The present research investigates the hydrolytic degradation of  poly(lactic acid) (PLA) plasticized with a natural wax and mixed with Zinc Oxide (ZnO) nanoparticles, functionalized and non-functionalized with Triethoxysilane. Different ZnO concentrations of 0, 0.1, and 1 wt% functionalized  and non-functionalized were added to an 85/15 PLA/Natural Wax (NWX) matrix using a Brabender internal mixing at 180 °C. For the study of hydrolytic degradation of the composites, type V probes (ASTM D638) were obtained by hot melt compression. Probes of each formulation were vertically positioned inside acrylic boxes. Hydrolytic degradation was carried out in tridistilled water at a temperature of 50 °C and initial pH 7.1, covering 1 cm above the sample. Degradation in probes was monitored for 2 months, extracting one specimen from the boxes at different intervals. Changes in weight, morphology and the rheological behavior of the blends were evaluated at different periods during degradation.

Monica Mendoza Duarte would like to acknowledge Centro de Investigacion en Materiales Avanzados (CIMAV), the Universidad Autonoma de Ciudad Juarez (UACJ), Universidad Tecnologica de Queretaro (UTEQ) for the facilities provided for this investigation. 

The authors would also like to thank Diana Abigail Lopez, Luis de la Torre Saenz and the Laboratorio Nacional de Nanotecnologi­a (Nanotech), especially to Karla Campos Venegas for technical support in SEM images.