The synergistic effect of 1-butyl-3-methylimidazolium chloride and glycerol on the performance of chitosan films

In this study, we examined the plasticizing effects of 1-butyl-3-Methylimidazolium Chloride (BmimCl), glycerol, and their combination on chitosan (CS) films. Additionally, we examined the effect of plasticizers for chitosan films structure and physicochemical properties of CS films by FTIR, XRD, SEM and mechanism of action of plasticizers on the structure of CS films. The results indicated that the interaction between BmimCl and chitosan is mainly ionic interaction and hydrogen bonding, while the interaction between glycerol and CS is mainly hydrogen bonding. The utilization of a 1:1 mixture of BmimCl and glycerol as a plasticizer exhibits a synergistic impact on the film samples. In dry conditions, the elongation at break of the CS/BmimCl 0.5 /Gly 0.5 film reached 17.47 %, representing a 33 % and 78 % increase compared to the CS/BmimCl and CS/Gly films, respectively. In moist environments, the mechanical strength of CS/BmimCl 0.5 /Gly 0.5 film was significantly enhanced to 35.09 MPa compared to the CS/BmimCl and CS/Gly films. Notably, the elongation at break of the films remained at 37.05 %, without compromising their flexibility properties.