Study On Properties Of EPDM/NR Reclaimed Rubber Compounds

The effects of curing system, mixing technology and compatilizer on propertiesof EPDM/NR reclaimed rubber compounds were studied in this thesis.The current study indicates that EPDM/NR reclaimed rubber blendingvulcanizates would have the best mechanical properties with the amount of sulfur of2.5, At this time the vulcanizates tensile strength, and modulus, tear strength,hardness are up to maximum. Peroxide system, when the DCP content is3.5,EPDM/NR reclaimed rubber blending vulcanizates would have the best mechanicalproperties. it was found that the tensile strength of the EPDM/NR reclaimed rubbervulcanizates were improved with declining of carbon black particle size andincreasing of their specific serface area,its tensile strength of5.2MPa increased to11.9MPa. But when the carbon black particle size is too small,the particles easilyagglomerate because of the increasing of particles flocculating power.In this case,mixing dispersion becomes difficult. Physical and mechanical properties willdecrease. When using five kinds of carbon black reinforcement, the reinforcementeffect of carbon black N330is the best. EPDM/NR reclaimed rubber Blendingvulcanizates showed the best overall performance with the amount of Carbon Black50phr.As the unsaturation of EPDM decreased, the mechanical properties ofEPDM/NR reclaimed rubber Blending vulcanizates decline. After hot air aging, asthe third monomer content decreases, aging resistance of vulcanizates improved.Appropriate blend ratio can give a good rubber processability and mechanicalproperties. When the blend ratio of NR reclaimed rubber/EPDM is30/70, the blendscan achieve good co-vulcanization. Blends of particle dispersed more uniformly, andthe blend vulcanizates have the best physical and mechanical properties. Differentways of blending have different effects on EPDM/NR reclaimed rubber vulcanizates.Blending vulcanizates have different physical and mechanical properties. EPDMmasterbatch and reclaimed natural rubber blends have short curing time and can achieve good co-vulcanization. At this time, Blending vulcanizates showed the bestoverall performance.When the Chlorosulfonated polyethylene (CSM), methacrylic acid zinc (Zn(MAA)2) and coupling agent KH-845-4added to the EPDM/NR reclaimed rubberblend, vulcanization rate and vulcanization degree and the compatibility of theblends will improve. When the content of CSM, KH-845-4were30and2respectively, the blend vulcanizates have the best physical and mechanicalproperties.