Preparation and Properties of Semi-Transparent EPDM/Montmorillonite Nanocomposites

Abstract

Ethylene-propylene-diene rubber (EPDM)/organic montmorillonite (OMMT) nanocomposites were prepared through a melt-mixing process in an internal mixer. The nanoscale dispersion of OMMT in the EPDM matrix was verified by X-ray diffraction (XRD) and transmission electron microscopy (TEM), relating to an exfoliated morphology. The effects of OMMT content on the mechanical properties, curing behaviour, optical properties and thermal properties of the EPDM/OMMT nanocomposites were studied. The experimental results showed that OMMT had good reinforcement on the EPDM vulcanizates. The tensile strength and tear stress of the EPDM/OMMT nanocomposites significantly increased with increasing OMMT content. When the OMMT content was 15 phr, the tensile strength and elongation at break reached 19.8 MPa and 540%, respectively. The EPDM/OMMT nanocomposite cured by 2,5-dimethyl-2, 5-bis (tert-butyl peroxy) hexane was semi-transparent and the OMMT content had little influence on the curing behaviour of the nanocomposites. The increases in the glass transition temperature and thermal decomposition temperature were observed in the nanocomposites and were supposed to be related with the nanoscale dispersion of the OMMT and the strong interaction between EPDM and OMMT. Moreover, the permeability of oxygen for the EPDM/OMMT nanocomposites was reduced remarkably.