Characterization of maleic anhydride-grafted ethylene–propylene–diene terpolymer (MAH-g-EPDM) based thermoplastic elastomers by formation of zinc ionomer

Thermoplastic elastomers (TPEs) composed of maleic anhydride-grafted ethylene–propylene–diene terpolymer (MAH-g-EPDM) and ZnO were characterized using IR, TGA, solvent extraction, crosslink density, and physical properties. The degree of the ionomer formation increased with increasing the zinc oxide content, and it was also enhanced by adding stearic acid or zinc stearate. The crosslink densities were measured using a solvent swelling method using toluene, xylene, and 1,2-dichlorobenzene. The crosslink density increased when increasing the zinc oxide content. By adding stearic acid or zinc stearate, heteroionic bonds were formed and the crosslink density notably enhanced. The physical properties were dependent on the crosslink densities.