Investigation On Flex Fatigue Resistance Properties Of Ssbr

The flex fatigue resistance properties of 6 types of SSBR with different microscopic structures including SSBR-T2003, T2530, T2000R, T1534, C2557A, C2564A were investigated based on fundamental formula of SBR. Effects of microscopic structures, carbon black contents, silica contents and processing aids on the flex fatigue resistance properties before and after hot air aging were respectively investigated. Studies were focused on correlations between the static and dynamic mechanical properties and flex fatigue resistance properties.The results showed that the flex fatigue resistance properties were influenced by different microscopic structures of SSBR greatly. For the six SSBR, The larger oil-filled volume was, the better the performance of flex cracking resistance was. With the increase of 1,2structure contents, the flex fatigue resistance properties were improved clearly. The effects of carbon black and silica contents on the flex fatigue resistance properties were great. With the increase of carbon black and silica contents the flex fatigue resistance properties first increased and then decreased. The flex cracking resistance properties of C2564A filled with 30phr carbon black or 15phr silica were better. By Scanning Electron Microscope (SEM), the flex cracking surfaces of vulcanizates filled with carbon black or silica were divided into three types, including soft fracture, soft and weak; ductile fracture, ductile and strong; rigid fracture, hard and brittle. The addition of processing aids could improve the flex fatigue resistance properties of vulcanizates filled with carbon black or silica. The flex fatigue resistance properties of vulcanizates filled with TT100 were best.The flex fatigue resistance properties were affected by hot air aging greatly. In the processing of hot air aging, G'of C2557A and C2564A increased with the increase of aging time, while G'of T2003, T2000R, T1534 and T2530 decreased. The flex fatigue resistance properties were worse after the hot air aging for the six SSBR, which C2557A and C2564A had little change. The flex fatigue resistance properties were worse after the hot air aging for vulcanizates filled with carbon black or silica.Correlations between the static and dynamic mechanical properties and flex fatigue resistance properties were studied preliminary. The results showed that whether or not to hot air aging, the flex cracking resistance properties of SSBR with different microstructures increased as the increase of ratio of tensile strength and cubic of hardness (T/H3) and ratio of tensile strength and damping factor (T/D). Whether or not to hot air aging, the flex cracking resistance properties of C2564A filled with different carbon black contents increased as the increase of T/H3 and T/D. When the differences of T/H3 or T/D were large, we could use T/H3 and T/D to forecast flex fatigue life of SSBR.