New Filler And Hybrid Modification With Carbon Black And Silica And Application In Rubber

As a novel filler,the silica fume is a powder recovered from flue gas of alloy smelt,with silica dioxide as main component.In this paper,the characteristics of silica fume were briefly analyzed,and the performance of NR filled with silica fume and with N330 was compared.Meanwhile,the influence of silica fume dosage on the processing performance,physical and mechanical properties and dynamic properties of tire tread and sidewall were investigated.The application prospect of silica fume in green tires was discussed.In addition,the silica/silica fume hybrid filler was prepared.The effect of hybrid filler obtained by different methods on the properties of the rubber compound was studied.The results showed that,both SF1 and SF2 silica fume were smooth spheres with large particle size and low surface activity.The ability of silica fume to form bound rubber was much lower than that of carbon black N330.Therefore,the tensile strength and tear strength of NR vulcanized rubber filled with silica fume was lower than that of N330 filled.However,the vulcanizate had higher resilience and lower dynamic heat build-up.Silica fume,hybridized and combind with carbon black or silica,was applied to tire tread and sidewall.It was found that some properties of vulcanizate such as tensile strength and wear resistance decreased.At the same time,the addition of silica fume improved processing properties,reduced dynamic heat build-up,improved wet skid resistance and reduced rolling resistance.So,silica fume could partially replace the carbon black or silica in the tire rubber without reducing the performance of the rubber compound appearantly,but achieve the purpose of improving processing performance and reducing the overall cost.In the silica/silica fume hybrid filler,the silica particles partially covered the surface of the silica fume and connected the fume particles together.Compared with the compound filled with the dry co-hybridized filler,the compound filled with the wet co-hybridized filler had better processing performance and the Payne effect was weaker.At the same time,vulcanizate had better wear resistance,lower temperature rise,excellent wet skid resistance and low rolling resistance.Compared with the compound filled with HB200/SF2 hybrid filler and the compound filled with 1165MP/SF2 hybrid filler,the former had weaker Payne effect and better processing performance and the vulcanizate had higher tensile strength,tensile stress and hardness and lower dynamic heat build-up,while the latter had better processing safety,wear resistance and wet skid resistance.