One facile route to prepare high-performance radiation resistant EPDM rubber composites through graphite modification technology

Modification and improvement of aging resistance in nuclear power environment for the ethylene-propylene-diene (EPDM) rubber has been attracting the attention of scientists. In this article, graphite modified EPDM composites (ultrafine graphite [UG]/EPDM) were prepared, and effect of graphite with sizes of 13, 2.6, and 1.3 mu m on the processability, vulcanization parameters, mechanical properties, stability of radiation aging of EPDM composites were investigated, respectively. The results showed that EPDM rubber was an irradiated crosslinked polymer. The Mooney viscosity and crosslinking density of EPDM gradually increased with increasing graphite content under the effect of physical and chemical cross-linking of graphite. The lamellar structure of graphite particles in the rubber matrix is beneficial to improvement of the mechanical properties and aging resistance of the EPDM composites and play a reinforcing role, and the sp(2) hybrid structure of graphite can trap and quench free radicals, delayed the irradiation aging of EPDM. UG/EPDM composites irradiation stability was improved with increasing graphite dispersion in EPDM matrix. Under the cumulative irradiation dose of 1000 kGy, the tensile strength of blank sample and UG-2.6 mu m(-10) decreased by 51.1% and 17.7%, respectively, and the hardness increased by 8.7% and 4.9%, respectively. The energy storage modulus and the corresponding glass transition temperature (Tg) of UG/EPDM composites enhanced with graphite, while the thermal stability of the composites was improved.