## 1 Introduction  
Cellulose is the most abundant natural polymer in the world. Due to the demand for biodegradable and renewal materials caused due to threats such as global warming and plastic pollution, there has been a tremendous interest during the past decade in biocomposites derived from cellulose and thermoplastic polymers [1]. From an engineering materials perspective, celluloses form the major load bearing component in wood cell walls with high strength of about \(\sim\)3 GPa and a potential modulus \(\sim\)138 GPa with respect to the longitudinal direction [2]. Extensive research and a number of publications on the terms cellulose and biocomposites have increased drastically in recent years [3]. Many cellulose reinforced composites have potential applications in the automotive component industry, construction and packaging [4; 5; 6]. This is due to the sustainability, availability, low density, high specific strength and stiffness of natural fibers which can be compared to that of glass fibers [7; 8; 9]. To date, almost 50% of a vehicle's internal parts are made out of polymeric materials and the global average weight of plastic in a modern day passenger vehicle is 105 kg accounting for 10-12% of the vehicle weight [4]. As government regulations and automotive makers are trending towards fuel economy, high efficiency, and cleaner ways of operating with reduced CO\({}_{2}\) levels, the demand for biocomposites is expected to increase [10; 11]. Cellulose fibrils impart improvement in dimensional stability and physical and thermal properties of the cellulose reinforced biocomposites and have excellent potential as a reinforcement material for thermoplastic composites because of their mechanical properties and low thermal expansion coefficient [12]. Few studies have been published examining the natural fibers reinforced polyamide-6 (PA6) composites preparation through the injection molding technique for the automotive industry [13]. Natural fiber reinforced composites are mainly confined to commodity or standard polymers such as polyolefins due to the challenges of high processing temperatures [10; 14; 15; 16]. Commonly, polypropylene (PP), polyethylene (PE) and polyoxethylene are reinforced with natural short fibers and subsequently reveal excellent mechanical properties but these polymers habitually require coupling agents such as maleic anhydride grafted polypropylene (MAPP) and/or dispersing agents such as diglyme, during their preparation processes, respectively [17; 18; 19; 20]. Biobased polymer like polylactic acid (PLA) has also been studied as a matrix for natural fibers reinforcement, but PLA-natural fiber composites exhibit poor adhesion at the fiber-matrix interface. Various studies have indicated a decrease in the final properties of the PLA-natural fiber composite and, moreover, have given the thermal characteristics of PLA, it tends to degrade in some compounding processes such as repeated extrusion [21; 22; 23]. Engineering polymers such as polyamides are in exigency in the automobile industry accounting to their eco-friendly nature. Recent studies emphasizing on increasing the properties of polyamides reinforced with cellulosic materials are promising for our study [24; 25]. Polyamide-11 (PA11) would be an obvious choice of matrix to work on, as 100% bio-based PA11 is commercially available and many investigations published are successful in obtaining composites with high mechanical properties [24; 26]. However, polyamide-6 (PA6) or nylon-6 is a more attractive engineering polymer provided that PA6 is competing with thermoset plastics and metals for \"under the hood\" automotive applications due to their resistance to high temperature, oils and corrosive chemicals, relative strength to weight ratio and recyclability [16].