# Mechanism and Characterization of
## 2 Results
### Rheological Properties  
DMA provides insight into the mechanical response of rubber materials under various operating conditions, especially under dynamic loading. Rubber composites are commonly used in applications such as automotive tires, shock absorbers, and seals, where the materials are subjected to complex loading conditions. DMA is an important tool for studying the properties of materials under these complex conditions. Figure 2a shows the storage modulus of NNR, SNR, MNR, and MSNR at different temperatures. It is evident that the storage modulus of MSNR is higher than that of NNR, SNR, and MNR, indicating that the dual-component fillers improved the dispersion of the fillers within the NR matrix, enhancing the internal cohesion and interfacial bonding capabilities of NR. This contributes to extending the service life of NR and reducing deformation-related damage during use. Figure 2b presents the loss modulus of the four composites. Compared to NNR, SNR, and MNR, MSNR exhibits a higher loss modulus, indicating better filler dispersion and enhanced interfacial interactions within the NR matrix. Figure 2c illustrates  
Figure 1: Mechanical properties of NNR, MNR, SNR, and MSNR: (**a**) stress–strain curve, (**b**) tensile strength, (**c–f**) stress–strain hysteresis curves. the loss factor of the four composites, with MSNR showing the lowest loss factor, suggesting that the dual-component fillers enable efficient energy storage and recovery within the NR matrix, resulting in better elastic behavior under dynamic deformation. This also indicates that it maintains good elasticity at low temperatures, thus preventing material embrittlement and making it suitable for low-temperature environments. MSNR has good energy absorption and vibration damping properties, demonstrating that it has a good resistance to deformation. Specific DMA properties are shown in Table S3. Tg1, Tg2, Tg3, and Tg4 represent the glass transition temperatures of NNR, MNR, SNR, and MSNR, respectively. It is evident that Tg4 shifts significantly to the right, which is due to the introduction of dual-component fillers that reduce the mobility of NR, restrict the free movement of NR chains, and lead to stronger interfacial bonding [30; 31]. Specific rheological property ratios are shown in Table S2. The dispersion performance of MNR and MSNR was evaluated using a rubber process analyzer (RPA). Figure 3a shows the storage modulus of the three composites under strain. It is evident that all three composites exhibit a decreasing curve as strain increases, which is due to the destruction of the internal crosslinked network structure of the composites--a phenomenon known as the Payne effect [32]. The Payne effect is a significant non-linear change in the modulus of elasticity of a rubber or other polymer-based composite materials when a load is applied. This phenomenon is particularly evident in rubber matrix composites and is often used to describe the effect of the dispersion state of the filler on the properties of the material. In the case of tires, the Payne effect has an important influence on the nonlinear properties exhibited by the material under load. The nonlinear stiffness of the material can affect the traction, fuel efficiency, and wear behavior of the tire. A lower Payne effect indicates that the filler is more uniformly dispersed in the rubber matrix, forming fewer aggregates or agglomerated structures. This is due to the lower interaction force between filler particles, which avoids the localized increase in stiffness due to aggregation, thus reducing the dynamic modulus of the composite. The value of \(\Delta\)G' = G' (10.47%) \(-\) G' (95.35%) was used as a standard to evaluate dispersion, where \(\Delta\)G' represents the difference in G' between a 10.47% strain and 95.35% strain. A larger \(\Delta\)G' value indicates more severe filler agglomeration in the matrix [32].