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Phosphorous-Based FRs
Published in Asim Kumar Roy Choudhury, Flame Retardants for Textile Materials, 2020
P-C bond creation and its use in synthetic chemistry offer a wide range of possible design and development of exciting organophosphorus flame retardants. Conventional synthetic methodologies, namely Michael addition, Michaelis–Arbuzov, Friedels–Crafts, and Grignard reactions are the most commonly used by academics for development of P-C bonded flame retardants. Use of, for example, green reagents, catalytic reactions, microwave technology, and photo-initiated reactions. are increasingly used by researchers to synthesize P-C containing organophosphorus compounds. Recently, aromatic DOPO-based phosphinate flame retardants have been developed with relatively higher thermal stabilities (>250°C). Such compounds have potential as flame retardants for high-temperature-processable polymers, such as polyesters and polyamides. A vast variety of P-C bond containing efficient flame retardants are being developed; however, further work in terms of their economical synthetic methods, detailed impact on mechanical properties and processability, long term durability, and their toxicity and environmental impact is much needed for their potential commercial exploitations. (Wendels et al., 2017).
A Review on the Application of Quaternary Ammonium-Based Ionic Liquids in Mineral Flotation
Published in Mineral Processing and Extractive Metallurgy Review, 2020
Hrushikesh Sahoo, Swagat S. Rath, Bisweswar Das
Apart from the publications discussed above, there are some recent studies of ILs, which report new applications of ILs. Zheng et al. (2019) tested 16 ILs to determine the dissolution and suspension behavior of Asphaltene precipitate. Trihexyl (tetradecyl)phosphonium bis(2,4,4-trimethylphenyl)phosphinate and trihexyl(tetradecyl)phosphonium bis(2-ethylhexyl)phosphate were found to be the best among all the ILs used. IL has also been used as an environment-friendly solvent. Sulaiman et al. (2019) investigated the use of IL as a replacement of volatile solvents that treat harmful chlorophenols generated in textile, pharmaceutical, metallurgical, pulp, and paper manufacturing. It was observed that, in spite of the number of chlorine atoms and temperature, the degree of solubility depends on the structure of both ILs and chlorinated phenols. In another important work, depolymerization of polyamide 6 in hydrophilic ILs under microwave radiation for 60 min resulted in the easy recovery of caprolactam through the extraction process. The study facilitated to avoid the energy consuming direct distillation procedure (Kamimura et al. 2019).
Binding of Divalent Transition Metal Ions to Immobilized Phosphinic Acid Ligands. Part I. Characterization by Fourier Transform Infrared Spectroscopy
Published in Solvent Extraction and Ion Exchange, 2021
Spiro D. Alexandratos, Xiaoping Zhu, Mateusz R. Marianski
There are similarities between the spectra from this work and those with trivalent ions.[35] In the latter, the P = O (1168 cm−1, 1126 cm−1) and P-O (967 cm−1, 951 cm−1) bands in the phosphinic acid show the same behavior as here in that the bands at 1168 cm−1 and 951 cm−1 decrease in intensity, 1126 cm−1 shifts to 1129 ±6 cm−1 while 951 cm−1 blue-shifts by up to 30 cm−1. A new band forms at 1072 cm−1, 1044 cm−1, 1057 cm−1, 1043 cm−1 and 1049 cm−1 for Al(III), La(III), Lu(III), Fe(III), In(III) which was ascribed to a delocalized POO(M). The broadness of the band precluded identifying a new second band. This points to similar binding mechanisms. The new POO(M) band for trivalent ions is ≈ 25 cm−1 higher than that with divalent ions which indicates a stronger bond within the POO moiety and a weaker bond to the trivalent ion. This is consistent with the understanding that the trivalent ion bound to the phosphinate is not the “bare” M3+ ion but, rather, the ion bound to a nitrate to give M(NO3)2+. This was noted earlier[35] by showing the slope of a plot of log D vs. pH was 2.0. Additional support is that the FTIR spectra of the phosphinate with bound trivalent ions have a broad band at 1280 cm−1 – 1330 cm−1 which is consistent with the asymmetric NOO moiety; that band is absent in the spectrum of the phosphinic acid appearing in the paper as well as phosphinate loaded with M2+ in the current paper (Figure 2).[39]
Investigations on the use of commercial phosphonic acid derivative for the extraction and separation of Zr(IV) and Nb(V) from their admixture in nitric acid solution
Published in Journal of Dispersion Science and Technology, 2023
Botros Abdelnaser Masry, Mohammad Mohammad Zeid, Amany tighian Kassem, Hala G. Nowier, Jacqueline A. Daoud
For the extraction and separation of Zr and Nb, several phosphonic and alkyl phosphoric acid derivatives were employed. These technologies included solvent extraction using cyanex 925,[16–18] tri-n-butyl phosphinate,[19] cyanex-272 and TBP,[20] and tri-n-butyl phosphate,[21] as well as ion exchange.[22–25] The liquid–liquid extraction technique normally requires very little equipment and is quick, simple, and less expensive.