scholarly journals Mechanistic Aspects of Condensed- and Gaseous-Phase Activities of Some Phosphorus-Containing Fire Retardants

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1801 ◽  
Author(s):  
Ananya Thomas ◽  
Malavika Arun ◽  
Khalid Moinuddin ◽  
Paul Joseph
Keyword(s):  
Gaseous Phase ◽  
Polymeric Materials ◽  
Vapour Phase ◽  
Phosphine Oxides ◽  
Organic Substances ◽  
Complementary Information ◽  
Ammonia Gas ◽  
Calorimetric Measurements ◽  
Phosphorus Containing ◽  
Solid Additive

As a part of our ongoing investigations on passively fire protecting polymeric materials, we have been employing both reactive and additive routes involving phosphorus-containing compounds. These included inorganic and organic substances, and in the latter case, the phosphorus-bearing groups differed in terms of the chemical environments (phosphite, phosphate, phosphine, phosphine oxide and phosphonate ester) and oxidation state of the P atom (i.e., III, or V). The overall flammability profiles of wood substrates coated with the phosphorus-containing compounds were obtained through cone calorimetric measurements. The elemental composition, morphology and chemical natures of the char residues, obtained from the cone tests, were analysed through a variety of spectroscopic, chromatographic and spectrometric means. From the complementary information, obtained through these analyses, some probable mechanistic pathways that underpin the condensed- and gaseous-phase activities of the different additives are suggested. It was found that the inorganic solid additive, i.e., (NH4)2HPO4, underwent a two-step degradation, yielding ammonia gas and phosphoric acid. Furthermore, the liquid additives, owing to their volatility as compared to the solid ones, showed a relatively higher presence in the vapour phase than volatile fragments emanating from the latter ones (i.e., from phosphine and the phosphine oxides).

scholarly journals Synthesis of Phosphorus-Containing Polyanilines by Electrochemical Copolymerization

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1029 ◽  
Author(s):  
Beatriz Martínez-Sánchez ◽  
Andrés Felipe Quintero-Jaime ◽  
Francisco Huerta ◽  
Diego Cazorla-Amorós ◽  
Emilia Morallón
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polymeric Materials ◽  
Electroactive Polymers ◽  
Hydrogen Electrode ◽  
X Ray ◽  
Electrochemical Copolymerization ◽  
Phosphorus Containing ◽  
Redox Transitions ◽  
Acid Stable

In this study, the phosphonation of a polyaniline (PANI) backbone was achieved in an acid medium by electrochemical methods using aminophenylphosphonic (APPA) monomers. This was done through the electrochemical copolymerization of aniline with either 2- or 4-aminophenylphosphonic acid. Stable, electroactive polymers were obtained after the oxidation of the monomers up to 1.35 V (reversible hydrogen electrode, RHE). X-ray photoelectron spectroscopy (XPS) results revealed that the position of the phosphonic group in the aromatic ring of the monomer affected the amount of phosphorus incorporated into the copolymer. In addition, the redox transitions of the copolymers were examined by in situ Fourier-transform infrared (FTIR) spectroscopy, and it was concluded that their electroactive structures were analogous to those of PANI. From the APPA monomers it was possible to synthesize, in a controlled manner, polymeric materials with significant amounts of phosphorus in their structure through copolymerization with PANI.

scholarly journals Mode of Action of Condensed- and Gaseous-Phase Fire Retardation in Some Phosphorus-Modified Polymethyl Methacrylate- and Polystyrene-Based Bulk Polymers

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3402
Author(s):  
Paul Joseph ◽  
Malavika Arun ◽  
Stephen Bigger ◽  
Maurice Guerrieri ◽  
Doris Pospiech ◽  
...  
Keyword(s):  
Polymethyl Methacrylate ◽  
Gaseous Phase ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Bulk Polymerization ◽  
Inductively Coupled ◽  
Gaseous Products ◽  
Phosphorus Containing ◽  
Ft Ir ◽  
Bulk Polymers

The aspects of fire retardation in some phosphorus-modified polymethyl methacrylate (PMMA) and polystyrene (PSt) polymers are reported in the present paper. Both additive and reactive strategies were employed to obtain the desired level of loading of the phosphorus-bearing compound/moiety (2 wt.% of P in each case). Test samples were obtained using bulk polymerization. The modifying compounds contained the P-atom in various chemical environments, as well as in an oxidation state of either III or V. With a view to gain an understanding of the chemical constitution of the gaseous products formed from the thermal decomposition of liquid additives/reactives, these materials were subjected to GC/MS analysis, whereas the decomposition of solid additives was detailed using the pyrolysis-GC/MS technique. Other investigations included the use of: Inductively-coupled Plasma/Optical Emission Spectroscopy (ICP/OES), solid-state NMR and FT-IR spectroscopy. In the case of PMMA-based systems, it was found that the modifying phosphonate ester function, upon thermal cracking, produced ‘phosphorus’ acid species which initiated the charring process. In the case of solid additives, it is more likely that the resultant phosphorus- and/or oxygenated phosphorus-containing volatiles acted as flame inhibitors in the gaseous phase. With the PSt-based systems, a probable process involving the phosphorylation of the phenyl groups leading to crosslinking and char formation is feasible.

scholarly journals FLAME RETARDATION PERFORMANCES OF HALOGEN-FREE FLAME RETARDANT WHEN APPLIED TO UNSATURATED POLYESTER

2012 ◽  
Vol 15 (3) ◽  
pp. 73-79
Author(s):  
Quy Thi Dong Hoang ◽  
Cuong Ngoc Hoang ◽  
Anh Huynh Tram Pham ◽  
Vien Tri Thiem ◽  
Huong Ngoc Nhu Nguyen ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Condensed Phase ◽  
Mode Of Action ◽  
Flame Retardants ◽  
Unsaturated Polyester ◽  
Polymeric Materials ◽  
Vapour Phase ◽  
Dominant Mode ◽  
Ul 94 ◽  
Flame Retardant Properties

In order to improve fire performance of polymeric materials, phosphorus flame retardants (FRs) were studied in an attempt to obtain UL-94 ratings for materials based on unsaturated polyester. The fire behaviors and thermal stability properties were evaluated using UL-94 vertical test and thermogravimetric analysis (TGA). The UL-94 test results show that V-1 rating is achieved. TGA and UL-94 results concluded that phosphorus FRs employed in this study works on both vapor phase and condensed phase, but the vapour phase is dominant mode of action. These suggested that the addition of FRs probably does affect on the char layer formed during combustion behavior and increase the flame retardant properties in the case of condensed phase mode of action. The efficiency of flame retardant of phosphorus also highly depends upon the phosphorus moieties generated during the decomposition which further converted to radical capturing species, and consequently quenching the flame in the case of gas phase mode of action. These FRs can be promising candidates that replace the halogen-based.

Synthesis of 2H-azirinyl phosphonates and phosphine oxides from phosphorus containing allenes

2016 ◽  
Vol 191 (11-12) ◽  
pp. 1464-1466 ◽  
Author(s):  
Valery K. Brel ◽  
Ekaterina Yu. Kovaleva ◽  
Yulia V. Nelyubina
Keyword(s):  
Phosphine Oxides ◽  
Phosphorus Containing

scholarly journals Asymmetric Synthesis of the Two Enantiomers of β-Phosphorus-containing α-Amino Acids via Hydrophosphinylation and Hydrophosphonylation of Chiral Ni(II)-Complexes

2021 ◽  
Author(s):  
Isabelle Gillaizeau ◽  
Yoshinori Tokairin ◽  
Hiroyuki Konno ◽  
Angéline Noireau ◽  
Caroline West ◽  
...  
Keyword(s):  
Amino Acids ◽  
Asymmetric Synthesis ◽  
Michael Addition ◽  
Secondary Phosphine ◽  
Phosphine Oxides ◽  
New Approach ◽  
Phosphorus Containing ◽  
Dialkyl Phosphites

A new approach for the asymmetric synthesis of the two enantiomers of β-phosphorus-containing α-amino acids was developed via Michael addition of secondary phosphine oxides and dialkyl phosphites to chiral Ni...

scholarly journals Potential Synergism between Novel Metal Complexes and Polymeric Brominated Flame Retardants in Polyamide 6.6

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1543 ◽  
Author(s):  
Alistair F. Holdsworth ◽  
A. Richard Horrocks ◽  
Baljinder K. Kandola
Keyword(s):  
Flame Retardants ◽  
Vapour Phase ◽  
Environmental Concerns ◽  
Antimony Trioxide ◽  
Release Rates ◽  
Cone Calorimetry ◽  
Phosphorus Containing ◽  
Brominated Polystyrene ◽  
Polyamide 6.6 ◽  
Phase Activity

While environmental concerns have caused polymeric brominated primary flame retardants (PolyBrFRs) to be effective replacement monomeric species, few alternatives for antimony trioxide (ATO) have been developed beyond the zinc stannates (ZnSs). Previous research, which explored the interactions of aluminium (AlW), tin (II) (SnW) and zinc (ZnW) tungstates with several phosphorus-containing flame retardants in polyamide 6.6 (PA66), is extended to two PolyBrFRs: brominated polystyrene (BrPS), and poly(pentabromobenzyl acrylate) (BrPBz). On assessing the effect of each tungstate on the thermal degradation and flammability in combination with each PolyBrFR using TGA, UL94, LOI, cone calorimetry and TGA-FTIR, only ZnW and SnW showed significant increases in LOI (>26 vol.%). Both ZnW-BrPS- and ZnW-BrPBz-containing formulations yielded average UL94 ratings ≥ V-2 and TGA char residues (corrected for metals content at 500 °C) in air > 15 wt.%. BrPS-containing samples, especially those containing ZnW and SnW, generated peak heat release rates approximately 50% lower than the equivalent BrPBz samples. These reductions did not correlate with respective increases in LOI, suggesting that tungstate-PolyBrFR combinations influence pre-ignition differently to post-ignition behaviour. Calculated synergistic effectivities indicate that ZnW functions as a synergist in both pre- and post-ignition stages, especially with BrPS. TGA-FTIR and char analyses showed that, in addition to the vapour-phase activity normally associated with PolyBrFRs, condensed-phase processes occurred, especially for the ZnW-PolyBrFR combinations. Additionally, ZnW demonstrated significant smoke-suppressing properties comparable with zinc stannate (ZnS).

Transport Coefficients of Ammonia Gas in Thermoplastic Polymers and Nanocomposites Used for Microelectronic Substrates Containers

2020 ◽  
Vol 27 ◽  
pp. 63-72
Author(s):  
Minh Phuong Tran ◽  
Paola González-Aguirre ◽  
Carlos Beitia ◽  
Jorgen Lundgren ◽  
Sung In Moon ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Raw Materials ◽  
Transport Coefficients ◽  
Polymeric Materials ◽  
Desorption Kinetics ◽  
Cross Contamination ◽  
Barrier Material ◽  
Ammonia Gas ◽  
Molecular Contaminants ◽  
Metallic Corrosion

Polymeric plastic boxes (named Front Opening Unified Pods (FOUP)) were widely used in semiconductor manufacture to maintain the cleanliness of processed wafer substrates in a controlled mini-environment. Polymeric materials, however, are able to sorb airborne molecular contaminants (AMCs) and subsequently to outgas the sorbed AMCs backward to FOUP’s atmosphere, causing the transfer of AMCs to sensitive stored substrates, named cross-contamination. As a type of AMCs, the NH3 cross-contamination could cause a severe yield loss to integrated circuits (crystals (haze), resist-development defects (T-topping) or metallic corrosion). Experiments were carried out to establish the NH3 sorption and desorption kinetics in polyetherimide (PEI), Entegris Barrier Material (EBM)), and EBM/carbon nanotubes (EBMCNT) at NH3 concentration of 800-ppbv, 21°C, and relative humidity of 40%. The transport coefficients i.e. solubility and diffusivity (DNH3 and SNH3) were then determined. The study on NH3 provides an additional guideline to choose the best raw materials for FOUP formulation in taking into account the potential cross-contamination of AMCs. Numerical simulation model based on obtained solubility and diffusivity values was conducted to demonstrate NH3 concentration profiles in FOUP walls during contamination and FOUP decontamination, which are inaccessible by conventional experiments.

ChemInform Abstract: PHOSPHORUS-CONTAINING INTERMEDIATES AND DYES. II. AZO DYES CONTAINING TERTIARY PHOSPHINE OXIDES AND DIETHYLPHOSPHINATES

1976 ◽  
Vol 7 (14) ◽  
pp. no-no
Author(s):  
V. V. KORMACHEV ◽  
S. N. CHALYKH ◽  
E. A. CHALYKH ◽  
A. A. SAZANOVA ◽  
V. A. KUKHTIN
Keyword(s):  
Azo Dyes ◽  
Phosphine Oxides ◽  
Tertiary Phosphine ◽  
Phosphorus Containing
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