(4’-aminobenzamido phenyl)]methyl phosphine oxide (PB), tris[3(3’-aminobenzamido phenyl)] phosphine oxide (MT) and tris[3(4’-aminobenzamido phenyl)] phosphine oxide (PT) and conventionally used curing agent 4,4’-diaminodiphenyl sulfone (D) was studied by DSC. The amines MB, PB, MT and PT were synthesised in the laboratory and were characterized by determining elemental composition, melting point, and amine equivalent. Structural characterization was done by 1 H-NMR and FTIR. The onset temperature of curing depended on the nucleophilicity of the amines and was in the order MT≈MB PB>PT>MT≈MB. The char residue of cured epoxy resin was significantly higher when phosphorus was incorporated in the cured network. Using mixed amine formulations based on amine D and P-containing amines and the molar ratio of these amines could easily control the curing characteristics. A linear relationship between char yield and P-content was observed in such formulations.

STUDIES ON THE PARTITIONING OF ACTINIDES FROM HIGH LEVEL WASTE USING A MIXTURE OF HDEHP AND CMPO AS EXTRACTANT

The paper describes the extraction and stripping behavior of actinides and lanthanides viz. americium, plutonium, uranium, cerium, and europium using a mixture of di-(2-ethylhexyl)phosphoric acid (HDEHP) and octyl(phenyl)-N,N-diisobutylcarbamoyl- methylphosphine oxide (CMPO) in n-paraffin as extractant. The extractant mixture combines the advantages of both the extractants for the partitioning of actinides from PUREX High Level Waste (HLW) solution. The extraction studies have been carried out from nitric acid medium as well as with simulated uranium-lean PUREX-HLW solution as relevant to Pressurized Heavy Water Reactor (PHWR) fuel reprocessing. The extracted actinides are stripped using a mixture of diethylenetriaminepentaacetic acid (DTPA), formic acid and hydrazine hydrate, leaving lanthanides in the organic phase. The lanthanides are subsequently stripped using a mixture of DTPA and sodium carbonate. The behavior of cesium, strontium, ruthenium, and zirconium is also studied using this mixed extractant.

Thermal characterization of diglycidyl ether of bisphenol‐A/phosphorus containing amines

AbstractIn order to improve the thermal resistance of diglycidyl ether of bisphenol‐A (DGEBA), phosphorus‐containing di‐ and tri‐amines, i.e., bis (3‐aminophenyl) methyl phosphine oxide (B) and tris (3‐aminophenyl) phosphine oxide (T), were used as curing agents. The effect of phosphorus content on the curing characteristics and char residue of cured resins in nitrogen atmosphere was evaluated by using different molar ratios of conventional curing agent, i.e. 4, 4′‐diaminodiphenyl sulfone (D) and amine B or T. Activation energy of curing, as evaluated by using the multiple heating rate method, was lowest when triamine T (61.0 kJmol−1) was used as hardener and was highest when D (68.7 kJmol−1) was used. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 390–395, 2001

Effect of structure on thermal behaviour of phosphorus containing addition polyimides and epoxy resins

Addition polyimides, [e.g. endo-5-norbornene-2.3-dicarboximide(nadimides), maleimides etc.] and epoxy resins have been used extensively in the past as matrix resins for advanced fiber-reinforced composites. However, inadequate flame resistance and thermal stability of these resins is one of their serious limitations. Our earlier studies have shown excellent flame resistance properties of addition polyimides based on bis(3-aminophenyl) methyl phosphine oxide (B) or tris(3-aminophenyl) phosphine oxide (T). Carbon fiber reinforced composites based on such matrix resin did not burn even in pure oxygen. In order to investigate the effect of weight percent of phosphorus on thermal behaviour and flame resistance, a series of addition polyimides and epoxy resins were prepared using B, T and amide-amines. The effect of structure on curing behaviour of resins and thermal and flame resistance of cured resins was evaluated. The results demonstrate an improvement in char yield of resins containing higher weight percent of phosphorus.

Extraction of palladium from nitric acid solutions by octyl(phenyl)-N,N-diisobutylcarbamoyl- methylphosphine oxide

Extraction behaviors of Pd(II) in the TRUEX and PUREX solvent extractions were studied by using octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide. The effect of scrubbing in the TRUEX solvent extraction was demonstrated by adding oxalic acid. The distribution ratios of palladium (D Pd's) in the diluted region of [HNO3] were found to depend strongly on the fraction of cationic species, Pd(NO3)+, existed in the aqueous phase. The gradual decrease of DPd with the increase of acidity beyond [H+] ≈ 1 mol·dm-3 was controlled by the formation of the anionic species Pd(NO3)3 -.

Structural and Thermal Characterisation of Nadimide Resins

A series of hexachloronadimides containing phosphine oxide in the backbone were synthesized by the reaction of bis(3-amino phenyl) methyl phosphine oxide (BAP) with pyromellitic dianhydride (PMDA)/3,3’,4,4’-benzophenone tetracarboxylic acid dianhydride (BTDA)/2,2-bis(3,4-dicarboxy phenyl) hexafluoropropane dianhydride (6F) and hexachloronadic anhydride in glacial acetic acid/acetone.

Microwave Catalyzed Reaction of H-Dimethylphosphonate with N-(2,3-Epoxypropyl)Phthmide

Microwave catalyzed reaction of N-(2,3-epoxypropyl)phthalimide with H-dimethylphosphonate for 4 min yielded via free radical processes: trimethylphosphonate, trimethylphosphate, N-(2-propenyl)phthalimide, 2-(N-phthalimidopropyl) dimethylphosphinates, hydrogen 3-(N-phthalimidopropyl) methylphosphine oxide, hydrogen 3-(N-phthalimidopropyl)methylphosphinate, 2-(N-phthalimidopropyl) dimethylphosphonate, and 2-(N-phthalimidopropyl) dimethyl-phosph-inate. The mechanism of formation of the various compounds along with their mass spectral fragmentation behavior is described in this communication.

Enhancement of the Mutual Separation of Lanthanide Elements in the Solvent Extraction Based on the CMPO-TBP Mixed Solvent by Using a DTPA-Nitrate Solution

The mutual separation behavior of rare earth elements was studied in the system based on the neutral extractant CMPO (n-octyl(phenyl)-N,N-diisobutylcarbamoyl methylphosphine oxide) and aminopolyacetic acid DTPA (diethylenetriamine pentaacetic acid). The extractability of lanthanides decreased monotonously with increasing of atomic number in the system of 0.2 M CMPO-1.0 M TBP-n-dodecane (TRUEX solvent) and 0.05 M DTPA-NaNCO3 or hydroxylamine nitrate (HAN) solution. The separation factor of La/Lu was 6,600 using 0.05 M DTPA-3M NaNO3 solution (initial pH=2.0). The mutual separation of lanthanides in the CMPO/DTPA system was greatly improved when compared with the general TRUEX system. The separation factor was not affected by the initial pH of the solution (1.8–2.2), the salting out reagent (NaNO3 and HAN), or its concentration (2, 3 M). The experimentally obtained separation factors of lanthanide elements were reproduced by a simple model based on the distribution ratios in the TRUEX extraction system and the stability constants of DTPA-metal complex. The mutual separation between light lanthanides is attributed to the selectivity of DTPA, while CMPO mainly influences the separation of heavy lanthanides.

The synthesis and properties of new epoxy resin containing phosphorus and nitrogen groups for flame retardancy

A new type of epoxy resin, which contained phosphorus oxide and nitrogen groups in the main chain, was synthesized. The structure of the new type of epoxy resin was confirmed by infrared (IR) spectroscopy, 1H nuclear magnetic resonance (1H-NMR), and 13C-NMR spectroscopic techniques. In addition, compositions of the new synthesized epoxy resin (TGDMO) with three curing agents, for example, bis(3-aminophenyl) methylphosphine oxide (BAMP), 4,4′-diaminodiphenylmethane (DDM), and 4,4′-diaminodiphenylsulfone (DDS), were used for making a comparison of its curing reactivity, heat, and flame retardancy with that of Epon 828 and DEN 438. The reactivities were measured by differential scanning calorimetry (DSC). Through the evaluation of thermal gravimetric analysis (TGA), those polymers which were obtained through the curing reactions between the new epoxy resin and three curing agents (BAMP, DDM, and DDS) also demonstrated excellent thermal properties as well as a high char yield. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 413–421, 1999

Enhancement of the Mutual Separation of Lanthanide Elements in the Solvent Extraction Based on the CMPO-TBP Mixed Solvent by Using a DTPA-Nitrate Solution.

The mutual separation behavior of rare earth elements was studied in the system based on the neutral extractant CMPO (n-octyl(phenyl)-N,N-diisobutylcarbamoyl methylphosphine oxide) and aminopolyacetic acid DTPA (diethylenetriamine pentaacetic acid). The extractability of lanthanides decreased monotonously with increasing of atomic number in the system of 0.2 M CMPO-1.0 M TBP-n-dodecane (TRUEX solvent) and 0.05 M DTPA-NaNCO3 or hydroxylamine nitrate (HAN) solution. The separation factor of La/Lu was 6,600 using 0.05 M DTPA-3M NaNO3 solution (initial pH=2.0). The mutual separation of lanthanides in the CMPO/DTPA system was greatly improved when compared with the general TRUEX system. The separation factor was not affected by the initial pH of the solution (1.8–2.2), the salting out reagent (NaNO3 and HAN), or its concentration (2, 3 M). The experimentally obtained separation factors of lanthanide elements were reproduced by a simple model based on the distribution ratios in the TRUEX extraction system and the stability constants of DTPA-metal complex. The mutual separation between light lanthanides is attributed to the selectivity of DTPA, while CMPO mainly influences the separation of heavy lanthanides.