## 1 Introduction
Alkali pre-processing is one of the most used pre-treatment methods for changing the surface morphology of fibres and dissolving high lignin content, waxes, and impurities [12; 13]. During the alkaline chemical modification, the hydroxyl groups of lignocellulosic materials are ionized particles with an alkoxide. The hydrophilic character of the filaments is concentrated and the reinforcement-resin interaction is improved. Furthermore, chemically processed organic filaments have been demonstrated to exhibit improved fibre-dispersal capabilities, resulting in increased stress transmission across the fibre-matrix interaction due to the reduced quantity of hydrophilic groups in the fibres [14]. In the current world of materials and industrial engineering, nanoparticle-reinforced polymers are one of the most reliable and well-known composites for constructing models [15; 16]. When nanocrystals are used for reinforcing, several investigations have shown that the synthetic behavioural properties improve more than the mechanical characteristics. Aluminium oxide is another essential ingredient employed for reinforcements due to its exceptional electromagnetic, structural, and thermodynamic characteristics. It has the breadth of a single organism and a multi-dimensional hexagonal strategy. It has been used in many electronic and optical devices [17]. Due to its endurance, it has now been proven to be an excellent filler in epoxy restoration materials. The existence of an oxide position in nano-aluminium material, which acts as a strong adhesive throughout the matrix, is also the leading cause [18]. Implementing green techniques to produce nanoparticles is becoming an active issue in nanotechnology. Because of its numerous uses in physics, economics, physiology, and healthcare, work on synthetic nanoparticles and their characterization has been a developing subject of nanotechnology for the last twenty years [19]. Natural nanoparticle manufacturing techniques based on microbes, enzymes, fungi, and flowers derived from plants were proposed as ecologically sound replacements for chemical and physical approaches. Manufacturing nanoparticles using plants or plant components might sometimes be beneficial over other biological methods because it eliminates the complex procedures of sustaining bacterial culture [20]. Since Al\({}_{2}\)O\({}_{3}\) NPs were chemically bio-inert and hydrogel was more durable, they have received exceptional interest in the leading edge of specialized development in the synthesis and development of contemporary antibacterial drugs with sustainable biological properties. Many researchers have already addressed the bioavailability of Al\({}_{2}\)O\({}_{3}\) NPs ceramics. Highly pure Al\({}_{2}\)O\({}_{3}\) NPs are also the first Phyto commonly used in clinical applications and it was suggested that the life of Al\({}_{2}\)O\({}_{3}\) NPs is greater than that of the people affected [21,22]. As a result, Al\({}_{2}\)O\({}_{3}\) NPs could be used in various fields, including structural ceramics catalysis, textiles, wastewater, and protein isolation. Furthermore, Al\({}_{2}\)O\({}_{3}\) NPs have many biological uses, including biosensing, Phyto, and therapeutic agents [23]. Because of its eco-friendly character and non-harmful approach, green systemization hugely influences today's and tomorrow's societies. Plant leaves were formerly used to make nanopowders such as SiO\({}_{2}\), TiO\({}_{2}\), and Al\({}_{2}\)O\({}_{3}\). The aluminium oxide (Al\({}_{2}\)O\({}_{3}\)) nanofiller utilized in the method is extracted from the 'Neem Leaf' using a specific ratio of aluminium nitrate. The main objective of the investigation is to find the effectiveness of fibre and nanoparticle weight % in the mechanical and moisture absorption behaviour of sisal/flax-based hybrid composites. The compression moulding technique was used to fabricate the hybrid composites. After fabrication, the composites were tested for various mechanical properties such as tensile, flexural, and impact.