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 °C gave diffusion coefficients between 10−11 and 10−9 cm2 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 °C and 100 days was not detected at the level of quantification of 1 μg of BHT.mL−1 of solution. PLA and PLABHT films stored in water at 43 °C for 100 days showed a reduction of 44% in the Mn. Films stored in fractionated coconut oil released 3.9 and 13.2% of BHT at 23 and 43 °C, respectively after 100 days.