| In this paper,we adopted two dynamic testing methods to investigate the dynamic fatigue evolution of adhesion of rubber/polymer cords from different aspects respectively. The first was a self-developing method, which can monitor the process of dynamic fatigue evolution all the time, revealing the mechanism of adhesion failure. Using this method, we investigated the influence of stress-controlled mode, strain-controlled mode and the fatigue frequency on the fatigue evolution of adhesion and adhesion life. We obtained the calculating formula of adhesion life to predict the actual life of the tire, which has a certain guiding significance. Another is to use the Demattia fatigue method to study the influence of the number of fatigue under high temperature and different fatigue temperature on the evolution law of adhesion. In addition, the effect of the sulfur dosage on the dynamic adhesion properties of rubber/polymer cord was investigated with the combination of two kinds of testing methods. Moreover, the study of dopamine used in the field of adhesion between rubber and polymer cords had been carried out in the preliminary stage. We investigated the feasibility of dopamine used for adhesion areas in three aspects respectively: dopamine adding in rubber, dopamine modifying the polymer cord and the preparation of a new type of dipping system using dopamine.The results showed that the MTS dynamic fatigue test was an effective way to test the dynamic fatigue evolution of adhesion of rubber/polymer cords. The fatigue evolution of the adhesion included three stages: the creep or stress relaxation of rubber; the accumulation of microcosmic damage; the acceleration of adhesion failure, respectively. Under stress-controlled mode by MTS, the adhesion life declined with the rising stress amplitude and the two meet a certain nonlinear relationship. Under strain-controlled mode, the adhesion life declined with the rising strain amplitude and it complied with different linear laws under lower and higher strain amplitude and the threshold value was 87.8%.We also found that when the frequency was low(≤7Hz),the adhesion life had nothing to do with the frequency under stress-controlled mode. Under high temperature(100℃)using Demattia fatigue, the adhesion force increased at first and declined subsequently with the rising fatigue number and it was the highest at the 400,000 fatigue number. At a certain fatigue number, with the rising temperature, the adhesion force showed a tendency of rising.With the increasing of the sulfur content, the static adhesion strength of rubber/nylon cords composite showed a linearly rising trend. However, the results of the two dynamic fatigue methods differed. The process of fatigue evolution of adhesion prolonged and the adhesion life showed a linear increase with the increasing of sulfur content under MTS tensile fatigue mode. But when the sulfur content was high, the formation of the hard and brittle interface layer was easily damaged under Demattia flexural fatigue.Dopamine using in rubber can increase the static adhesion strength of rubber/polyester cords obviously, and can even achieve the effect of HRH adhesion system. But the dynamic adhesion properties were poor. Dopamine modifying polyester cords can also improve the static adhesion strength and it rose with the increase of processing temperature. Dopamine using for preparing the new type of dipping system can improve the adhesion effect between rubber and various polymer cords significantly and the coverage of rubber on pulled-out cords also increased. But the attached rubber was more concentrated in the grooves between fibers, suggesting that this increase was attributed to the physical effects. |
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