Study on the effect of co‐plasticization of post‐industrial starch for high‐impact thermoplastic starch development

Abstract This study analyzed the effect of employing plasticized or co‐plasticized post‐industrial starch in developing PBAT‐based thermoplastic starch (TPS) blends. In this work, the post‐industrial wheat starch was co‐plasticized with glycerol‐urea, glycerol‐citric acid, and glycerol‐succinic anhydride, and then melt‐extruded with PBAT to develop the TPS blends. The effect of co‐plasticization was investigated by analyzing the TPS blends' mechanical, thermal, and rheological characteristics. The results showed that co‐plasticized starch was more effective than solely glycerol‐plasticized starch in enhancing the TPS blends' mechanical, thermal, and rheological characteristics. The TPS containing citric acid as a co‐plasticizer showed increases of 246, 35, and 46% in impact strength, elongation at break, and crystallinity, respectively, compared to glycerol‐plasticized starch‐based TPS. Morphological analysis further revealed that the citric acid co‐plasticized starch improved the dispersion and compatibility of the plasticized starch within the PBAT matrix. Overall, the study showed that adding citric acid during the co‐plasticization of starch resulted in high‐impact TPS blends with enhanced material properties compared to glycerol‐plasticized starch and urea or succinic anhydride co‐plasticized starch.