Study On The Application Of Eucommia Ulmoides Gum Composite In Engineering Tire Tread Compound

In recent years,with the vigorous development of the world’s mining industry and hydraulic engineering,the market demand for high-performance engineering tires has grown rapidly.As engineering tires are often driven in areas with poor road conditions,higher performance requirements are put forward for the tread rubber material directly in contact with the road surface,such as excellent fatigue resistance,low heat generation,cutting resistance,and wear resistance.Natural rubber(NR)has excellent comprehensive properties and is the best choice for engineering tire tread compounds,but my country’s natural rubber resources are limited and rely heavily on imports.Eucommia ulmoides gum(EUG)is a unique natural polymer material in my country.It has dual properties of rubber and plastic.When used together with NR,it can improve the physical and mechanical properties,fatigue resistance and cutting resistance of composite materials.It is expected to meet the performance of engineering tire tread rubber.demand and solve the problem of insufficient natural rubber resources in my country.In this paper,by designing the vulcanization system of NR and EUG,adjusting the crosslinking density and the combination ratio of the composite materials,the structure and properties of the combined rubber were studied,and a new compound with low heat generation,cutting resistance,wear resistance and fatigue resistance was developed.Engineering tire tread compound material.The main research contents and conclusions are as follows:The first part of the paper(Chapter 3)studies the co-vulcanization of NR and EUG.By examining the vulcanization characteristics,mechanical properties,peel strength,etc.of NR,EUG and NR/EUG composites under different accelerator systems,it was found that in the formulation system with DM as the accelerator,the mechanical properties of NR/EUG composites were the highest,and NR had the highest mechanical properties.EUG has the strongest peel strength and achieves the co-crosslinking effect.When the amount of accelerator DM is 1.25 parts,and the amount of sulfur is 2.5 parts,the overall performance of NR/EUG composites is the best.The second part(Chapter 4)studies the effect of NR/EUG composite ratio on the structure and properties of NR/EUG composites.Compared with the unfilled pure natural rubber,when the combined amount of EUG is less than 50,the addition of EUG can significantly improve the rolling resistance and fatigue resistance of the composite material.When EUG is used in combination with 50 parts,the first-order and sixth-order flexural times of the composite are 4.2 times and 5.4 times that of the pure natural rubber material;the physical and mechanical properties of the NR/EUG composite material are comparable to those of EUG in the composite material.The dispersion state and size of the composite are closely related.When the size of the EUG phase in the composite is small and the dispersion is relatively uniform,the dynamic compression temperature rise of the composite can be reduced,and the hysteresis can be reduced.The tensile strength and tear strength are improved,and the crack growth rate is reduced,which is related to the presence of eucommia gum microcrystals in the composite material.Through the infrared spectrum analysis of the NR/EUG composite material before and after fatigue,it is found that the fatigue failure of the composite material is a combination of mechanical damage and force.-The result of chemical interaction.The third part of the paper(chapter 5)studies the effect of different NR/EUG ratios on the properties of silica reinforced NR/EUG composites.It was found that with the addition of EUG,the loss factor(tanδ)of NR/EUG composites at 7%strain decreased significantly,that is,the rolling resistance decreased;with the increase of EUG content,the flexural resistance of NR/EUG composites improved significantly;and Compared with the pure natural rubber reinforced with silica,when the combined ratio of NR/EUG is85/15,the dynamic compression heat generation performance,cutting resistance and wear resistance of the composite material are obviously improved,and the overall performance is the best.At this time,the dynamic compression temperature rise of the composite material is 25.4°C,which is3.2°C lower than that of the pure natural rubber material,which is 28.6°C,and the dynamic compression temperature rise is reduced by 11.2%.The Akron wear volume of the NR/EUG composite is the smallest,with a wear volume of 0.26 cm~3,which is 10.3%higher than that of pure natural rubber.