Investigation Of The Semitransparent EVA-base Cross-linked And Foamed Material And Application In Sport-sole Production

Transparent sports sole is favored by consumers for its beauty,however,they are mostly solid,therefore they are week in quality,elasticity.that was against with the development trend of light quality and high-performance for sports soles.EVA-based cross-linking foaming materials are widely used to produce sports soles for their high elasticity,shock absorption and light.However,it often loses transparency after processing even raw materials was transparent.In this paper,the optical model for polymer cross-linking foaming materials following non-imaging optics was simulated by LightTools optical software,which base on the mechanism of transparent modification of polymers and light scattering theory,and then the effects of relative refractive index,concentration and size of scattering particles on optical properties were discussed.Secondly,EVA as a matrix material,and EPDM and POE as modified materials was prepared to a EVA cross-linked foamed materials.The mechanical properties,crosslinking kinetics and thermal properties of materials were analyzed by universal material testing machine,vulcanizer and thermogravimetric analyzer,respectively.Otherwise,The optical properties of the material were studied by using ultraviolet-visible spectrophotometer and illumination meter and the effect of different formulation on the optical properties was discussed.Finally,The cell structure was analyzed by scanning electron microscopy to study a optical properties as a fucntion with different foaming ratio.The result showed that the metal ion compound as a raw materials has strong hiding power to visible light,therefore the transparency of the material can be loss remarkably.While the increse of mass fraction of POE and EPDM in the EVA/POE/EPDM foaming system,the hardness decreases,the density increases,the tensile strength,elongation at break increases and the tear strength all decrease,and the illumination decreases first and then increases.It was obtain a excellent comprehensive performance when EVA/POE/EPDM was 45/30/25,under this formulation,the density of material was0.2g/cm~3,the hardness was 52 Asker C,and the tensile strength,elongation at break and tear strength were 2.8 MPa,345%and 3.0 N/mm,respectively,and the illuminance was739 Lx.Additional talc can increase the hardness,tensile strength and elongation at break,while also significantly reducing the illuminance of the material.The Scanning electron microscopy(SEM)analysisr result showed that talc powder refined the cell size and increased the number of gas-solid two-phase interfaces,thereby increasing the frequency of photon scattering and causing the illuminance of the material to decrease.In EVA cross-linked foaming materials,with the increase of foaming ratio,the density,hardness,tensile strength,elongation at break and tear strength of the materials all decrease.The illumination of the materials increases first and then decreases with the increase of foaming ratio.It was obtain a excellent comprehensive performance when foaming ratio was 1.5 times.At this time,the density of the material is 0.24 g/cm~3,the hardness was 50 Asker C,and the tensile strength,elongation at break and tear strength were 2.7 MPa,343%and 3.1 N/mm,respectively,and the illuminance was 770 Lx.