Preparation And Mechanical Properties Of Graphene/TPEE Composites

Thermoplastic polyester elastomer(TPEE)is a high performance elastomer block copolymer with plastic and rubber properties.TPEE has good melting stability,thermoplasticity and processability.It can be molded by injection,extrusion and blow molding,and has recycling characteristics.But its tensile and bending strength can not meet the use requirements of high rail pad.In this paper,the TPEE underneath the high-speed rail was taken as the object to study its forming process and determine its optimal forming process parameters.The composites were prepared by blending and melting it with graphene,and the effects of different graphite components on the mechanical properties of TPEE were investigated.(1)The TPEE injection molding process was simulated by MOLDFLOW software.The results of orthogonal test showed that the optimal injection process parameters were mold temperature 50℃,melt temperature 200℃,injection+packing+cooling time 24 s.(2)Using ANSYS software for static analysis of TPEE,the maximum deformation is 2.29mm under the actual working condition load(90KN);the maximum stress is 40.8MPa,which meets the requirements of the high-speed rail underlay.(3)Graphene/TPEE composites were prepared by blending melting method.The results of scanning electron microscopy and transmission electron microscopy showed that graphene caused the stacking and delamination of TPEE structure,resulting in dispersion strengthening and plasticizing effect.(4)Through static and dynamic mechanical analysis,the results show that the tensile strength and flexural strength of graphene/TPEE composites change with the different graphene components.When the graphene content is 0.4 wt%,the tensile strength and flexural strength increase,the maximum values are 23.4 MPa and 22.8 MPa,respectively.