Recycling of poly(lactic acid)/poly(butylene succinate) (PLA/PBS) blends with high amounts of secondary raw material

Abstract

In this study, the mechanical recycling of poly(lactic acid)/poly(butylene succinate) (PLA/PBS)-based formulations with additives was investigated. A simulation of mechanical recycling was performed using secondary raw materials in the analyzed formulations (at very high levels >30%). The recycling process was simulated by repeating extrusion cycles on the compound to produce aging under accelerated conditions, similar to those that normally occur during the extrusion compounding of the bioplastic material. The formulations were characterized by using differential scanning calorimetry (DSC), heat deflection temperature (HDT), melt flow rate (MFR), Fourier transform infrared spectroscopy (FTIR) and UV–vis spectroscopy. The aim of the work was to study the efficiency of a multi-epoxy chain extender in mechanical recycling of PLA/PBS blends. The results showed that the use of secondary raw materials did not cause drastic changes in the thermal properties and chemical composition of the blends, which indicates that they are suitable for manufacturing bioplastic blends. Specifically, MFR results showed a major efficiency of the chain extender in samples having PLA as primary polymeric phase, whereas no change was observed in formulations where PBS is the main phase with the addition of a higher amount of chain extender.