Release of butylated hydroxytoluene (BHT) from Poly(lactic acid) films

The addition of butylated hydroxytoluene (BHT) to poly(lactic acid), PLA, films and its release into to three simulants (water, 95% ethanol and coconut oil) were evaluated. The decomposition temperature and tensile strength decreased in PLA-BHT films. The diffusion kinetics of BHT into ethanol 95% at 23, 31 and 43 degrees C gave diffusion coefficients between 10(-11) and 10(-9) cm(2) s(-1). The activation energy was calculated as 164.7 +/- 27.7 kJ mol(-1) for the diffusion of BHT from PLA-BHT films in ethanol. Release of BHT in water at 13, 23 and 43 degrees C and 100 days was not detected at the level of quantification of 1 mu g of BHT.mL(-1) of solution. PLA and PLABHT films stored in water at 43 degrees C for 100 days showed a reduction of 44% in the M-n. Films stored in fractionated coconut oil released 3.9 and 13.2% of BHT at 23 and 43 degrees C, respectively after 100 days. (C) 2011 Elsevier Ltd. All rights reserved.