Synthesis of nanocellulose from Solanum tuberosum peels and it’s aloe vera fibre-polyester composites: mechanical, DMA, fatigue and creep properties

The present research investigates the mechanical, fatigue, creep, and dynamic mechanical properties of Aloe vera-polyester-nanocellulose composites to evaluate their structural performance and reinforcement effects. The incorporation of Aloe vera fibers significantly enhanced the mechanical properties of the composite, with further improvements observed upon the addition of nanocellulose. Specimen PAN2, containing 3 vol% nanocellulose, exhibited the highest tensile strength of 131 ± 1.0 MPa, representing a 156.9% increase compared to the unreinforced specimen. It also demonstrated superior flexural strength of 148 ± 1.7 MPa, a remarkable 134.9% improvement over the baseline, and the highest impact resistance of 60.0 ± 8.7 KJ/m², confirming its ability to effectively absorb energy and resist fracture.The same composite also exhibited the highest tensile and flexural modulus of 8.9 ± 0.3 GPa and 9.8 ± 0.3 GPa, respectively. Additionally, PAN2 displayed the best fatigue resistance, with cycles to failure reaching 23,475 ± 1120 at 25% of UTS, 20,625 ± 990 at 50% of UTS, and 17,804 ± 880 at 75% of UTS, indicating its enhanced durability under cyclic loading due to optimal stress dispersion and reduced crack propagation. However, specimen PAN3, with 5 vol% nanocellulose, exhibited the best creep resistance, recording the lowest strain values of 0.0062 ± 0.0003 at 5000 s, 0.0071 ± 0.0003 at 10,000 s, and 0.0088 ± 0.0004 at 15,000 s, which highlights its superior ability to resist time-dependent deformation. PAN3 also demonstrated the excellent storage modulus of 5.2 ± 0.2 GPa and the highest glass transition temperature of 91 ± 3 °C in the dynamic mechanical analysis, confirming its superior stiffness and thermal stability. The SEM analysis further provided insights into the micrpscopic morphology, where the plain resin matrix exhibited voids, while fiber pull-out was evident in the fiber-reinforced specimen. PAN2 displayed improved filler-matrix adhesion, contributing to its superior mechanical properties, whereas PAN3 exhibited agglomerated nanocellulose particles, which, despite acting as stress concentrators, contributed to its high creep and thermal resistance.