Effect Of Storage And Remilling Technology On Condensed State Structure And Extrusion Rheological Behavior Of SSBR/BR Compounds

The study focused on the SSBR/BR compounds,investigated the effect of storage time?storage temperature and remilling times on condensed-state structure and extrusion rheological behavior of CB filled compounds and CB/CNT filled compounds by means of capillary rheometer?RPA?rubber extruder ?SEM and several other Analytical instruments.Through the bound rubber?strain sweep and SEM research,we can find that with the extending of storage time or rising of storage temperature,the interactions between carbon black particles and rubber chains are increasing,the agglomeration degree among carbon black particles is aggravated,the entanglement CNT itself and CNT with rubber chain are aggravated.With the increasing of remilling times,rubber chains are break,the interactions between carbon black particles and rubber chains are decreasing,the breakage degree of carbon black aggregates is increasing;CNTs get some level short through mechanical effect,the entanglement CNT itself and CNT with rubber chain are decreasing.Under the same condition,the content of bound rubber of CB filled rubber compounds is higher than CB/CNT filled rubber compounds,due to the reinforcing mechanism of CNTs' entanglement.With the extending of storage time,the Mooney viscosity?shear viscosity?die swell ratio and entrance pressure loss of the two rubber blends are increasing,the two rubber compounds extrude through “Garvey”die,the“zigzag” flaw at the 30 degree corner of the extrudate are aggravating.With the rising of storage temperature,the Mooney viscosity and shear viscosity of the two rubber compounds are increasing,the die swell ratio and entrance pressure loss of the two rubber blends increase at first,than become stable until the temperature reach 30 ?.At 20 ?,the“zigzag” flaw of the two rubber blends is lightest.With the increasing of remilling times,the Mooney viscosity and shear viscosity of the two rubber compounds are decreasing,the die swell ratio and entrance pressure loss of the tworubber compounds decrease at first,than become stable until the remilling times reach 10.Remilling times cause less influence on the apparent appearance of extrudates of the two rubber compounds.Under the same condition,compared with CB filled rubber compounds and CB/CNT filled rubber compounds,the viscosity of CB/CNT filled rubber compounds is higher,the die swell ratio of CB filled rubber compounds is bigger,the extrudates of CB/CNT filled rubber compounds is more smooth.The reason is related to the condensed-state structure of CB or CB/CNT.Through the study,we can find that the addition of 3phr CNT improve the extrusion rheological properties of the rubber compounds,but there is nothing to do with the storage time?storage temperature and remilling times.As for the two rubber compounds,the best storage time is 24 h,the best storage temperature is 20?,the best remilling times is 5-10.