## 3 Results and Discussion
### WSR of the Vulcanizates  
Vulcanizates with different content of M-DCPD resin were obtained after curing at 160 \({}^{\circ}\)C. They are named as R0, R2, R4, R6 and R8, representing composites with M0, M2, M4, M6 and M8 added, respectively. Using dynamic mechanical properties at low temperature to evaluate the WSR is accepted by most researchers in that deformation hysteresis is considered as one of major routes to dissipate energy under either the high frequency or low temperature [13,20]. The internal dissipation, i.e., tan\(\delta\) was then accordingly measured. As shown in Figure 4, the value of tan\(\delta\) at 0 \({}^{\circ}\)C increases with increasing MAH content and then drops. R4 presents the maximum value, indicating the best performance of R4 in WSR. However, adding M-DCPD resin slightly influences the rolling resistance of the vulcanizates according to the variation in tan\(\delta\) values at 60 \({}^{\circ}\)C.  
The effect of resin on tan\(\delta\) is closely related to the compatibility between resin and rubber compounds, which results from the changes of glass transition temperature. The closer the peak value to 0 \({}^{\circ}\)C, the better improvement of the wet skid resistance of the vulcanizates [23]. Figure 4 shows that with increasing MAH content in the M-DCPD resins, the T\({}_{\text{g}}\) of vulcanizates increases from \(-17.5\)\({}^{\circ}\)C to \(-11.7\)\({}^{\circ}\)C, values of tan\(\delta\) at 0 \({}^{\circ}\)C increases from 0.51 to 0.58 as well. The WSR performance of R8 was limited by inferior solvability of M8 in the rubber compounds due to its high glass transition temperature. For high hysteresis, two vital requirements are: (1) existence of filler aggregates; (2) destruction and reconstruction of filler agglomerates under dynamic stress [11]. Figure 5 visualized the supposed interaction mechanism of the modified resin with silica. The AR calculated above demonstrates that the polarity of resin increases with increasing amount of MAH, resulting in enhanced interaction between polar resin and silica, which can relatively weaken the filler-filler interaction. Furthermore, the interaction makes it more susceptible for filler aggregates to be damaged and reconstructed under periodic strain. For agglomerates containing trapped rubber, the destruction facilitates the release of restricted polymer chains, which exactly adds more energy consumption forms, leading to significant increase in loss modulus at low temperature (0 \({}^{\circ}\)C) and further in hysteresis. Although extended rubber volume fraction by released rubber chain enhanced viscidity, elastic modulus of vulcanizates increases as the polar interaction enhanced due to addition of M-DCPD resin, resulting in the decline of peak value of tan \(\delta\) of R8 at glass transition zone. Figure 4: Stress strain curves (**a**), tan\(\delta\) values at 0 \({}^{\circ}\)C and 60 \({}^{\circ}\)C (**b**) of the vulcanizates. Figure 5: Schematic of the interaction between modified resin and silica. However, the above two cases predict consecutively increased tan\(\delta\) values at low temperature as MAH content increasing, which does not completely correspond to the experimental results. Therefore, we suppose that the effect of M-DCPD resin on dynamic performance dose not only relate to the strength of the interaction with silica, but also relates to its dispersion in the rubber matrix. Resin would interact with only limited parts of filler aggregates if it cannot uniformly disperse in the rubber compound, leading to less effective improvement on hysteresis. That is likely to be the reason why the tan\(\delta\) value of R8 is significantly lower than those of R4 and R6. On the whole, M-DCPD resin remarkably enhances energy consumption by interacting with silica.