| Silica is currently the most used reinforcing agent in the rubber industry after carbon black.The composite material made of silica-filled rubber has excellent high and low temperature resistance,aging resistance and good elastic properties,and is widely used in vehicles,instruments,aviation and other fields.Such materials are often used in high temperature,high pressure and other conditions,and temperature has an impact on their performance.Therefore,it is of great significance to study the temperature dependence of the mechanical properties of silica-filled rubber composites and their application in engineering.In this paper,in order to ensure the stability and consistency of the experimental materials,white carbon black was prepared by an improved precipitation method as the experimental raw material,and the modifier KH-570 and KH-550 were used to covalently modify the white carbon black.The rubber composites were prepared by the melt blending method,and the performance changes of the silica-reinforced natural rubber with different fractions of silica and the differences in the performance of the silica-reinforced rubber composites modified with different modifiers were experimentally studied.Finally,the temperature variable was controlled to conduct uniaxial tensile experiments on the silica rubber composite material in the range of 150% deformation,and the stress-strain relationship in the temperature range of 298-398K was studied.Finally,the Mooney-Rivlin mechanical constitutive model was used for fitting,and the Mooney-Rivlin constitutive model with significant temperature parameters was constructed.Research indicates:(1)Silica was modified with silane coupling agent(KH-570,KH-550).Comparative analysis found that the hydrophobic effect after modification was significantly higher than that before modification,and it was found that silica modified with KH-570 Compared with the silica modified with KH-550,its weight loss rate is lower,indicating that KH-570 can obtain a better modification effect.(2)The Silica/NR composite was prepared by the melt blending method.When the filler content was increased from 0 phr to 20 phr,the tensile strength and tear strength of the rubber composite increased in a certain proportion.However,when the proportion of silica is increased from 40 phr to 60 phr,the performance of the rubber composite is limited by the agglomeration characteristics of silica,which will have a negative impact in the rubber matrix and reduce the cross-linking density of the rubber composite to a certain extent.,So as to reduce the viscoelasticity of the rubber,increase its abrasion,and reduce its abrasion performance.In summary,using unmodified white carbon black as a filler and filling a 20 phr composite material has the best overall performance.The silica/natural rubber composite materials modified by adding silane coupling agents KH-570 and KH-550 were prepared by the same preparation method,and the modified silica was selected as the filler to reinforce the rubber composite material.The performance has improved.Moreover,comparing the two experimental composite materials,it once again proves that the performance of the composite material modified by KH-570 is better.(3)Based on the experimental data,through fitting and analysis with the Mooney-Rivlin model,it can be concluded that the Mooney-Rivlin model has a good predictive effect on the mechanical behavior of the rubber model under working conditions where the deformation does not exceed 150%.Analyze the correlation between the model parameters and the experimental temperature,and use the phenomenological theory to construct a Mooney-Rivlin mechanical constitutive model with temperature parameters.The model can reasonably predict the mechanical behavior of rubber composites within a certain temperature range. |
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