Use of sunflower seed fried oil as an ecofriendly plasticizer for starch and application of this thermoplastic starch as a filler for PLA

The high cost of the Poly(lactic) Acid when compared to its durable competitors is a significant drawback that inhibits its diffusion for many industrial applications. A common solution is the compounding with other polymers that preserve biodegradability, and thermoplastic starch (TPS) is a conventional choice. The innovation proposed in this work is to replace into the starch plasticization process part of the glycerol with a sunflower seed oil resulting from the frying process in a fast food. The so plasticized TPS was compared to the TPS plasticized with only glycerol and then mixed to the PLA. The replacement of a certain percentage of glycerol with fried edible sunflower oil as plasticizer for starch results in an improvement in material properties of the TPS and does not change the properties of the PLA/TPS blends. Plasticization of starch with fried oil has been proven to be the most environmentally sound solution also from a Life Cycle Assessment.