Innovative materials based on physical melt-blending of cutin from tomato waste and poly(lactic acid)

In the last decades, the improving and the progresses achieved following the principles of circular economy have unveiled virtuous approaches towards environmental challenges regarding the industrial processes. Agri-food waste constitutes a promising starting material for the design of innovative products with a marked improvement of the cradle-to-grave dynamics. In this scenario, the recovery of cutin from tomato peels waste represents an effective example of circular economy. In this work, the feasibility of the discontinuous melt-blending of cutin with poly(lactic acid) (PLA) was evaluated in order to obtain an innovative green material. Different blends of PLA and cutin have been characterized by using a multi-technique approach (FT-IR, DSC, TGA, SEM, rheological study, water vapour permeability) to achieve information on the nature and properties of these new materials. An important decrease of the final torque of the melt blends was observed, together with a decrease of the melt viscosity. Further increase in the cutin content in the blends was associated to a change in the viscosity of the melt. The addition of cutin to the PLA matrix caused a variation in the water vapour permeability, in accordance with the hydrophobic nature of the cutin. The obtained results attested that some degradation phenomena occurred along the process; however, the processability of these new blends is not impaired. The potential applications of these materials will mainly concern the agricultural sector and the production of degradable products with low environmental impact.