Use of Waste Red Seaweed Furcellaran for Development of Green Thermoplastically Processable Bioplastics

Bioplastics are in focus for the development of sustainable materials due to the depletion of fossil resources, generation of solid waste and global climate change. Considering this, the current research is devoted to the valorization of beachcast red seaweed F. lumbricalis for the development of thermoplastically processable bioplastics. The composites have been developed from beachcast red seaweed-derived furcellaran (FUR) and potato-derived thermoplastic starch (TPS) by using an ultrasound-assisted technique. Three different FUR concentrations (10, 30 and 50 wt.%) in relation to potato starch were examined for their thermoplastic processability. Fourier infrared spectroscopy (FTIR) was used to reveal the structural changes in the developed TPS/FUR composites depending on FUR content as well as thermal pre-treatment. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and tensile mechanical tests were performed to assess the performance of the developed TPS/FUR composites. It was demonstrated that the ultrasound-assisted manufacturing route allowed TPS/FUR composites with an improved spectrum of properties to be obtained. The highest mechanical stress at break (almost three times higher than for neat TPS) was observed for the TPS + 50 wt.% FUR composite, which also possessed decreased deformability (only ca 10%), reduced thermal resistance at processing temperatures (150 °C) and high shear sensitivity. Thus, the TPS + 30 wt.% FUR and especially the TPS + 10 wt.% FUR composites were recognized as more suitable for thermoplastic processing and the development of TPS-based composites with improved exploitation properties.