Mechanical and Physical properties of chitosan and whey blended with poly(ε-caprolactone)

• Published in: International journal of polymeric materials 2002, Vol.51 (3), p.275-289
• Main Authors: Olabarrieta, I., Jansson, A., Gedde, U. W., Hedenqvist, M. S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Blends; Chemistry; Chitosan; Exact sciences and technology; Kemi; Mechanical properties; NATURAL SCIENCES; NATURVETENSKAP; Optical Properties; Organic polymers; Physical Properties; Physicochemistry of polymers; Poly(ε-caprolactone); Properties and characterization; Whey
• ISSN: 0091-4037; 1563-535X; 1563-535X
• DOI: 10.1080/00914030213038

Properties important for packaging were studied on blends of 0-15 wt% poly( l caprolactone) and chitosan and a whey-protein-isolate. The blends were obtained by solution mixing, and films were produced by solvent casting. Transparency was measured by UV/VIS spectroscopy and the printability was qualitatively estimted by using a red ethanol dye. Mechanical properties of solid films and seals were assessed by tensile tests. Stiffness and folding endurence were also measured. The blend morphology was characterized by scanning electron microscopy. It was found that all the blends were transparent. The whey-protein-isolate had the best printability properties and printability remained in the poly( l -caprolactone)-blends. Film stiffness decreased and strain at break increased strongly when the pure chitosan and the pure whey-protein-isolate were wetted. The addition of poly( l -caprolactone) to chitosan and whey-protein-isolate had only a moderate effect on the toughness properties but a strong effect on the modulus which could be predicted by the Halpin-Tsai model. The modulus of the whey-protein-isolate increased and the modulus of the chitosan decreased with the addiion of poly( l -caprolactone). It was found that it was impossible to seal chitosan with a standard heat-pulse sealing technique. The whey-protein-isolate was sealable but the strength of the seals was lower than the intrinsic strength of the pure whey-protein-isolate. The folding endurance properties of chitosan and its blends were far better than those of the whey-protein-isolate and its blends.