The article contains sections titled: 1. Organic Bromine Compounds 1.1. Physical Properties 1.2. Chemical Properties 1.2.1. Nucleophilic Displacement of Bromine 1.2.2. Displacement of Bromine by Metals 1.3. Production 1.3.1. Addition Reactions 1.3.2. Substitution Reactions 1.4. Commercial Products 1.4.1. 1,2‐Dibromoethane 1.4.2. 1‐Bromo‐3‐chloropropane 1.4.3. 1‐Bromo‐2‐phenylethane 1.4.4. 1‐(Bromomethyl)‐3‐phenoxybenzene 1.4.5. Bromoacetic Acid 1.4.6. Bromomethane 1.4.7. 3‐Bromo‐1‐propene 1.4.8. Bromochloromethane and Dibromomethane 1.4.9. Trifluorobromomethane and Difluorobromochloromethane 1.4.10. Flame Retardants 1.4.11. Biocides 1.4.12. Pharmaceuticals 1.4.13. Dyes and Indicators 1.5. Manufacturers 1.6. Toxicology and Occupational Health 2. Inorganic Bromine Compounds 2.1. Hydrogen Bromide and Bromides 2.1.1. Hydrogen Bromide 2.1.2. Bromides 2.2. Hypobromous Acid, Hypobromites 2.3. Bromous Acid, Bromites 2.4. Bromic Acid, Bromates
Two new 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO)-containing compounds, (6,6′-(1-methylethylidene)-bis(9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide)) (bis-DOPO) and 2,4,6-tris-(9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide)-1,3-diacetoxybenzene (DOPO-RA), were synthesized and characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. These new flame retardants were incorporated into epoxy formulations to produce a copper-clad laminate. When fully cured, the DOPO-groups of bis-DOPO become a part of the epoxy chains, whereas the DOPO-groups of DOPO-RA remain pendant to the epoxy polymer network. Despite their higher phosphorus content, bis-DOPO-based laminates showed a poorer flame-retardant performance compared to the DOPO-RA laminates. It is believed that the pendant position of the DOPO group with respect to the polymer chains is essential for a gas-phase flame-retardant action.
In the view of many national and international human health and environmental regulations, polymeric flame retardants are sustainable products. In this work, a series of high molecular weight and polymeric brominated flame retardants are synthesized by the alkylation of aromatic molecules or the alkylation of aromatic polymers with pentabromobenzyl bromide (PBBB) or tetrabromoxylylene dibromide (TBXDB). The flame retardants prepared via the alkylation of toluene or diphenylethane with PBBB were found to be not truly polymeric but had high Mw > 1400. However, the alkylation of the same aromatic molecules by a mixture of PBBB and TBXDP resulted in polymeric flame retardants with Mw > 130,000. Two other polymeric flame retardants were prepared by the alkylation of aromatic polymers (polyphenylene ether or polystyrene) with PBBB. It was found that the new flame retardants had a high bromine content of more than 68%. They showed high thermal stability with the onset of thermal decomposition above 360 °C and a maximum rate of weight loss at about 375–410 °C. The newly synthesized flame retardants were tested in different thermoplastics. Flame retardant efficiency and physical properties were comparable or better than the reference commercial flame retardants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.