Vegetable oils (VOs) can be used as plasticizers or as biodegrading additives for commercial polymers. According to the literature, the use of concentrations higher than 5% of oils added to polymers or their mixtures indicated loss of mechanical properties on the final product. However, VOs can be used as a compatibilizer for the mixture of synthetic polymers with biopolymers (PM) under concentrations higher than 5%. Moringa oleifera oil (MO) was used as a compatibilizer to PM mixtures using oil concentrations higher than 5%, 10% and 15% in mass. PMs were analysed at first based on mechanical properties which indicated a better concentration at 15% of MO. This article presents a study of MO influence on biodegradation behaviour of PM, which was composed of low-density polyethylene obtained from food bags and biopolymers (PB) obtained in market plastic bags. PM doped with different concentrations of MO was submitted to studies of mechanical, chemical, morphological and thermal properties and their biodegradation behaviour was evaluated. The concentration of 15% of MO increased the thermal resistance of PM, improved the biodegradation behaviour according to controlled and free tests and reduced its stiffness without a loss of important mechanical properties. The results of this work showed that MO influenced positively the biodegradation of the PM mixture by improving 30% of the degrading speed.
Keywords: Biodegradation; Moringa oleifera; biopolymers; polymers; vegetable oil.