Analytical And Environmental Aspects of The Flame Retardant Tetra Bromo Bis Phenol A And Its Derivatives

Tetra Bromo Bis Phenol A or TBBPA is commonly used as a flame retardant and its derivatives. This flame retardant is covalently bound to Polycarbonate and Epoxy resins. The industrial production procedure entails brominating bisphenol-A with bromine while a solvent, like a halocarbon or methanol, is present.

The Analytical and Environmental Aspects of Tetra Bromo Bis Phenol A

Except in a few instances, TBBPA has not been considered a target compound itself but rather merely as a possible extra analyte. TBBPA is typically measured with phenolic organic compounds such as HBCD using LC-MS techniques.

1. TBBPA's physicochemical characteristics

Due to its distinct physicochemical characteristics, specific analytical techniques are needed to determine TBBPA. A sizable portion of the TBBPA is prevalent in its dissolved state in neutral environments. Maintaining a neutral environment while using polar solvent results in losses during the cleaning process.

It is important to take precautions to prevent these losses, and treating the raw extract with acidified water is one potential remedy. Only non-dissociated TBBPA is produced, and it is almost quantitatively pushed into the organic phase.

These characteristics significantly influence how TBBPA is distributed in the biota and the environment. TBBPA is primarily preserved in the blood via protein binding, as opposed to HBCDs and PBDEs, which are neutral compounds and do not accumulate in fatty tissues.

2. Extraction and cleanup

Different abiotic matrices can be used to review the extraction and cleanup of the flame retardant TBBPA.

Water

Large volumes of TBBPA are frequently required to ensure its positive detection due to the concentrations in water, which are expected to be low. In-situ acetylation is done before the solid-phase micro-extraction (SPME) step.

Considering the extraction temperature, extraction mode, fiber, and exposure of fiber over the headspace of the sample or directly into the sample, polydimethylsiloxane fiber is the best used for extracting TBBPA from water.

Sewage sludge, sediment, and soil

The primary method for identifying BFRs in sewage sludge, sediment, and soils is Soxhlet extraction, which is reliable, effective, and affordable. Generally, it has been found that the mixing of n-hexane and acetone in different proportions is one of the best recoveries for TBBPA.

Another method that may be used to evaluate TBBPA in sewage sludge, sediments, and dried soil is pressurized liquid extraction (PLE). Additionally, TBBPA can be simultaneously determined in sediment and sludge samples using liquid-liquid extraction (LLE) followed by SPE. 

Air

Particular occupational environments, like electronics dismantling plants, have higher indoor air concentrations of TBBPA. The particulate phase, instead of the vapor phase, is where TBBPA is primarily found.

As a result, TBBPA monitoring may not be appropriate for passive air sampling systems that primarily sample the vapor phase.

Indoor dust

Exposure risks to humans result from the presence of additive BFRs in indoor dust, including HBCDs and PBDEs. However, compared to PBDE and HBCD concentrations, TBBPA concentrations are at the lower end.

This is consistent with TBBPA being mainly used as a reactive FR and that, as a result, its release from treated goods is less straightforward than for compounds whose use pattern is exclusively or primarily as additive FRs.

Derivatives Of Tetra Bromo Bis Phenol A

The production process is primarily carried out in closed systems because of the byproducts that can be formed and the nature of the process. TBBPA is also employed in the production of derivatives. The derivatives can also be used as either additive or derivative intermediate in the manufacture of polymer.

The main TBBPA derivatives include;

1. TBBPA Bis (2-Hydroxy Ethyl Ether),

2. TBBPA Bis(Allyl Ether),

3. TBBP-A Dibromo Propyl Ether,

4. TBBPA Carbonate Oligomers, and

5. TBBPA Brominated Epoxy Oligomer.

TBBPA Bis (Allyl Ether) and TBBPA Bis (2-Hydroxyethyl Ether) are used as flame retardants in resins and plastics.

Furthermore, TBBPA bis (2-Hydroxyethyl Ether) is used in engineering polymers, coatings, adhesives, polyurethane, thermoplastics polyesters, and epoxy resins as additive FR. TBBPA Bis(Allyl Ether) is also employed in polystyrene foams as a reactive FR.

Flame retardant polypropylene is used in textiles, and electronic and electrical applications, including TV yokes, housings of electrical appliances, cable wire, connectors, coil bobbins, lamp sockets, or wire nuts. It is primarily used in pipes for water discharge in building applications and in sheets or film for roofing.

Another name for TBBPA glycidyl ethers is TBBP-A brominated epoxy oligomers. Brominated epoxy oligomers come in two distinctly different chemical forms. Similar to epoxy resins used for making printed circuit boards, one has two epoxy groups at the end of the molecule (EP-type).

The other form, TBBPA epoxy end-capped with tribromophenol (EC-type), is devoid of reactive groups. Both oligomers are reactive FRs employed in housings for industrial machinery and electrical or electronic components made of thermosetting resins, polybutylene terephthalate, polybutylene terephthalate-alloys, ABS, ABS/polycarbonate, and HIPS.

Depending on the application, the molecular weight of its products differs. When TBBPA reacts with phosgene, TBBPA carbonate oligomers are created. They can be compared to how TBBPA is used reactively in polycarbonates.

These oligomers are employed as additive FRs in engineering thermoplastics like phenol-formaldehyde resins, Poly(Ethylene Terephthalate), ABS, Polycarbonate, and Poly(Butylene Terephthalate).

Conclusion

The flame retardant TBBPA is a reactive BFR. Since addictive BFRs like PBDEs and HBCDs are more prevalent, their release from treated goods is less noticeable. TBBPA is used to make derivatives. The derivatives can also produce polymers as additives or derivative intermediates. The physical and chemical properties, as well as extraction and cleanup, form part of the analytical and environmental aspects of TBBPA.