Synthesis and characterization of plasticized films from synthetic and natural polymers: Effects of plasticizer type

The synthesis of plasticized films represents a promising research area in materials science. In this study, films were produced using natural polymers linseed mucilage (LM) and chitosan (CH), with poly (acrylic acid) (PAA), plasticizers (PL) sorbitol (S), glycerol (G), ethylene glycol (EG) and polyethylene glycol (PEG). The films were fabricated via the casting method using V-50 as the initiator, and the four plasticizers. It was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Mechanical properties were also evaluated. The resulting plasticized films were uniform, flexible, and translucent with amber coloration. FTIR analysis confirmed chemical interactions involving C–H, C O, CH–OH, and C–O functional groups present in LM, CH, the PLs, and PAA. TGA revealed strong thermal stability, with decomposition resistance maintained between 116 and 423 °C. Additionally, the incorporation of S and PEG contributed to a reduction in the glass transition temperature (Tg). Tensile testing demonstrated the influence of PL content on the mechanical performance of films. As PL concentration increased, the films became less rigid and more ductile. Both Young’s modulus (YM) and tensile strength (TS) decreased with increasing PLs content, whereas elongation at break (%EL) increased. The films exhibited TS values of 8.7–34.2 MPa and YM values of 0.15–2.6 GPa. Notably, higher PL concentrations resulted in lower YM and TS values; however, %EL increased substantially, ranging from 2.7% to 146%. The highest %EL values were obtained for the film with the LM/CH/PAA/PL ratio of 2.0/2.0/18/3.0 wt/wt.