| In this paper,a new type of high-performance thermoplastic elastomer SEBS/PP TPVs which new polyolefin elastomers SEBS and polypropylene?PP?were selected as the research objects.1,3?1,4?-bis?tert-butylperoxyisopropyl?benzene?BIBP?/sulfur?S?was selected as a vulcanization system,was prepared by dynamic vulcanization.The influences of processing techniques such as processing temperature,rotor speed,blending time,rubber-plastic ratio,plasticizer systems such as naphthenic oil and paraffin oil,and filler reinforcement systems such as kaolin,calcium carbonate,mica powder,carbon black,and white carbon black on the mechanical properties,aging resistance,rheological properties and microstructure of SEBS/PP TPVs were discussed.Through the investigation of SEBS/PP TPVs processing technology,it was found that the tensile strength of the material increases first and then decreases with the increase of processing temperature and the time of dynamic vulcanization blending,and gradually increases with the increase of the rotor speed,the elongation at break of the material first decreases and then increases with the increase of processing temperature,and gradually increases with the delay of the dynamic vulcanization blending time,the tear strength of the material first increases and then decreases with the increase of processing temperature,and gradually decreases with the increase of the rotor speed and the extension of the dynamic vulcanization time.Considering all the properties of SEBS/PP TPVs,it was determined that the processing temperature was 180?,the rotor speed was 100 r·min-1,and the dynamic vulcanization blending time was 4 minutes.By investigating the effect of the amount of cross-linking agent BIBP on the mechanical properties of the material and the crystallinity of continuous phase PP,it was found that,compared with simple blends,the SEBS/PP TPVs tensile curve appeared to be elastically stretched,And as the content of BIBP increases,the tensile strength,elongation at break,and tear strength of the material gradually decreased.As a cross-linking aid,S was more suitable for SEBS/PP TPVs than TAIC.The material had better comprehensive performance when the content of BIBP was 2 phr,By thermal performance analysis,the melting point Tm and melting enthalpy?Hm of PP in the material gradually decreased,and the system crystallinity slightly decreased with the increase of the content of cross-linking agent BIBP.The Scanning Electronic Microscopy?SEM?photographs showed clearly that,compared with the simple blend,the blending system of SEBS/PP was typical"sea-island"two phased structure by dynamic vulcanization.In order to improve the hardness of the materials and the fluidity of the materials,naphthenic oil and paraffin oil were selected as plasticizers,and the effects of the types and amounts of plasticizers on the properties of the materials was investigated.The results showed that by adding a plasticizer to the SEBS/PP TPVs system,the viscosity of the system decreased rapidly,the balance torque decreased significantly,the processing fluidity was effectively improved,and the system hardness was also significantly reduced.By the thermal performance analysis,the melting point and crystallinity of PP in the material decreased with the increase of the amount of plasticizer.Compared the mechanical properties,resilience and heat-resistant oxygen aging properties of naphthenic oil systems and paraffin oil systems,SEBS/PP/paraffin oil systems had better overall performance.The influences of filler system on the properties of SEBS/PP TPVs were discussed and the results indicated that for SEBS/PP/inorganic filler TPVs system,the system's balance torque,tensile strength,elongation at break,and tear strength gradually decrease,with the filler content increased,the hardness gradually increased with the filler content increased;for SEBS/PP/organic filler systems,the system's balance torque and tear strength gradually increased with the filler content increased,the breaking elongation gradually decreased with the filler content increased,the hardness gradually increased with the filler content increased,and the increase rate higher than inorganic filler system.Comparison of five types of filler systems,kaolin,calcium carbonate,mica powder,carbon black N330,and white carbon black,showed that the white carbon black system and mica powder system had better aging resistance,resilience and compression resistance. |
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