Surface and thermal properties of UV-irradiated chitosan/poly(ethylene oxide) blends

Abstract

Abstract The influence of UV radiation, used as a sterilizing agent, on chitosan/poly(ethylene oxide) (PEO) blends has been studied with ATR‐FTIR spectroscopy, contact angle measurements, atomic force microscopy (AFM), polarized microscopy, and differential scanning calorimetry (DSC). The results showed that photooxidation process took place on the sample surfaces. The efficiency of this process increased with rising chitosan content in the blends and this process was most efficient for chitosan and the blend with 80% of this polymer. Both polymers in the blends revealed a mutual destabilizing effect. Changes in surface morphology, roughness and crystallinity of the samples caused by UV radiation depended on the blend composition. For chitosan and the blend with 80% of this polymer, subtle changes in the roughness parameters values were found and traces of the crystalline phase in the blend were destroyed due to efficient photooxidation. For PEO and the blend with 80% of this polymer, the roughness parameters values and the crystallinity degree increased after irradiation, possibly owing to photoetching. In the blends with 40–60% of chitosan, the roughness parameters values and the crystallinity degree decreased after UV treatment, which may result from the competing processes of oxidation and etching. These polymers can be used for preparing the biomaterials whose behavior under UV rays depends greatly on the blend composition and the crystallinity.