IN-VITRO DETECTION OF 2,4-TDA AND 2,6-TDA AS DEGRADATION PRODUCTS OF A POLYESTERURETHANE FOAM

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-degrees-C. PU foams were first exhaustively extracted in methylene chloride at 37-degrees-C and subsequently subjected to mild hydrolysis in phosphate buffer pH 7.4 at 37-degrees-C. The amount of 2,4- and 2,6-TD at 37-degrees-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 +/-0.85mug/g of 2,4-TDA and 2.0 +/- 0.47mug/g of 2,6-TDA in the foam buffer extracts over 3.5 months of incubation at 37-degrees-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.