## 1 Introduction  
The rise of the fibre-reinforced composites business in the automobile industry has triggered a search for environmentally friendly natural resources. Due to their numerous benefits to engineering construction, composite materials have been widely employed in transportation applications for decades, replacing traditional metals [1]. The lower-weight features of composite materials are particularly intriguing in transportation applicationssince they may reduce energy consumption. Composite materials, in addition to being lighter than steel, provide several other advantages [2]. Steel has lower fatigue resistance than composite materials. This feature has made composite material utilization in structural applications more appealing. Despite their various benefits, composites are primarily made of artificial fibres such as graphite, glass, and fibreglass. This situation negatively influences climate change since synthetic fibres are not recyclable. Lignocellulose fibres are being employed to substitute artificial fibres in composite goods, perhaps making them more ecologically friendly. Natural fibres may be better for the environment than synthetic materials [3]. Natural textiles also provide several advantages over synthetic fabrics, including superior characteristics, low cost, low density, lower power consumption, and are ecologically friendly, non-abrasive, non-toxic, and long-lasting [4]. The significant advancement in the mechanical features of sisal-based polymer matrix composites was considered remarkable amongst the numerous natural fibre mixtures. Sisal fibre, derived from the Agave sisalan tree, is one of the most frequently used natural materials and can be quickly grown in any region of Earth. It comes from the sisal plant. According to the global context, the rate of sisal fibre production is expanding due to its wide range of uses [5]. Hybrid composites comprise more than two fibres in a unified framework. By addressing distinct mixtures' defects, hybridization can improve the mechanical properties of biological-fibre-reinforced polymers [6]. Flaxseed (_Linum usitatissimum_ L.) represents the only intensive agriculturally significant plant in the Linaceae category, including four groups with 400 varieties. Flaxseed, the very first textile formed from grains and solidified into such matrices, was grown from around 5000 B.C. and also unearthend in Egyptian tombs. It is one of the most commonly used bio-fibres [7; 8]. Flax has been a critical crop for decades due to its uses in filaments and petroleum. Flaxseed has undergone extensive research and development for favourable features such as herbicide resistance, biogenic drought tolerance, higher oil content, and cellulose qualities. Flaxseed is a perennial tree, having 16-32 mm branches that develop to 0.5-1.25 m in height [9]. In flaxseed cultivation, natural plants are much more effective in low sites, where ambient abiotic stresses induce considerably more morbidity than in rich soils [10]. Moreover, it has been shown that lignocellulosic fibre-based composites exhibit little nick compassion compared to artificial composites. Organic filament-strengthened composites have some benefits over synthetic fibre composites but also have certain disadvantages. The hydrophilic characteristic of cellulosic fibres makes them incompatible with polymeric matrixes, which is one of their primary weaknesses [11]. Because of their hydrophilicity, lignocellulosic materials absorb many environmental moistures. On the other hand, chemical approaches can improve the fibre-polymer matrix interaction. Natural materials are often pre-treated before being used in composites to improve their interactions and produce high mechanical strength. The surface properties of the filaments are altered during treatment, resulting in a heavily cross-linked interfacial region with covalent bonding connections between the reinforcement and the matrix.