## 1 Introduction
In addition, both thermo-mechanical and morphological properties (flexural, damping at temperature interest of 80 \({}^{\circ}\)C) of chopped industrial hemp fiber-reinforced cellulosic plastic biocomposites have been improved, especially with 30% plasticized polar cellulose acetate plastic (CAP) [14]. Furthermore, the mechanical properties (tensile and flexural) of woven natural (banana) fiber with Musaceae/epoxy composite materials have been experimentally analyzed [15]. They obtained maximum values of stress and Young's modulus in both \(x\) and \(y\)-directions. An evaluation of the mechanical properties of natural coir fiber-reinforced epoxy composite has been similarly reported [16]. Their results indicated coir as a promising reinforcing fiber for producing low load bearing thermoplastic FRP composite. The nanoindentation technique is commonly used to analysis the surface properties of materials, such as coated surface [17]. It has been extensively used to evaluate the mechanical behavior of different polymers [18, 19, 20] and nano-composites [21, 22, 23, 24, 25, 26, 27, 28]. [PERSON] et al. [29] reported the influence of water ageing on nanoindentation response of the in situ components of hemp yarn/epoxy composites. Nanomechanical properties (hardness and elastic modulus) of layered silicate-reinforced unsaturated polyester nanocomposites was studied [23], using nanoindentation technique. They reported that the nanoindentation properties of the nanocomposites were enhanced, caused by clay reinforcement and the amount of clay dispersion within the unsaturated polymer resin. The nanomechanicalproperties (creep, hardness and elastic modulus) behavior of human hair using the nanoindentation and scanning electron microscopy (SEM) techniques was studied [30]. They reported that hair follicle recorded the greater hardness and elastic modulus than cortex at lateral direction, while the depth of indentation increased as both the elastic modulus and hardness of the hair decreased. Similar to this study, the mechanical properties of short flax fiber-reinforced polypropylene compounds were investigated [31]. Both strength and stiffness of the compound were achieved with the reinforcing flax fiber as well as effective compatible fiber-matrix interaction. Furthermore, mechanical, water absorption and thermal conductivity properties of hemp fiber reinforced polyurethane composites have been investigated [32]. The experimental result suggested a promising application of these sustainable composites in thermal insulation field, due to their improved mechanical properties. The thermo-physical properties of natural fiber (banana/sisal), hybrid pineapple leaf and glass fibers-reinforced polyester composites have been investigated [33]. The composite thermal contact resistance was reduced due to the chemical treatment of the fibers, while a significant improved heat transfer ability was achieved with the hybridised natural fiber with glass. The effects of phenylphosphate-based flame retardant on flammability, thermal stability and mechanical properties of glass fiber-reinforced epoxy (GRE) composites have been investigated [34]. The hardness and Young's modulus of the epoxy (EP) matrix was performed using a nanoindentation test. They reported that N'-diamyl-p-phenylphosphonicdiamide (P-MA) had no effect on the hardness of the EP matrix and the interfacial strength of glass fiber/epoxy matrix. In addition, some studies have been conducted on contact angle and surface energy analysis of different materials [6; 35; 36; 37]. For instance, the effect of fiber treatment and glass fiber hybridisation on thermal degradation and surface energy behavior of hemp fiber/unsaturated polyester (HF/UP) composites has been studied [6], using thermogravimetric analysis (TGA) and contact angle measurement. Their experimental results indicated the possibility of obtaining better thermal stability and wetting behavior of HF/UP composites with surface treatment and hybridisation techniques.