title: The influence of UV-irradiation on thermal and mechanical properties of chitosan and silk fibroin mixtures.
abstract: In the present paper the results regarding the influence of UV-irradiation with 254 nm wavelength on the thermal and mechanical properties and the intrinsic viscosity of chitosan/silk fibroin mixtures are presented. The mixture of chitosan and silk fibroin in solution and thin films made of chitosan/silk fibroin mixture obtained by solvent evaporation were submitted to the treatment with UV irradiation (wavelength 254 nm) for different time intervals. Mechanical properties of thin films made of chitosan/silk fibroin blends before and after UV-irradiation have been investigated by mechanical testing machine and compared with mechanical properties of chitosan films. The changes in such mechanical properties as ultimate breaking strength, percentage of elongation at break and Young Modulus have been investigated. The results have shown, that the mechanical properties of the blends were greatly affected by time of exposure to UV irradiation. Ultimate tensile strength and ultimate percentage of elongation decreased after UV irradiation of the blend. Increasing UV irradiation led to the decrease in Young's Modulus of the chitosan/silk fibroin blend. Viscosity of chitosan/silk fibroin mixtures decreased after UV-irradiation. Thermal properties of the mixtures have been only slightly altered by UV-irradiation.
authors.affiliation: Nicolaus Copernicus University, Faculty of Chemistry, Biomaterials and Cosmetics Department, ul. Gagarina 7, 87-100 Toruń, Poland. Electronic address: as@chem.umk.pl.
authors.forename: Alina
authors.initials: A
authors.lastname: Sionkowska
authors.affiliation: Nicolaus Copernicus University, Faculty of Chemistry, Biomaterials and Cosmetics Department, ul. Gagarina 7, 87-100 Toruń, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Płanecka
authors.affiliation: Nicolaus Copernicus University, Faculty of Chemistry, Biomaterials and Cosmetics Department, ul. Gagarina 7, 87-100 Toruń, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Lewandowska
authors.affiliation: Nicolaus Copernicus University, Faculty of Chemistry, Biomaterials and Cosmetics Department, ul. Gagarina 7, 87-100 Toruń, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Michalska
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D055119:Elastic Modulus; D005349:Fibroins / Q000737:chemistry*; D055595:Mechanical Phenomena; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays; D014783:Viscosity
chemical_list: D005349:Fibroins; D048271:Chitosan
keywords: Chitosan; Mechanical properties; Photodegradation; Photooxidation; Polymer mixtures; Silk fibroin; Thermal properties; UV-irradiation