Harnessing a byproduct from wastewater treatment to obtain improved starch/poly(vinyl alcohol) composites

[Display omitted] •Lipid-based by-product was used in starch/ poly(vinyl alcohol) composite synthesis.•A new recovering method for fat traces from wastewater was developed.•Methacrylated linseed oil and visible radiation were used for water treatment.•Thermal, mechanical and water resistance for the new composites were investigated.•The application of the new composites could be considered in agro-industrial domain. A rational method to harness a triglyceride-based by-product containing chicken fat traces, extracted from the simulated slaughterhouses wastewater was adopted. Methacrylated linseed oil was used as photo-reactive monomer to “catch” the grease molecules, resulting in a polymeric network (PFrec), further embedded in starch/poly(vinyl alcohol) (St/PVA)-based composites, with or without plasticizer (glycerol-Gly), with enhanced properties. Hydrophobic additive improved the thermal stability of St/PVA blends, an 18 ⁰C increase of Td3 % being registered for PFrec-loaded sample. Mechanical tests revealed that association of PFrec with Gly improved the flexibility and also reinforced the systems, although, no plasticizing effect was observed at PFrec addition. Solubility determinations for the St/PVA-based composite films showed that hydrophobic PFrec increased the water resistance with at least 40 %. According to contact angle measurements a good dispersion of PFrec in the St/PVA network was mediated at the interface by hydrophilic Gly molecules.