Study On The Performance Of TPO Sheet

This paper researched the effects of polypropylene?PP?,calcium carbonate?CaCO₃?on the properties of thermoplastic elastomer TPO sheet,and the effects of complex retardants?DBDPE-Sb₂O₃?,magnesium hydroxide?Mg?OH?₂?,montmorillonite?OMMT?on the flame retardant properties of thermoplastic elastomer TPO sheet.When TPO-CA10A/TPO-CA60A ratio was 80/20,the mechanical properties,the toughness and the melt flow rate of the blend of materials reached the best.The addition of PP and CaCO₃ improved the rigidity and Shore A hardness of TPO.When the addition amount of PP was 30phr and CaCO₃ was 40phr,the tensile strength of TPO/PP/CaCO₃ blend was 14.82MPa,improving 51.22%than TPO;right angle tear strength was 72.61N/mm,improving 23.91%;Shore A hardness reached 86.23°,increasing 16.17%.TPO/PP/CaCO₃ blend showed shear thinning pseudoplastic fluid characteristics by the study of melt flow rate and capillary rheometer.CaCO₃ improved the water resistance of the system,while reduced the water absorption of the blend.The TGA and SEM analysis showed,CaCO₃ improved the thermal stability of TPO/PP and the compatibility of TPO/PP/CaCO₃ was poor with the increase of the amount ofCaCO₃.The limiting oxygen index?LOI?test showed that,with the ratio of DBDPE/Sb₂O₃ increasing,the LOI decreased after the first increased,and when the ratio of DBDPE/Sb₂O₃ was 15/5,LOI researched maximum 24.3.At this time,the flame retardant of TPO/PP/DBDPE-Sb₂O₃ blend was the best.With the reduction of Mg?OH?₂ and the increase of DBDPE-Sb₂O₃,the tensile strength and tear strength of TPO/PP/Mg?OH?₂/DBDPE-Sb₂O₃ decreased after the first increasing.When the use of Mg?OH?₂/DBDPE-Sb₂O₃ was 14/36,it's LOI researched 28 and the vertical burning level reached FV-0.The TGA analysis showed,Mg?OH?₂/DBDPE-Sb₂O₃ reduced the maximum temperature of the heat loss rate and the heat loss rate,improving the flame retardant of materials.With increasing the use of organic montmorillonite OMMT,the LOI of TPO/PP/Mg?OOH?2/DBDPE-Sb₂O₃/OMMT increased.When OMMT was 3phr,LOI reached maximum 30.At this time,the vertical burning level reached FV-0.The XRD analysis showed,the layer spacing ofOMMT in TPO/PP/Mg?OH?₂/DBDPE-Sb₂O₃/OMMT increased,with the formation of intercalated structure.When the use of OMMT was 3phr,TPO/PP/Mg?OH?₂/DBDPE-Sb₂O₃?14/36?system burner surface showed continuous and dense carbon layer,what cut off oxygen to prevent heat transfer.The result showed that OMMT and Mg?OH?₂/DBDPE-Sb₂O₃ achieved a synergistic flame retardant effect.