Development of efficient techniques for the removal of brominated flame retardants from polymer blends with composition that simulates WEEE

Waste electric and electronic equipment (WEEE) has increased enormously because of the rapid expansion and consumption of electronic devices and their short lifespan. Recycling of WEEE is challenging, due to the presence of various materials including glass, metals and plastics (Buekens and Yang 2014). Brominated flame retardants (BFR), such as tetrabromobisphenol A (TBBPA) that are often added into plastics are toxic substances that must be removed before or during recycling (Ma et al. 2016). Pyrolysis is an environmentally friendly method, since secondary valuable materials or monomers can be recovered (Antonakou et al. 2014). In this work solvent extraction prior to pyrolysis is examined as a pretreatment method, in order to reduce the bromine content in specific brominated-polymeric blends. The blends consist of acrylonitrile-butadiene-styrene (ABS), high-impact polystyrene (HIPS), polycarbonate (PC) and polypropylene (PP), along with TBBPA, which is the tested BFR. Different solvents as well as different extraction times were investigated. Before and after pretreatment, blends were analysed by X-ray fluorescence (XRF) so as to estimate the bromine content; and were also pyrolysed in order to evaluate the derived products and examine if brominated compounds continue to form. XRF and pyrolysis experiments indicate that reduction of bromine can be effectively achieved.