Title
Sustainable films from water hyacinth cellulose: mechanical and thermal characterization of plasticized CMC
Authors
USARAT RATAKAMNUAN, NITTAYA KLANGPINIT and PRACHAYA NAMWONG

Received January 6, 2026
Published Volume 60 Issue 3-4 March-April
Keywords carboxymethylcellulose (CMC), Eichhornia crassipes, etherification, glycerol, propylene glycol, sorbitol

Abstract
Water hyacinth (Eichhornia crassipes) was utilized as an alternative lignocellulosic source for the preparation of carboxymethyl cellulose (CMC) and the fabrication of cellulose-based films. Microcrystalline cellulose (MCC) was isolated through alkaline delignification, bleaching, and acid hydrolysis, followed by carboxymethylation using monochloroacetic acid. The successful conversion of MCC to CMC was confirmed by Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) analyses, indicating the introduction of carboxymethyl functional groups and a transition from a semicrystalline cellulose I structure to a predominantly amorphous CMC phase. Solvent-cast CMC films exhibited good transparency and homogeneity but limited ductility. To modify the mechanical performance, glycerol (G), propylene glycol (PPG), and sorbitol (S) were incorporated as plasticizers at concentrations ranging from 0 to 20% (w/w). The addition of plasticizers significantly increased elongation at break, accompanied by reductions in tensile strength and Young’s modulus, reflecting enhanced chain mobility. Thermogravimetric analysis (TGA) revealed a moderate decrease in thermal stability with plasticizer incorporation. The results demonstrate that the mechanical and thermal properties of water-hyacinth-derived CMC films can be effectively tailored through plasticizer type and concentration, highlighting their potential as tunable cellulose-based film materials.