## 1 Introduction  
The potential for polymer composites reinforced with nanomaterials to drastically enhance mechanical, thermal, and functional properties has garnered substantial attention in recent years [1; 2; 3; 4]. Both synthetic and natural polymers serve as matrices in the development of these composites. Among natural polymers, natural rubber (NR) is particularly notable for its superior mechanical and thermal properties, especially in its vulcanized form [5; 6]. Its remarkable elasticity, resistance to wear and fatigue, and renewable nature have made it an indispensable material in many industries. However, its mechanical and thermal limitations in certain applications necessitate a search for advanced reinforcement techniques [7]. NR's exceptional properties have drawn interest from various technological and industrial sectors [8; 9; 10; 11; 12; 13]. There are more than 2000 types of plants that produce natural rubber (NR) latex; however, latex from the rubber tree (_Hevea brasiliensis_) is the most valuable due to its quality, production level, and economic aspects [14]. NR is composed of cis-1,4-isoprene isomeric units with a head-tail configuration. NR is one of the most widely used polymers due to its properties, such as elasticity, flexibility, and resilience [15]. Carbon nanotubes (CNTs) are among the leading nanomaterials for reinforcing polymer matrices due to their extraordinary mechanical, electrical, and thermal properties [16]. CNTs are self-assembled tubular structures consisting of carbon atoms arranged in hexagonal configurations. Their chirality, a term that refers to their atomic arrangement, governs whether they exhibit a metallic or semiconducting behavior. CNTs are generally categorized into single-walled (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) types [17; 18]. A SWCNT is a hexagonal tubular form of graphene. In SWCNTs, carbon atoms are arranged in a hexagonal lattice structure, which curls up into a cylindrical tube. Typical SWCNT diameters are in the range of 0.4 to 2 nm, and their unique properties are a result of two active sites, namely, the side wall of the tube and the end cap [17; 18]. On the other hand, MWCNTs are composed of 2 to 50 graphene sheets rolled cylindrically into various shapes, producing a slightly intricate structure with an outer tube diameter ranging from 2 to 30 nm and an inner tube diameter ranging from 0.3 to 20 nm [18; 19]. CNTs are characterized by extremely high surface areas, a high aspect ratio (length/diameter), and remarkably high mechanical resistance. In particular, the mechanical tensile strength of CNTs is 100 times greater than that of steel, and their electrical and thermal conductivities are comparable to those of copper [20; 21; 22]. Due to these unique properties, CNTs can be used to produce desirable consumer products by filling different polymers and ceramics. It is well known that MWCNTs possess high mechanical strength, excellent thermal and electrical conductivity, and a high surface-to-volume ratio, making them an excellent choice for reinforcing polymer matrices [23; 24]. As a result of the incorporation of MWCNTs into natural rubber, a composite with superior properties may be generated, which can be used in a range of industrial applications [25]. The combination of NR with CNTs stands out as a particularly promising research avenue. Recent studies have demonstrated that the addition of MWCNTs to NR-based nanocomposites can significantly improve their mechanical, thermal, and electrical properties. Surface modifications of MWCNTs have been shown to enhance adhesion to the NR matrix, resulting in superior reinforcement performance and improved thermal stability [26]. Depending on the concentration and dispersion of MWCNTs within the NR matrix, notable improvements in tensile strength, thermal stability, and conductivity have been observed [27; 28; 29; 30].