Natural rubber from different Hevea braziliensis clones, namely RRIM600, RRIT251, PB235 and BPM24, exhibit unique properties. The influences of the various fresh natural rubber latex and cream concentrated latex on the non-rubber components related properties were studied. It was found that the fresh natural rubber latex exhibited differences in their particle size, which was attributed to the non-rubber and unique signature of clones which affect various properties. Meanwhile, the cream concentrated latex showed the protein contents, surface tension, and color of creamed latex to be lower than the fresh natural latex. However, TSC, DRC, viscosity, particle size and green strength of concentrated latex were found to be higher than the fresh natural latex. This is attributed to the incorporation of HEC molecules. Also, the rubber particle size distribution in the RRIM600 clone exhibited a large particle size and uniform distribution, showing good mechanical properties when compared to the other clones. Furthermore, the increased green strength in the RRIM600 clone can be attributed to the crystallization of the chain on straining and chain entanglement. These experimental results may provide benefits for manufacturing rubber products, which can be selected from a suitable clone.

Novel composite based on rubber and modified bentonite clay (Clay) was investigated. The modified bentonite clay was developed by dispersing in ethanol solutions (Et-OH) using ultrasonic method. The effect of Et-OH on the dispersion of bentonite clay at various mixing temperatures in case of different type of rubber matrix, i.e., natural rubber (NR), epoxidized natural rubber (ENR25, ENR50) on dynamic mechanical rheology, Payne effect, XRD and mechanical properties of rubber composites were studied in detail. The bentonite clay dispersion in Et-OH at a mixing temperature of 80 °C improves the intercalation and exfoliation in rubber chains. Bentonite clay is highly intercalated in ENR 50-Clay composite, which can be confirmed from its superior mechanical properties. The results indicated that sonication of bentonite clay in Et-OH improves the interlayer spacing of bentonite clay by partial intercalation of rubber matrix.

The shape memory (SM) polymers with superior SM properties were successfully fabricated based on melt blending of natural rubber (NR) and ethylene octene copolymer (EOC) at various crystallinity of EOC phase. The differential scanning calorimetry analysis, mechanical properties, temperature scanning stress relaxation, and shape memory properties were studied. Results revealed that the mechanical and thermal properties of the prepared NR/EOC blends improved as a function of amount of ethylene fraction in the EOC phase. The ethylene segment of EOC in the NR/EOC blend is triggered as a stimulus-sensitive domain. The shape memory properties in terms of shape fixity and shape recovery efficiencies of the blends tended to increase with the increasing of crystalline segments in the blends. The shape memory properties of the prepared blends substantially exceed the best performance (close to 100%) by blending the NR/EOC at 50/50 parts by weight, having 62%–80% of ethylene content in the EOC phase, which corresponds to approximately 3°–16° of crystallinity of EOC phase in the blends.

Vulcanized latex films from different Hevea brasiliensis natural rubber clones, including RRIM600, RRIT251, and PB235, were prepared using the creaming process of concentrated latex. The protein content, morphology, molecular weight distribution (MWD), mechanical properties, dynamic mechanical analysis, and thermo‐mechanical properties were studied. The morphological characteristics of the Hevea brasiliensis natural rubber clones were analyzed using transmission electron microscopy (TEM). The results indicated that the particle sizes of the three clones ranged from 1.0 to 2.5 µm. Moreover, the MWD exhibited a bimodal pattern in the RRIM600 and RRIT251 clones, leading to a high polydispersity index (PDI) that correlates with protein content. Additionally, the PB235 clone showed higher molecular weight (Mw) than the other clones, which affected the properties of the vulcanized latex films. The mechanical properties, dynamic mechanical properties, thermal properties from temperature scanning stress relaxation (TSSR) analysis, and swelling resistance were also studied. The results indicated that the crosslinked density of the vulcanized latex films is related to the bimodal MWD. This leads to increased physical interactions between the end chains of short and long rubber molecules. Moreover, the crosslinked density is associated with protein content. This study confirms that the MWD and non‐rubber components in different natural rubber clones affect the properties of vulcanized rubber.

This study focused primarily on the relationship between mesostructure and the final vulcanizate performance of solid natural rubber (NR) derived from three Hevea brasiliensis clones: RRIM600, RRIT251, and PB235. The evaluated mesostructural characteristics included molecular weight (Mw), polydispersity index (PDI), molar mass distribution (MMD), and protein content. The RRIM600 and RRIT251 clones exhibited a bimodal MMD and a broad PDI, which correlated with their higher protein content. Notably, the RRIM600 clone demonstrated superior mechanical properties, including 500% modulus (5.21 MPa), tensile strength (27.19 MPa), tear strength (27.38 N mm ⁻¹ ), and rebound resilience (73.30%). It also showed enhanced thermal–mechanical stability, with a T90 of 213.5°C determined via temperature scanning stress relaxation (TSSR). Furthermore, the physical relaxation peaks in the TSSR spectrum were found to be strongly related to the protein content of the NR. Dynamic mechanical thermal analysis (DMTA) also revealed higher storage and loss modulus for RRIM600, indicating superior elasticity. Conversely, the PB235 clone displayed a unimodal MMD and the highest M _w , signifying longer macromolecular chains that resulted in higher initial plasticity, minimum torque, and elongation at break. Overall, this research provides crucial insights for selecting appropriate NR clones to manufacture high‐performance rubber products.