Analysis And Improvement Of Microscopic Defects In Rubber Materials

Fatigue failure of rubber materials easily caused safety accident under dynamic conditions.The microscopic defects inside the material were the main reason.Explored the causes of microscopic defects in rubber materials and took corresponding improvement measures,it has important theoretical and engineering significance for improving the performance and service life of rubber products.Therefore,this paper firstly analyzed the rubber compound of the tire shoulder part which was prone to fatigue damage to confirm the cause of the micro-defect,then improved defect of rubber material from the formulation,process and application of new materials.It provides an important theoretical guidance for the fatigue resistance and the improvement of the service life of rubber products.Firstly,the defects of the selected domestic tires were analyzed by scanning electron microscopy(SEM).It was found that the dispersion of fillers,the accumulation of residual zinc oxide,and the uneven precipitation of protective wax were the main reasons.The dispersion of zinc oxide in vulcanizate was studied by SEM and fatigue life test.The effects of zinc oxide properties,zinc oxide varieties and mixing process on the uniformity of zinc oxide dispersion were analyzed.The results showed that: the larger of zinc oxide primary particles and aggregate particle size,the worse the dispersibility in the rubber matrix,leading to a lot of micro defects that has larger size;selected the appropriate mixing process can reduce the size of zinc oxide aggregate particles and microscopic defects.but the magnitude of the improvement depends on the nature of the zinc oxide itself.Secondly,effects of different kinds of protective wax on the fatigue properties of the rubber compound were studied.The results showed that,the dispersion and migration speed of the protective wax in the rubber compound had a great influence on the properties of the rubber material,The dispersion of the Rhine wax was relatively uniform in the rubber compound,the wax film was relatively dense,so it has excellent ozone and fatigue resistance;the microcrystalline wax type G has the best effect at high temperature protective;the new physical antioxidant polyolefin can replace microcrystalline wax,and surface of the rubber was always clean,it has good ozone and fatigue resistance.Adding polyolefin with a smaller molecular weight has better fatigue properties.Finally,in order to improve the dispersibility and reactivity of zinc oxide,a highly active elastomer-supported zinc oxide particle was successfully prepared by adsorption phase reaction technology.and elastomer was added to the rubber act as a multifunctional high active auxiliary to replace zinc oxide,vulcanizate has good physical-mechanical properties and fatigue resistance.