In-vitro detection of 2,4- and 2,6-TDA as degradation products of a polyesterurethane foam

Abstract

The polyesterurethane (PU) foam, also known as Scotfoam or Microthane foam, was found to produce 2,4- and 2,6-toluene diamine (TDA) in the aqueous extracts following approximately 3·5 months of incubation in phosphate buffer pH 7·4 at 37°C. PU foams were first exhaustively extracted in methylene chloride at 37°C and subsequently subjected to mild hydrolysis in phosphate buffer pH 7·4 at 37°C. The amount of 2,4- and 2,6-TDA at 37°C at different time intervals were determined using high pressure liquid chromatography (HPLC) with UV photodiode array detector and gas chromatography/mass spectroscopy (GC/MS). Following exhaustive washing of the foam, measurement of 2,4- and 2,6-TDA showed total cumulative levels of 2·81 ± 0·85 μg/g of 2,4-TDA and 2·0 ± 0·47 μg/g of 2,6-TDA in the foam buffer extracts over 3·5 months of incubation at 37°C. The linear kinetics obtained for TDA formation with time ( R(2,4) = 0·964 and R(2,6) = 0.982) indicates hydrolysis of the PU foam, not contamination from manufacturing process or analytical procedure used.