Phenylphosphine Oxide Research Articles

Synthesis and characterization of novel soluble poly(arylene ether amide triphenylphosphine oxide)s by heterogeneous palladium-catalyzed carbonylation polymerization

A new aromatic diiodide monomer, bis(4-(3-iodophenoxy)phenyl)phenylphosphine oxide (BIPPO), was prepared by condensation of bis(4-fluorophenyl)phenylphosphine oxide with 3-iodophenol. A series of poly(arylene ether amide triphenylphosphine oxide)s were synthesized via heterogeneous palladium-catalyzed carbonylative polycondensation of BIPPO, aromatic diamines, and carbon monoxide. Polymerization reaction proceeded smoothly in N,N-dimethylacetamide (DMAc) at 120 °C with 1,8-diazabicyclo[5,4,0]-7-undecene (DBU) as the base by using the bidentate phosphino-modified magnetic nanoparticles-anchored palladium complex [2P-Fe3O4@SiO2-PdCl2] as a recyclable catalyst under 1 bar of CO, producing new poly(arylene ether amide triphenylphosphine oxide)s with inherent viscosities ranging from 0.69 to 0.76 dl/g. All the polymers obtained were easily soluble in strong polar aprotic organic solvents and even in less polar pyridine at room temperature, and provided transparent, flexible and tough films by casting from their DMAc solutions. These polymers displayed good thermal stability with the glass transition temperatures ranging from 196 to 249 °C, the temperatures at 5% weight loss ranging from 441 to 490 °C in nitrogen. All the polymers were amorphous and their films showed good mechanical behavior with tensile strengths of 78.5–91.6 MPa, tensile moduli of 2.15–2.69 GPa, and elongations at break of 9.8–14.6%.

Highly flame retardant photocured paper coatings and printability behavior

Due to the high flammability of the paper, its use is restricted in advanced applications. In this study, UV‐cured paper coating formulations containing silica nanoparticles and phosphinoxide were prepared and coated on paper surface. Flammability, wettability, and printability properties were investigated. For this purpose, the surface of the silica nanoparticles was first functionalized with hydroxyethyl methacrylate (HEMA) ─OH. The hydroxylated silica nanoparticles were then modified with isocyanatoethyl methacrylate. Bis fluoro phenylphosphine oxide was synthesized by Grignard reaction elsewhere and OH modified in basic medium. Acrylate groups were added to BHPPO with isocyanatoethyl methacrylate to make it suitable for UV‐curing formulation. The chemical structures of the obtained substances were illuminated by ATR‐FTIR. UV‐cured paper coating formulations containing acrylated silica, acrylated phosphinoxide, and mixtures thereof were prepared and coated on the paper surface. Chemical structure, contact angle, surface energies, surface morphology, thermogravimetric analysis, and limited oxygen index of the coatings were determined. As a result, it has been concluded that coated papers have increased thermal stability in the nitrogen atmosphere. The highest thermal stability was observed in coatings containing nanosilica and it was determined that all of the coatings ignited later. Hybrid coatings made within the scope of this study have improved the printability properties as well as adding flame retardancy properties to the paper.

Designing superhydrophobic and flame retardant photo-cured hybrid coatings

The study investigates the effect of the addition of phenyl phosphine oxide (DAPPO) with acrylate functionality, polyhedral oligomeric silsesquioxane (POSS) (acr-POSS) with acrylate functionality and 1H,1H,2H,2H-Perfluorodecyl acrylate (PFOA) on the superhydrophobicity and fire-resistance of photo-curable urethane-acrylate coatings. The addition of DAPPO to urethane-acrylate (50 wt.%) improved flame resistance. The additions of acr-POSS and PFOA improved surface hydrophobicity through increasing surface roughness by the addition of acr-POSS and decreasing surface energy by the addition of PFOA. The flammability and surface properties of the photo-curable hybrid coatings were evaluated by measuring limiting oxygen index (LOI) and water contact angle (WCA), respectively. Compared with the only urethane-acrylate-containing coating, the final hybrid coating had an increased water contact angle from 72.7°±2 to 147.2°±2 and increased LOI from 17,0 ± 0.08–24,3 ± 0.08. In the final hybrid coating, extinguishing occurred in less than 10 s.

Design and synthesis of phenylphosphine oxide-based polymer photocatalysts for highly efficient visible-light-driven hydrogen evolution

We designed a series of phenylphosphine oxide derivatives as polymer photocatalysts for visible-light-driven hydrogen evolution. PCzBPO exhibited an excellent HER with a record high AQY of 14.88% at 460 nm.

Probing activated radioprotection of simple hydrophilic phosphonic acids in aqueous solution

Previous investigation into the radiation chemistry of the ligand octylphenyl-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) and its analogues demonstrated their ability to undergo activated radioprotection in an organic solvent – a feature most advantageous for spent nuclear fuel reprocessing scenarios. This phenomenon was dependent on these organophosphorus compounds forming a sacrificial complex involving extracted nitric acid and the presence of an adjacent phenylphosphine oxide motif in the molecule. However, the hydrophobic nature of these compounds prevented elucidation of which components were essential for activated radioprotection; for example, does the phenylphosphine oxide motif only require protonation, or simply the presence of complexed nitrate anion(s), or both? To begin to address these questions, we report on the effect of dissolved nitrate on the radiation chemistry of a series of simple hydrophilic phosphonic acids (methyl, ethyl, phenyl, and benzyl) in aqueous solution. An extensive suite of gamma irradiations supported by high performance liquid chromatography and nuclear magnetic resonance techniques was used to demonstrate that all four compounds were unable to undergo activated radioprotection. Although some nitrate protection was observed, this was attributed to changes in the available suite of radiolysis products, and not to the formation of nitrate-phosphonic acid sacrificial complexes. The absence of activated radioprotection and evidence for the formation of a [PhPA•NO3−] complex further supports the necessity of complex formation to activate the radioprotection mechanism.

Biocompatibility and cytotoxicity of novel photoinitiator π-conjugated dithienophosphole derivatives and their triggered polymers

Photoinitiators have widely been applied to industry, and now increasingly to clinical therapy. A novel high-performance photoinitiation system based on π-conjugated dithienophosphole derivatives (DTPs), including Ph-DTP and TPA-DTP, has recently been developed with high extinction coefficients and amazing polymerization initiating abilities at a relatively low dose in both the near-UV and visible light ranges, and TPA-DTP has better absorption characteristics than Ph-TPA. The purpose of this study was to evaluate cytotoxicity of DTPs and cytocompatibility of their initiated polymers by a MTT assay and calcein AM/propidium iodide staining. The cytotoxicity of Ph-DTP or TPA-DTP exposed to non-irradiation or irradiation is lower than bis (2,4,6-trimethylbenzoyl)-phenylphosphine oxide (BAPO) applied widely to industry. No obvious cytotoxicity was observed in the TPA-DTP-treated primary cells and various cell lines, while the activated Ph-DTP inhibited the cell viability and resulted in the massive cellular apoptosis and necrosis. Compared to camphorquinone (CQ) applied widely to clinical dental prosthetic restoration, the cytocompatibility of DTPs-photopolymerized BisGMA/TEGDMA polymers was inferior to CQ although their extracts exhibited low toxicity, indicating that TPA-DTP but not Ph-DTP is more suitable for industrial application. These results provide a novel insight into underlying potential application of DTPs to industrial deep polymerization or clinical tissue engineering rehabilitation.

High refractive and low birefringent materials based on Poly(arylene ether phosphine oxide)s and Poly(arylene ether phosphine sulfide)s

Poly(arylene ether phosphine oxide)s and poly(arylene ether phosphine sulfide)s with high refractive indices and low birefringences have been developed. The poly(arylene ether phosphine oxide)s were synthesized by the polycondensation of bis(4-fluorophenyl)phenylphosphine oxide with various bisphenols. Subsequently, the poly(arylene ether phosphine sulfide)s were synthesized by the sulfurization reaction of the poly(arylene ether phosphine oxide)s with Lawesson's reagent. These polymers have excellent thermal stabilities (Td5 > 490 °C), high glass transition temperatures (Tg = 198–281 °C), and no absorption in the visible light region. In addition, they achieve high refractive indices of 1.649–1.675 for the poly(arylene ether phosphine oxide)s and 1.671–1.691 for the poly(arylene ether phosphine sulfide)s owing to the highly polarizable P X (X = O, S) groups in their backbones. Their orientational birefringences (CR values) are in the range from +0.7 × 10−9 to +3.0 × 10−9 Pa−1, which are lower than those of the conventional poly(arylene ether ketone) and poly(arylene ether sulfone) (+7.8 × 10−9 and +4.0 × 10−9 Pa−1, respectively).

Michael addition in reactive extrusion: A facile sustainable route to developing phosphorus based flame retardant materials

This study addresses three very important aspects of sustainable development of new flame re-tardant material, i.e. in situ solvent free synthesis of flame retardant macromolecules during thermal processing of polymers, their leaching behavior from the polymer matrix and their preliminary toxicity assessment. Polyamide 6 (PA6) was functionalized by a novel reactive extrusion process. In situ synthesis of phosphine oxide based macromolecules was obtained via Michael addition reaction of divinyl phenyl phosphine oxide (DVPPO) and piperazine during the reactive extrusion process. The formation of phosphine oxide macromolecules (oligomers and low molecular weight polymers) were confirmed by NMR study of the modified PA6 polymer and UPLC-MS analysis of extracts from PA6 samples. Elemental analysis of the modified PA6 after the extraction with chloroform and water confirmed retention of majority of phosphorus species, confirming the beneficial effect of large macromolecular additives. This non-leaching behavior of modified PA6 is an important requirement for thin walled substrates like fibers and films where long-term durability is very important. The reactive extruded PA6 was successfully processed into textile fibers via melt spinning process in a laboratory spinning plant. The presence of phosphine oxide macromolecules in PA6 matrix had a lubricating effect, which has influence in the thermal processing and final properties of the fiber. The modified PA6 was evaluated for fire performance in small-scale fire tests where it showed improved fire performance. Moreover, the preliminary toxicity assessment of the relatively unknown DVPPO, via a well-established in vitro platform showed no adverse effects on cell viability.

Experimental and Molecular Simulation Studies of the Attachment Behavior of Photoinitiator XBPO Crystals in Different Solvents.

The aggregation of crystals is a common phenomenon during the crystallization process. However, the formation mechanism of the aggregates remains elusive. In this work, we combine experiments with molecular simulations to investigate the attachment behavior of an organic compound photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (XBPO) in different solvents. The simulation results were highly in line with the experimental results. The results indicate that the aggregation behavior occurs on the high-energy surface (1 0 0) and the attachment angle is 0° during the solvothermal process. Meanwhile, solvents play the critical role in the formation of aggregated particles. It was found that the solvents with high Kamlet-Taft dipolarity/polarizability can promote the aggregation behavior of photoinitiator XBPO crystals. Furthermore, a solvent-mediated growth mechanism assisted by "oriented attachment"-like and Ostwald ripening mechanisms was proposed to elucidate the growth and aggregation of particles. We anticipate that this study will provide a comprehensive understanding of the attachment behavior and be helpful to control the aggregation of crystals.

The Synthesis of New Type II Polymeric Photoinitiator (thioxantone) via Atom Transfer Radical Polymerization and Their Curing and Migration Studies

Polymeric photoinitiators are widely used in ultraviolet (UV)-curable printing inks because of their low migration behavior. In this study, a new phenylphosphine oxide-polystyrene-thioxanthone (PPO-PSt-TX) polymeric photoinitiator was synthesized. Bis[(4-hydroxy)phenyl]phenyl phosphine oxide (BHPPO) that was synthesized by Grignard technique, was functionalized with 2-bromopropionyl bromide (atom transfer radical polymerization (ATRP) initiator) and then used in styrene polymerization. The bromine end-capped polystyrene was then reacted with 2-thioxanthone-thioacetic acid and final polymeric photoinitiator PPO-PSt-TX was obtained. Proton nuclear magnetic resonance (1H NMR), attenuated total reflectance- Fourier transform infrared spectroscopy (ATR-FTIR), gel permeation chromatography (GPC) and ultraviolet-visible spectroscopy (UV-Vis) confirmed the obtained structure. The curing characteristic of PPO-PSt-TX was compared with a standard flexographic printing varnish formulation containing thioxanthone (TX). The photopolymerization kinetics were determined by photo differential scanning calorimetry (Photo-DSC). The conversion of methylmethacrylate polymerization by using macrophotoinitiator is 78%. The migration behavior of PPO-PSt-TX was identified with liquid chromatography-mass spectrometry (LC-MS). It was shown that PPOPSt- TX macro photoinitiator is suitable for flexographic varnish and the migration level of photoinitiator is reduced by using polymeric photoinitiator.

Synthesis and Characterization of Poly(aryl ether ether ketone ketone) Containing Phenyl Phosphine Oxide

Synthesis and Characterization of Poly(aryl ether ether ketone ketone) Containing Phenyl Phosphine Oxide

Synthesis and characterization of novel fluorinated poly(ether imide)s containing pyridine and/or phenylphosphine oxide moieties

4-(4-Trifluoromethylphenyl)-2,6-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]pyridine (9FPBAPP), as a new aromatic diamine, was prepared by a modified Chichibabin reaction of 4-(4-nitro-2-trifluoromethylphenoxy)acetophenone with 4-triflouromethylbenzaldehyde, followed by a catalytic reduction. A series of fluorinated poly(ether imide)s containing pyridine and/or phenylphosphine oxide moieties were prepared from bis(3-aminophenyl)phenylphosphine oxide (BAPPO), 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), and 9FPBAPP via a conventional two-step thermal imidization procedure with various mole ratios of BAPPO and 9FPBAPP. All the polymers were amorphous and soluble in common organic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone and had Tg’s of 277–285°C, 5% weight loss temperature of 521–550°C in nitrogen. Furthermore, high char yields and good limited oxygen index values indicated that these polymers exhibited good thermal stability and flame-retardant property. Tough and flexible polymer films also had good mechanical properties with tensile strengths of 75–99 MPa, tensile moduli of 1.1–1.6 GPa, and elongations at break of 12%–24% and low dielectric constants of 2.81–3.53 (1 MHz), as well as high optical transparency with the ultraviolet cutoff wavelength in the range of 350–384 nm.

All-Perovskite Emission Architecture for White Light-Emitting Diodes.

We demonstrate all-perovskite light-emitting diodes (PeLEDs) with white emission on the basis of simultaneously solving a couple of issues including the ion exchanges between different perovskites, solvent incompatibility in the solution process of stacking different perovskites and carrier transport layers, as well as the energy level matching between each layer in the whole device. The PeLEDs are built with a two-dimensional (CH3CH2CH2NH3)2CsPb2I7 perovskite that emits red light, CsPb(Br,Cl)3 quantum dots that emit a cyan color, and an interlayer composed of bis(1-phenyl-1H-benzo[ d]imidazole)phenylphosphine oxide (BIPO) and poly(4-butylphenyl-diphenyl-amine) (Poly-TPD). The interlayer is designed to realize desirable white electroluminescence by tuning the electron and hole transportation and distribution in-between multilayers. With this PeLED configuration, we achieve the typical white light with chromaticity coordinates of(0.32, 0.32) in Commission Internationale de L'Eclairage (CIE) 1931 color spacediagramand steady CIE coordinates in a wide range of driving current densities (from 2.94 to 59.29 mA/cm2). Consequently, our work, as the starting point for future research of all-perovskite white PeLEDs, will contribute to the future applications of PeLEDs in lighting and display. In addition, we believe that the proposed material and all-perovskite concept will leverage the design and development of more perovskite-based devices.

Synthesis and AO Resistant Properties of Novel Polyimide Fibers Containing Phenylphosphine Oxide Groups in Main Chain

A series of co-polyimide (PI) fibers containing phenylphosphine oxide (PPO) group were synthesized by incorporating the bis(4-aminophenoxy) phenyl phosphine oxide (DAPOPPO) monomer into the PI molecular chain followed by dry-jet wet spinning. The effects of DAPOPPO molar content on the atomic oxygen (AO) resistance of the fibers were investigated systematically. When the AO fluence increased from 0 atoms·cm−2 to 3.2 × 1020 atoms·cm−2, the mass loss of the fibers showed the dependence on DAPOPPO molar content in co-PI fibers. The PI fiber containing 40% DAPOPPO showed lower mass loss compared to those containing 0% and 20% DAPOPPO. At higher AO fluence, the higher DAPOPPO content gave rise to dense carpet-like surface of fibers. XPS results indicated that the passivated phosphate layer was deposited on the fiber surface when exposed to AO, which effectively prevented fiber from AO erosion. With the DAPOPPO content increasing from 0% to 40%, the retentions of tensile strength and initial modulus for the fibers exhibited obvious growth from 44% to 68%, and 59% to 70%, after AO exposure with the fluence of 3.2 × 1020 atoms·cm−2. The excellent AO resistance benefits the fibers for application in low Earth orbit as flexible construction components.

Examining the Influence of Organophosphorus Flame Retardants on the Thermal Behavior of Aromatic Polybenzoxazines

Abstract2,2‐bis(3,4‐Dihydro‐3‐phenyl‐2H‐1,3‐benzoxazine)propane (BA‐a) is blended with three commercial organophosphorus compounds, bis(4‐ hydroxyphenyl)phenylphosphine oxide (BHPPO), diphenyl phosphorami‐date (DPPA), and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), at different loadings (1–10 wt%). Incorporation of all dopants results in a reduction in the initiation temperature for the curing mechanism (by some 30–60 K), but only the DOPO truly moves the curing into a lower temperature regime by decreasing the end temperature by 25 K (DPPA lowered this by 5 K). DPPA and DOPO are also shown to have a significant effect on the enthalpy of polymerization each decreasing the value by 50 J g−1. Differential scanning calorimetry rescan indicates all three additives have a positive impact on the glass transition temperature of poly(BA‐a) with increases of 9 K (BHPPO) and 14 K (DPPA, DOPO). Thermogravimetric analysis indicates that all additives have little effect on the magnitude of char formed (BHPPO and DPPA both increased the char yield by 3%, whereas DOPO reduces the nal char yield by 3%). However, importantly, the mechanism of thermal degradation for poly(BA‐a) differs for all three additives and is shown to change with increasing concentra‐ tion. DOPO has the greatest effect on promoting the formation of char at elevated temperatures.

Relationship between C=C double bond conversion and dissolution kinetics in cross-linking-type photoresists for display manufacture, studied by real-time Fourier transform infrared spectroscopy and quartz crystal microbalance methods

Photoresists are an indispensable technology used for manufacturing electronic devices such as displays and semiconductors. In this study, we investigated the relationship between C=C double bond conversion and dissolution kinetics in cross-linking-type photoresists used for display manufacture using real-time Fourier transform infrared spectroscopy (FTIR) and quartz crystal microbalance (QCM) methods. To improve photoresist performance, it is important to understand the development mechanism of photoresists. Two kinds of polymers (a polymer with peeling-type dissolution and a polymer with a dissolution type with Case II diffusion) were used. 1,2-Octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime)] and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide were used as photoinitiators. The dissolution was of the peeling type when the polymers were formulated as a typical cross-linking-type photoresist. With increasing conversion ratio of C=C double bonds, the rate of developer intake decreased and the impregnation threshold before the onset of peeling increased and then decreased. It was also found that the dissolution kinetics were affected by the radicals generated upon the decomposition of photoinitiators.

Development of Siloxane Based Tetraglycidyl Epoxy Nanocomposites for High Performance Applications—Study of the Thermo Mechanical, Electrical, XRD, EDS and Physical Properties

A study was made in the present investigation on siloxane containing tetraglycidyl epoxy nanocomposites to find its suitability for use in high performance applications. The synthesis and characterization of the siloxane tetraglycidyl epoxy resin denoted as ‘E’ was done as reported in our previous study. Nanoclay and POSS-amine nano-reinforcements denoted as N1 and N2 were incorporated into the synthesized epoxy resin. Curing was done with diaminodiphenylmethane (DDM) and bis(3-aminophenyl) phenyl phosphine oxide (BAPPO) curing agents denoted as X and Y respectively. The mechanical, thermal, flame retardant and water absorption behavior of the epoxy nanocomposites were studied in our previous research paper. In our current research, we continue this study and analyze the thermo-mechanical, electrical, X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and physical properties (viscosity, epoxy equivalent weight (EEW) and gel permeation chromatography (GPC) studies).

Adhesion force measured by atomic force microscopy for direct carbon fiber-epoxy interfacial characterization

Adhesion force measurement by Atomic force microscopy (AFM) is used to investigate the interfacial interaction of the carbon fiber (CF)/epoxy composite for the first time. The epoxy functionalized AFM tip and three types of carbon fibers with different surface chemistry and morphologies were used in this study. Results show that the Bis (3-aminophenyl) phenyl phosphine oxide (BAPPO) modified CF possesses a much larger adhesion force (72.7 nN) than the as-received and de-sized CF (22.5 nN and 17.9 nN, respectively) due to formation of the chemical bonding between the BAPPO modified CF and the epoxy functionalized tip. Single fiber microbond test demonstrates that the interfacial shear strength (IFSS) of BAPPO modified CF/EP composite is 15% and 22% larger than that of as-received and de-sized CF/EP, respectively. This nanoscale manipulation by AFM provides a new avenue to measure the interfacial adhesion between the CF and epoxy at the molecular level.

The resolution of acyclic P-stereogenic phosphine oxides via the formation of diastereomeric complexes: A case study on ethyl-(2-methylphenyl)-phenylphosphine oxide.

As an example of acyclic P-chiral phosphine oxides, the resolution of ethyl-(2-methylphenyl)-phenylphosphine oxide was elaborated with TADDOL derivatives, or with calcium salts of the tartaric acid derivatives. Besides the study on the resolving agents, several purification methods were developed in order to prepare enantiopure ethyl-(2-methylphenyl)-phenylphosphine oxide. It was found that the title phosphine oxide is a racemic crystal-forming compound, and the recrystallization of the enantiomeric mixtures could be used for the preparation of pure enantiomers. According to our best method, the (R)-ethyl-(2-methylphenyl)-phenylphosphine oxide could be obtained with an enantiomeric excess of 99% and in a yield of 47%. Complete racemization of the enantiomerically enriched phosphine oxide could be accomplished via the formation of a chlorophosphonium salt. Characterization of the crystal structures of the enantiopure phosphine oxide was complemented with that of the diastereomeric intermediate. X-ray analysis revealed the main nonbonding interactions responsible for enantiomeric recognition.

Metal-Free One-Pot Synthesis of 3-Phosphinoylbenzofurans via Phospha-Michael Addition/Cyclization of H-Phosphine Oxides and in Situ Generated ortho-Quinone Methides.

A novel metal-free one-pot protocol for the effective and efficient synthesis of 3-phosphinoylbenzofurans via a phospha-Michael addition/cyclization of H-phosphine oxides and in situ generated ortho-quinone methides is described. Based on the expeditious construction of C(sp2)-P bonds, asymmetric synthesis of optically pure 3-phosphinoylbenzofurans containing chiral P-stereogenic center has also been probed by using chiral RP-(-)-menthyl phenylphosphine oxide.