Development of plastic disks containing flame retardants for elucidating changes in their concentrations due to simulated weathering and the application of these disks to weathering tests

Abstract

Flame retardants (FRs) are useful because they can prevent combustion and delay the spread of fire after the ignition on commercial products containing plastics. However, such commercial products could be a primary source of environmental contamination with FRs. Plastic disks containing FRs were prepared to elucidate changes in the concentrations of the FRs after weathering tests. Acrylonitrile-butadiene-styrene (ABS) and polycarbonate (PC) resin were separately kneaded with a combination of three organic FRs [Dechlorane plus (DP), tetrabromobisphenol A (TBBPA), and triphenyl phosphate (TPhP)] and one inorganic FR [antimony trioxide (SbO)]. The concentrations of TBBPA/TPhP and DP/SbO in the final preparations were respectively 1000 and 500 mg/kg in compliance with the RoHS directive on organobromine FR. The concentrations of elements in the final preparations were 300 mg/kg for chlorine, 600 mg/kg for bromine, 100 mg/kg for phosphorus, and 400 mg/kg for antimony, respectively. The analytical concentrations (three FRs and four elements) were consistent with the expected concentrations (maximum difference -9.5% in the PC disks). The FRs and elements in the disks were sufficiently homogenous (maximum inhomogeneity 4.3% in the PC disks). The prepared disks were subjected to weathering tests; the concentrations of TBBPA in the disks decreased significantly (30 to 40%) whereas the concentrations of the elements did not change under the condition of this study. On the other hand, there were no drastic differences on relationships of FRs and elements such as DP/chlorine and TPhP/phosphorus.

Effect of Long-time Heating for Elements from Flame Retardants in Acrylonitrile Butadiene Styrene and Polycarbonate Resin Disks

“…The concentrations of DP, TBBPA, TPhP, Cl, Br, P, and Sb in ABS and PC resin disks are listed in Table 1 and details of the preparation procedure are described in our previous study. 13,14,19 The original ABS and PC resin disks (without long-time heating) used in the present study can be seen in Photos 1 and 2, respectively. The diameter and the thickness of the original disk were 30 and 2 mm, respectively; and the original masses of ABS and PC resin disks were ca.…”

“…11,12 From this point of view, we prepared plastic disks for both ABS and PC resins containing FRs and homogeneities of FRs were evaluated in our previous study. 13,14 The FRs contained in these plastic disks were dechlorane plus (DP), tetrabromobisphenol A (TBBPA) and triphenyl phosphate (TPhP) which were selected as organochlorine, organobromine and organophosphorus FRs, respectively. The Sb2O3 was also added to the ABS and PC resin disks as an inorganic FR.…”

“…In addition, the plastic disks could be used to evaluate the behavioral differences among FRs in polymers under environmental changes since three or four FRs were contained in the same disks and their concentrations were properly determined. 13,14 Consequently, the simulated weathering tests, which were independently set as outdoor or indoor exposure in compliance with the ISO 4892-2:2006, 16 were also performed with respect to the plastic disks. 13,14 As results, FRs in the plastic disks showed small changes in their concentrations due to the partly decomposition of their chemical forms under the simulated weathering tests which were assumed as scrapyard or office environments for ca.…”

“…6 months. 13,14,[17][18][19] On the other hand, another question came out if the plastic disks were exposed to a harder environment such as a higher temperature. It is well known that X-ray fluorescence (XRF) spectrometry is expected to be useful for direct and speedy analysis of hazardous substances in electrical and electronic equipment [20][21][22][23] and also described in the IEC 62321 as a screening method with respect to RoHS directive.…”