Extraction of brominated flame retardents with supercritical CO2

In the field of polymer recycling and/or disposal of e.g. polymer composites of mass consumer products new techniques are highly required. For safety reasons polymer housings of mass consumer products e.g. computers, radios, TVs and other electrical household tools contain flame retardents, preferably brominated organic substances in amounts of 10 to 20 %. Commonly used disposal techniques of these halogen containing composites like incineration have the disadvantage that corrosive brominated gases and dioxines are formed and require costly and large-scale flue gas collectors. A direct recycling is not possible due to the fact that the components are difficult to seperate. One promising way to seperate halogenated name retardents out of polymer composites seems to be the extraction by supercritical fluids like CO2. Main objective of this paper is to find the suitable conditions for high extraction efficiencies. For model mixtures involving the flame retardents TBBA, TBPA and HBCD the extraction efficiency from the inert matrix MgSO4 was examined in relation to extraction pressure, temperature and time. The data form the basis for realistic tests on ABS composites with different flame retardents.