Studies On The Key Factors Affecting The Modulus Stability Of Tire Compounds

Compared with foreign tires,poor modulus stability during the period of service is a major challenge for domestic tires,because it has important impacts on the driving performance,durability,service life and safety of tires.The strain of the tire is usually less than 20% during the actual active time.Therefore,the methods to determine the modulus under small strain are compared and discussed first.Based on analyzing the changes in the internal network structure of the compounds under small strain,the effects of the filling system and vulcanization system on the stability of 20% modulus(M20)are studied in detail,to provide the theoretical and practical guidance for the preparation of tire compounds with high modulus stability.Three different instruments,universal electronic tensile machine(Zwick),dynamic mechanical property analyzer(DMA,static tensile mode),and dynamic mechanical property analyzer(DMTs,10Hz),are used,respectively,to measure the modulus changes under 0-60% strain.The results show that obtained modulus curves have good reproducibility with the smallest standard deviation by using DMA in the static stretching mode,with tensile rate being 50mm/min.The changes in internal network structure of the tire compounds under small strain are analyzed by DMA in a cyclic stretching mode.When the strain is less than 10%,the increase of strain mainly leads to the destruction of carbon black aggregates,resulting in an almost linear decrease in the modulus;when 10%