Performance of Dynamically Vulcanized Thermoplastic Elastomer under Vibration Force Field

Abstract

The mechanism of vibration force field on dynamically vulcanized thermoplastic elastomers (TPE) is studied through the analyses of their mechanical properties, DSC, XRD, and TGA. Experimental results show that the tensile strength, tensile stress at 100%, and elongation at break of TPE increase within a certain range, but shore A hardness decreases with the increase in the vibrational frequency or amplitude. With the increase in the rubber and plastics ratio, the tensile strength, tensile stress at 100%, and shore A hardness of TPE decrease, but elongation at break increases. The mechanical properties of TPE processed in dynamic condition are better than those in steady condition. The interpenetration and entanglement of macromolecular chains between ethylene-propylene-diene terpolymer (EPDM) and polypropylene (PP) under vibration force field strengthen, the influence of amorphous component on the crystallinity of crystalline component increases, and the miscibility of two-phase interface increases. Therefore, introduction of vibration force field can improve the melting temperature, resistance to heat, and thermal stability of TPE, reduce the crystallinity of crystalline component PP, and increase vulcanization rate. Shearing and elongational effect of vibration force field strengthens deformation, fracture, fineness, and dispersion of EPDM in matrix PP, and side effect of over-vulcanization or degradation caused by local high temperature reduces, which enhances phase inversion of blending systems and realizes processing control of dynamic vulcanization, mixing dispersion, and reactant performance.