Effects of Geomaterial-Originated Fillers on Microstructure and Mechanical/Physical Properties of α- and β-Chitosan-Based Films

• Published in: Molecules (Basel, Switzerland) Switzerland), 2021-12, Vol.26 (24), p.7514
• Main Authors: Mourak, Abdellah, Hajjaji, Mohamed, Alagui, Abdelhakim, Martin, Patrick, Joly, Nicolas
• Format: Article
• Language: English
• Subjects: Ammonia; Analytical chemistry; Biodegradation; Chemical Sciences; Chitosan; Chitosan - chemistry; chitosan-based films; Civil Engineering; Clay - chemistry; Eco-conception; Electrostatic properties; Engineering Sciences; Fillers; Food Packaging; Functional groups; geopolymer; Geopolymers; Infrared spectroscopy; Material chemistry; Materials; Mechanical properties; mechanical/physical properties; microstructural characterization; Microstructure; Montmorillonite; Organic chemistry; Packaging; palygorskite; Particle Size; Physical properties; Polymers; Porosity; Steam - analysis; Tensile strength; Thermal analysis; Thermal stability; Water absorption; Water vapor; Wettability
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26247514

Edible films and coatings with good mechanical/physical properties are highly required for carrying medical substances and food packaging. So, solvent-cast films of α- or β-chitosan filled with palygorskite, montmorillonite or geopolymer-containing material (GCM), were prepared, and the effects of their clay contents (up to 50 wt.%) on the mechanical/physical properties were assessed. The microstructure of the films was investigated using FT-IR spectroscopy, SEM and thermal analysis. The results showed that, except for the films composed of GCM and β-chitosan, the mechanical properties of the films with limited (up to 5 wt.%) to moderate (5-25 wt.%) amounts of fillers increased as a result of the attractive electrostatic forces formed between the fillers and chitosan functional groups (-NH , CH OH and NHCOCH ). However, due to the occurrence of coarse aggregates, the strength of filler-rich films declined. The addition of fillers led to an increase in porosity and water absorption of the films, but it had irregular effects on their wettability and water vapor transmission rate. These observations as well as the thermal stability of the films were discussed in relation to the characterization results.