Comparative investigation of biological water retting and boiling-water extraction of Musa acuminata leaf blade fibers for potential bio-based composite applications

Abstract

The objective of this study was to compare the influence of biological water retting and boiling-water extraction on the chemical, physical, mechanical, and structural properties of Musa acuminata leaf blade fibers and to investigate their potential for incorporation into starch-based bioplastics. Fibers extracted by biological water retting (A) and boiling-water extraction (B) were characterized by chemical composition analysis, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), physical measurements, and tensile testing. The experimental data were subsequently analyzed using Student’s t -test. FTIR analysis confirmed that both fiber types are lignocellulosic materials composed mainly of cellulose, hemicellulose, lignin, pectin, and extractives. Water-retted fibers exhibited a higher cellulose content (46.10%) than boiled fibers (29.90%), whereas boiling-water extraction resulted in a higher lignin content. The crystallinity index increased from 48.95% for boiled fibers to 56.90% for water-retted fibers. Physical characterization showed linear mass values of 8.26 and 14.33 tex, densities of 1.29 and 1.39 g/cm 3 , water absorption capacities of 581.48% and 498.81%, moisture contents of 11.34% and 11.29%, and average bundle diameters of 264.03 and 249.77 μm for fibers A and B, respectively. Mechanical characterization demonstrated that biological water retting better preserved the mechanical performance of the fibers, yielding a Young’s modulus of 6.53 GPa, tensile strength of 175.56 MPa, and elongation at break of 2.80%, compared with 5.35 GPa, 129.03 MPa, and 2.58% for boiled fibers. Statistical analysis showed that the extraction method significantly affected cellulose content, crystallinity index, linear mass, density, water absorption, Young’s modulus, and tensile strength, whereas no significant differences were observed for moisture content, fiber bundle diameter, or elongation at break. Finally, starch-based bioplastic films incorporating fibers obtained by both extraction methods were successfully fabricated as a proof of concept. The composite films were not mechanically, physically, thermally, or morphologically characterized in the present study; therefore, their actual reinforcement performance remains to be experimentally established in future work.