A Novel Natural Fibers-Based Bio-Composite Prepared From Silk Fibroin and Luffa Cylindrica

Abstract Herein, the novel bio-based co-polymer was synthesized using only natural fibers by way of co-dissolving cellulose extracted from luffa cylindrica (LC) and silk fibroin (SF) in formic acid in different weight ratios (3SF/1LC, 2SF/2LC, and 1SF/3LC). The prepared bio-composite films were investigated by vibrational, structural, thermally, and wettability with Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and water contact angle (WCA). The results of the FT-IR test reveal that the changing and shifting of peak intensities in spectroscopy of bio-composite films are evidence of the forming of new chemical bonds between luffa cellulose and silk fibroins. XRD results show that silk fibroin enhances the crystallinity of bio-composite specimens. In addition, thermogravimetric analysis demonstrates that increasing the cellulose ratio in bio-composite films extends their thermal stability of. The glass transition value provided by the DSC test proves that the flexibility of hybrid bio-composite films increases as the ratio of luffa increases. As a final analysis, WCA states that when blended with luffa and silk fibroin, although both are hydrophilic, the hybrid bio-composite films display hydrophobic properties, and also LC increase enhances this behaviour against water.