A Novel Acrylic Acid-Schizochytrium Sp. Bio-Based Polymer: Design, Synthesis, And Properties

The innovative synthesis of a bio-based poly(acrylic acid) (PAA) and Schizochytrium sp. was performed for the first time. Schizochytrium sp. whole biomass (SCZ) and the insoluble cell fraction (cell wall) (FIP) were used as precursors for the synthesis of the copolymer. Infrared spectroscopy, thermogravimetry, and scanning electron microscopy were performed to determine copolymer formation, thermal properties, and morphology. The new hybrid biopolymers' thermal and mechanical properties were found to be dependent on microalgae biomass type and concentration. Transition temperature (T-g) of the hybrid PAA-SCZ biopolymers decreased when increasing microalgae percentage, while the opposite occurred for PAA-FIP. It was evaluated the maximum mechanical strength and elongation capacity of PAA-SCZ and PAA-FIP at room temperature and 50 degrees C. The elongation percentage of the obtained copolymer raised 2-7 times upon increasing the algal biomass concentration. Flexibility increased 3-4 fold when using FIP instead of SCZ. The entire biomass and the cell wall induced structural changes in the hybrid biopolymers similar to those observed in elastomers. A hydrolytic assessment revealed a high swelling capacity (30000 %) for PAA-SCZ hybrid polymer when exposed to physiological conditions (pH 7.4). In terms of these new properties, they can be suitable for biological and environmental applications.