Aramid fiber reinforced EPDM microcellular foams: Influence of the aramid fiber content on rheological behavior, mechanical properties, thermal properties, and cellular structure

In this paper, aramid fiber (AF)/ethylene-propylene-diene monomer (EPDM) microcellular foams added with different content of AF are prepared by the supercritical foaming method. The effect of the AF content on the rheological behavior, mechanical properties, thermal properties and cellular structure of the AF/EPDM microcellular foams has been systematically studied. The research illustrates that compared with pure EPDM, the AF/EPDM matrix has greater viscosity and modulus, which is conducive to reduce the cell size and increase its density. And the thermal stability of EPDM foams is improved with the addition of aramid fiber. Meanwhile, when the content of AF is added to 1 wt%, the AF/EPDM microcellular foam exhibits a relatively low thermal diffusion coefficient and apparent density with the thermal conductivity to 0.06 W/mK. When the AF is added to 5 wt%, the tensile strength of the AF/EPDM microcellular foam increases to 1.95 MPa, which is improved by 47% compared with that of the pure EPDM foam. Furthermore, when the compressive strain reaches to 50%, the compressive strength of the AF/EPDM microcellular foam is 0.48 MPa, improved by 296% compared with that of the pure EPDM foam.