Effect of Teff Straw (Eragrostis Tef) Based Microcrystalline Cellulose on Enhancement of Thermo- Mechanical and Microstructural Properties of PVA Bio-Degradable Polymers

This study investigated the potential of microcrystalline cellulose (MCC) fibers, isolated from Teff straw (TS) using a chemical treatment with metal catalysts, as reinforcement for polyvinyl alcohol (PVA) films. The effects of MCC type (derived from different metal catalysts) and loading (0, 2, 5, and 8 wt%) on the physico-mechanical properties (including thermal stability) of PVA films, were investigated. The incorporation of MCCs significantly improved the films’ mechanical strength. Compared to neat PVA, the tensile strength increased by up to 49%, 71%, and 67% when incorporating Cr(III)-MCC, Fe(III)Cl-MCC, and Fe(III)-MCC, respectively, at a 5% loading level. The thermal stability of the PVA/MCC composites also improved, with a higher onset degradation temperature compared to neat PVA. For instance, The T_onset for the neat PVA, Cr(III)-MCC, Fe(III)Cl-MCC, and Fe(III)-MCC-based PVA films were 295, 305, 308, and 303 ⁰C at a level of 5% MCC content, respectively. Scanning electron microscopy (SEM) analysis revealed good dispersion of MCC fibers within the PVA matrix, indicating strong interaction between the materials. Overall, TS MCCs show promise as low-cost, bio-based reinforcement for producing biodegradable films with enhanced mechanical properties and thermal stability, making them suitable for various applications like food packaging.