PLA/Coffee Grounds Composites: A Study of Photodegradation and Biodegradation in Soil

Biodegradable polymers are an alternative to replacing petroleum‐derived polymers. This work aimed to incorporate coffee grounds (CG) in different contents (5 and 15 wt%) as an accelerator of the biodegradation process to reduce the degradation time of poly (lactic acid) (PLA). The use of this natural source filler can minimize environmental problems, due to its low cost and easy access, since this waste is produced in large quantities. Thus, biodegradable composite can be produced with the use of CG as filler in the PLA matrix. PLA/CG composites are processed using a thermokinetic homogenizer (DRAIS), followed by hot pressing. The samples are subjected to accelerated degradation (ultraviolet radiation – UV) and biodegradation in soil and later are characterized by the percentage of weight loss, visual analysis, morphology by scanning electron microscopy (SEM), thermal analysis (differential scanning calorimetry – DSC) and mechanical properties (Izod impact test). After the biodegradation tests and analysis, it is possible to verify improvements in the mechanical properties of the developed composite, as well as the desired biodegradative effects.