Riboflavin as a Biodegradable Functional Additive for Thermoplastic Polymers

With continuous development of biodegradable polymers, new areas of applications are intensively researched. Modifications of these polymers are commonly conducted by an extrusion compounding process. While additives are changing desired properties, biodegradability of such composites can be deteriorated. The aim of the work is to investigate a novel, functional, organic additive, riboflavin (vitamin B-2), in terms of thermal stability, extrusion processability, wettability, surface energy, especially biodegradability, and when compounded with PLA. Additionally, a comparison of unmodified PLA resin, as well as PLA-modified with inorganic talc—which is known for its nucleation promotion in a variety of polymers—to PLA with riboflavin, was presented. Research reveals the outstanding thermal stability of riboflavin and the sufficient extrusion process properties with no significant changes of wettability and, surprisingly, a significant degradation rate as compared to pure PLA or and PLA with talc. The obtained results do not exclude further modifications of PLA depending on the target application, e.g., antimicrobial agents, flame retardants, etc.