Purpose <p>This study investigates <i>Cyanodon dactylon</i> as a sustainable resource for cellulose extraction and its modification into cellulose acetate (CA), aiming to develop eco-friendly bio-polymeric films. The research focuses on evaluating the efficiency of cellulose isolation, acetylation, and the structural and mechanical properties of CA-based composite films.</p> Methods <p>Cellulose was isolated from <i>Cyanodon dactylon</i> using sequential alkaline pulping, yielding 31.98% cellulose content, including 27.3 wt% α-cellulose. The extracted cellulose underwent rapid acetylation via transesterification with vinyl acetate in DMSO, completing within 5&#xa0;min. CA was then blended with polyvinyl alcohol (PVA) to fabricate bio-polymeric films through solvent casting. Characterization techniques, including FT-IR, XRD, ¹H-NMR, TGA, and chemical saponification, were used to assess the structural, thermal, and morphological properties. Mechanical testing evaluated the films’ strength and flexibility.</p> Results <p>FT-IR spectra confirmed successful acetylation, while XRD analysis showed reduced crystallinity correlating with the degree of substitution. ¹H-NMR and titrimetric methods validated the degree of acetylation. The CA-PVA films demonstrated a balance between structural integrity and porosity, with slightly reduced tensile strength and elongation at break. The substantial α-cellulose content and efficient CA synthesis highlight <i>Cyanodon dactylon</i>’s potential as a renewable material source.</p> Conclusion <p>This study establishes <i>Cyanodon dactylon</i> as a viable, sustainable resource for eco-friendly material production. The successful synthesis of cellulose acetate and its application in bio-polymeric films promote environmental sustainability and economic viability, contributing to green material innovation.</p> Statement of Novelty <p>This research presents a novel approach to the sustainable synthesis of cellulose acetate (CA) from <i>Cyanodon dactylon</i>, a widely available and underutilized plant resource, for bio-based polymeric film applications. The study introduces a rapid transesterification process that achieves cellulose acetylation within just 5&#xa0;min, significantly reducing reaction time compared to conventional methods. Comprehensive characterization using advanced analytical techniques confirms the structural and thermal modifications, emphasizing the successful integration of CA into PVA matrices for bio-composite films. This work highlights <i>Cyanodon dactylon</i> as a promising, renewable feedstock for the development of eco-friendly materials, offering an innovative pathway for valorizing biomass while contributing to sustainability and circular economy goals in polymer science.</p> Graphical Abstract <p></p>