A Novel Bio-based Polyaspartic Acid Copolymer: Synthesis, Structure and Performance of Degradation

A novel bio-based polyaspartic acid copolymer, as a multifunctional polymer was fabricated via in-site melting polymerization method using l-aspartic acid, -aminobutyric acid, l-phenylalanine and l-alanine as raw materials. The synthetic conditions were studied in detail, and the structure and degradation assays of these copolymers were investigated by FT-IR, XRD, weight loss rate, pH values, intrinsic viscosity and SEM. According to the results, all of the copolymers were found to have similar structure and excellent degradability. Additionally, the optimized copolymer C7 [l-aspartic acid (0.45mol), -aminobutyric acid (0.35mol), l-phenylalanine (0.05mol) and l-alanine (0.15mol)] exhibited the highest weight loss rate among all the copolymers. The weight loss rates on the 28th day in aqueous medium, phosphate buffered saline solution, 5.0wt% trypsin solution and soil culture medium reached up to 44.74wt%, 99.75wt%, 90.67wt% and 83.58wt%, respectively. And the appropriate introduction of bio-based amino acids could control the degradation of polyaspartic acid distinctly. All of these results indicated that the bio-based polyaspartic acid copolymer could be used for reference as a good understanding of description the degradation of other environmentally friendly bio-based polymers.