Development of Biodegradable Films Using Polysaccharides Extracted from Ulvaintestinalis: A Comparative Study of Plasticizers

Abstract

This study explores the preparation of biodegradable films from the green algae Ulva intestinalis, a rich source of sulfated polysaccharides. Extraction procedures employed comprised both microwave-assisted extraction (MAE) and aqueous acidic extraction with citric acid and hydrochloric acid. On safety grounds, the MAE procedure was abandoned in favor of mild thermal extraction under acidic conditions. The solution was subsequently screened with various plasticizers—glycerol and polyethylene glycol (PEG)—in concentrations between 30% and 70%, with and without citric acid as a crosslinker. The film-forming behavior, physical state, and stability were screened under controlled drying conditions. The results indicated that the formulations at 70% Ulva content with citric acid crosslinking, particularly in combination with 30% glycerol, showed the highest potential for producing elastic, semi-solid films. This thesis offers new knowledge on sustainable biofilm formation and establishes important parameters for the optimization of polysaccharide-based biodegradable package materials.