Study On Heat Generation And Thermal Conduction Of The Rubber Under Dynamic Compression Flex

Temperature rise which is determined by heat generation and thermal conductivity will damage Mechanical Properties and shorten the life of the materials. Therefore, it’s particularly important to study the heat generation and thermal conductivity of the materials under dynamic conditions. In this paper, SSBR/BR and NR was chosen as base materials. For SSBR / BR system, the effect of the filler loading, filler type, rubber content and CB/Silica on heat generation, thermal conductivity and dynamic mechanic property were investigated. The values corresponding to specific temperature and strain of the rubber blocks in compression flexometer experiment was used to calculate temperature rise in the center of the rubber block with temperature estimation formula. For NR system, the effect of vulcanization time, vulcanization temperature, vulcanization system and Anti-reversion agent on heat generation, thermal conductivity and dynamic mechanic property were investigated.The results indicate that as the temperature increases, the loss modulus G2, thermal diffusivity α and thermal conductivity λ decreases, the specific heat capacity Cp increases. For SSBR / BR system, With the increasing of carbon black loading、structure and decreasing of particle size, the loss modulus G2, thermal diffusivity α and thermal conductivity λ increases, the temperature rise increases. With the increase of the content of silica, the loss modulus G2 and the specific heat capacity Cp increases, thermal diffusivity α and thermal conductivity λ decreases, the temperature rise increases. With the decrease of the rubber content, the loss modulus G2, thermal diffusivity α and thermal conductivity λ increases, the specific heat capacity Cp decreases, the temperature rise increases. The predicted temperature rise in the center under steady-state calculated byT_max-T_w1=(T_w2-T（w1）/h²+2R²)+（3R²πε²₀fG’’）/4λ（h²+2R²）,were approached to practical testing values, The relative errors are within 10%, thus proving the rationality of the derivation of the equation from experimental perspective.The loss modulus G2 and specific heat capacity Cp are increased, the thermal diffusivity α, thermal conductivity λ and crosslink density of the vulcanizates are decreased after compression flex test. With the curing time and curing temperature increases, the crosslink density, thermal diffusivity and thermal conductivity decreases; loss modulus and specific heat capacity increases, the temperature rise increases. The longer the curing time, the higher the curing temperature, the smaller the change of this parameters after compression flex test. In the case of the same crosslink density, CV system has larger loss modulus, higher temperature rise and smaller change of this parameters after compression flex test. Adding anti-reversion agent PK900, the crosslink density, thermal diffusivity and thermal conductivity increases, the specific heat capacity decreases. And the change of this parameters after compression flex test decreases.