The Sub-Rouse Transition And Mechanism Of EPDM Composites

EPDM has its ozone resistance,heat resistance,excellent weather resistance,aging resistance.And in the process of practical application,EPDM is usually not used alone,in order to improve the mechanical and functional properties of rubber,usually need to fill a variety of inorganic particles.As well as to improve the physical and mechanical properties of the polymer,more important is endowed with some material price comparison valuable special functions.Although with filling inorganic nanoparticles to improve,but will affect the mechanical properties of polymer materials and use areas.This article focuses on the segmental relaxation behavior of EPDM,the improvement of the performance depends on the change of microstructure,rubber vulcanization network,then,the introduction of inorganic fillers is how to influence the EPDM rubber crosslinking network and the corresponding macro performance,is the key problem which needs to be settled.This thesis mainly study from the following three aspects:1.EPDM/CaCO₃ composite sub-Rouse change behavior.Through DMA data analysis,different content of nano calcium carbonate on the completely crosslinked EPDM chain segment networks to study the influence of the behavior of the structure is flabby,can get EPDM transition temperature is 385 k?i.e.,dynamic turning point?,the turning point of relaxation time of 0.18 s,the turning point occurs due to the transition temperature of intermolecular interaction is strong,due to the happening of the coupling in with the increase of temperature,changes in relaxation time became flat,make the growth trend of the chain segment motion is abate,constantly increase the amount of nanometer calcium carbonate,turning point temperature is gradually increasing,the turning point of relaxation time was gradually reduced,it more fully from the Angle of the micro confirmed that the introduction of inorganic calcium carbonate particles limits the EPDM chain segment motion.2.CaCO₃ of EPDM/PP/CaCO₃ composites sub-Rouse transformation behavior and mechanical properties of impact.Through XRD,DSC,TEM and DMA and mechanical performance test,in the crosslinked blend of EPDM/PP composite system,after our study found that the effect of sub-Rouse in the PP for EPDM can be ignored,with the increase of calcium carbonate,it increases the crystallinity of PP,at this time,the crystallinity of PP on EPDM chain segment motion obstacle occupied the main position,which reduces the EPDM chain segment and chi strength,make the turning point of temperature;When to 4 phr increased levels of calcium carbonate,calcium carbonate in EPDM occupied the main position,the increase of the content of calcium carbonate in EPDM chain segment distance 'increased,promoted the EPDM chain segment motion,makes the turning point of the temperature constant.3.PP chain of EPDM/PP/CaCO₃ composite materials yu chi behavior and mechanical properties of impact.In this paper,the preparation of EPDM/PP/CaCO₃ ternary nanocomposite,unlike before,this time is to change the organic matter of polypropylene on EPDM chain segment motion changes,we have adopted the crystallinity of DSC equipment for complex were measured,using dynamic mechanical analyzer to test chain segment motion,at the same time also have complex mechanics performance.DSC measurement results show that the crystallinity increased.Dynamic mechanical analyzer?DMA?of data shows that the nanoparticles limits the EPDM chain segment motion results in the decrease of the strength of the sub-Rouse shift peak,at the same time,the addition of polypropylene makes complex crystallinity increase,hindered the chain segment movement of EPDM,the same also results in the decrease of the strength of the sub-Rouse shift peak.At the same time also has carried on the mechanics analysis of ternary composites,polypropylene is enhanced,the tensile strength increased with the increase of content of PP increased,Due to the dispersion of the PP and EPDM the elongation at break decreases with the increase of content first increased.