Thermal, mechanical and absorption properties of cellulosic films filled with nanoclay

The extensive use of petroleum-based polymers has exacerbated environmental pollution and fossil fuel depletion, spurring global interest in eco-friendly alternatives. Biodegradable materials serve as a potential replacement for non-biodegradable polymers. Among them, Cellulose, a prevalent natural biopolymer, having emerged as a promising material due to its affordability, biocompatibility, and biodegradability. However, cellulose alone have poor properties, therefore modification may be reequired. Recent research investigated the preparation of cellulose and Montmorillonite (MMT) clay films using the ionic liquid 1-ethyl-3-methylimidazolium acetate as a solvent. The study is aimed to evaluate the impact of MMT on the mechanical, absorption, and thermal properties of cellulose films. The results indicated that incorporating MMT significantly improved the films' moisture and water absorption properties. Moisture absorption decreased from 15.73 wt% to 8.55 wt%, and water absorption reduced from 22.68 wt% to 9.15 wt% as MMT content increased from 0% to 3%. Additionally, the water contact angle increased by approximately 54%, suggesting reduced hydrophilicity due to enhanced interaction between cellulose and clay particles. Differential scanning calorimetry (DSC) revealed that the glass transition temperature of the cellulose films increased with MMT loading, peaking at 89.447 ℃ with 3% MMT. While crystallization temperature remained unchanged or decreased, tensile stress and modulus improved with increased MMT content, achieving a maximum tensile strength of 32.06 MPa and modulus of 1.53 GPa at 3% MMT. The thermal stability of the films also enhanced, with a maximum improvement of 35.6% in thermal stability at 3% MMT loading. In conclusion, the research demonstrated that cellulose/MMT nanocomposite films, produced via solvent casting with EMIMAc, exhibited notable improvements in mechanical, absorption, and thermal properties due to effective cellulose-MMT interactions.